WO1992020117A1

WO1992020117A1 - Antenna and small portable radio device

Info

Publication number: WO1992020117A1
Application number: PCT/JP1992/000581
Authority: WO
Inventors: Norio Hama
Original assignee: Seiko Epson Corporation
Priority date: 1991-05-09
Filing date: 1992-05-06
Publication date: 1992-11-12
Also published as: EP0538485A1; HK1000299A1; EP0538485B1; DE69216983D1; EP0538485A4

Abstract

An antenna which can provide a radio device stable and highly sensitive irrespective of its attitude or its carried direction and of the effect of the proximity to a human body when it is carried with the human body. When the radio device having this antenna is not carried with a human body, regardless of the plane of polarization of an electromagnetic wave, i.e., even in a place where the plane of polarization under multipath distorsion and fading is always changed, the radio device has a stable sensitivity characteristic. Also, the antenna circuit achieving these characteristics requires no additional element for matching, and has a remarkable effect on reducing the size of a radio device.

Description

-I- 'Description antenna and small portable radio [Technology]

The present invention relates to a small portable wireless device, particularly to an antenna and an antenna circuit system.

[Background technology]

Conventionally, the use of a loop antenna as an antenna for a small portable radio has been described in the paper "Small Portable Radio." Loop antenna: As widely clarified in National Technical Report Vo 1.19 No. 2 APRIL 1973, it is widely used widely. In addition, there is an example where a fixed leakage element is incorporated between loop antenna elements. In addition to the loop antenna, as an antenna for transmitting and receiving a frequency 'with a relatively high frequency, an inverse F antenna is also used. It is.

[Issues to be solved by the invention]

Since small portable radios are always used while being carried, the transmission / reception characteristics of the radio are greatly affected by the human body. A typical example of a small portable radio is a selective call receiver. Antennas can be cited as circuit elements that greatly increase the sensitivity of the receiver to the left and right, but the antennas of the selective calling and receiving receivers are listed. For this reason, loop antenna ₄ is commonly used. When the loop antenna is placed with the direction facing the front of the human body, the magnetic field components are detected efficiently and the gain s 6 dB The phenomenon of improving is a fact that is well known as described in the above-mentioned article, but when it is placed in a direction other than that. There is a problem that the loop antenna does not work and the profit is reduced. In addition, even when the human body is not worn, radio waves having a polarization plane in one direction can be received well, but in other directions, it is extremely received. There is a problem that the signal characteristics drop.

This means that the transmission / reception sensitivity changes depending on the attitude of the radio, and it is extremely inconvenient for the user. That is the case.

In addition, the above-mentioned article states that the arrangement of the ground plane and the loop antenna element, which use the wireless device main body substrate, is in a direct relationship with the magnetic field. Detects the components of both the electric field and the electric field, and reduces the difference in directionality due to the attitude of the radio equipment. If the position of the radio is set to detect electric field components in the country, the sensitivity will drop by 7 dB on average. .

In addition, when the attitude of the wireless device is set to detect magnetic field components when wearing a human body, the sensitivity sensitivity is 5 dB on average. As shown above, in fact, electric field components are also detected little by little, so the effects of their proximity to the human body are appearing. The improvement in sensitivity is only about 3 dB, and there is a problem that the effects of the human body are not used effectively. In addition, when the body is not worn, time or distance may be affected by fluctuations in the polarization plane under multi-ino, multi-pole, or fusing. There is a problem that the characteristics of radio equipment deteriorate periodically over time.

-On the other hand, if the loop antenna itself is too short for the signal wavelength to be used to be invisible, the impedance is locally limited. High or low; when the human body or the object with a high dielectric constant approaches the high impedance part, the impedance becomes high. The misalignment causes mismatching, which lowers the transmission / reception sensitivity.

The present invention provides an antenna capable of solving the following problems and improving the transmission / reception sensitivity of a wireless device.

[Disclosure of Invention]

The antenna of the present invention includes a loop antenna element, a wireless transmission / reception circuit, a data decoder circuit, a CPU circuit, and a data circuit. In a small portable radio consisting of a display unit and a notification circuit unit,

The loop antenna element described above has a loop shape with two conductors, a first loop antenna and a second loop antenna. One terminal of the first loop antenna is connected to the first variable capacitance element, and the other terminal is one of the second variable capacitance elements. Terminal of the second loop antenna is connected to the terminal.

2 Characteristically, it is connected to the other terminal of the variable capacitance element, and the other terminal is connected to the high frequency grounding surface on the substrate. And

Also, the high frequency grounding surface of the antenna of the present invention is It is characterized in that the side that is perpendicular to the loop antenna element has a longer rectangular surface than the side that runs along the longer side. In addition, the first and second variable capacitance elements used in the antenna of the present invention have a capacitance value due to voltage being applied to both ends of the element. It is characterized by changing

In addition, one of the combinations of the capacity ratio of the second variable capacitance element value to the first variable capacitance element value described above used for the antenna of the present invention. The first is determined to be equal to the element length ratio of the first loop antenna element to the second loop antenna element. This is the feature.

In addition, the voltage used for the antenna of the present invention is characterized in that it changes according to the attitude of the aforementioned small portable radio.

In addition, the antenna of the present invention is equipped with a switch that switches the voltage according to the attitude of the portable wireless device described above. It is characterized by

In addition, a portable wireless device featuring the antenna of the present invention will be configured.

Further, the loop antenna of the present invention includes a loop antenna element, a wireless transmission / reception circuit section, and a data decoder inside the housing. , A CPU circuit, a data display section, and an information circuit section, and operate the small portable radio described above in a small portable radio. The long direction length of the circuit board on which the circuit is mounted is between 1/10 and 1-6 of the transmission / reception wave length of the radio equipment. The loop antenna has an opening area in the direction perpendicular to the direction, and the loop antenna length is equal to the length of the wireless device. The feature is that the transmission / reception wave length is between 1/10 and 1-6.

In addition, the length of the circuit board on which the loop antenna is mounted is substantially the same as the length of the loop antenna and the length of the loop antenna. It is unique.

Then, a small-sized mobile radio device featuring the above-mentioned antenna will be constructed.

In addition, the loop antenna of the present invention divides the total length of the loop antenna element described above into two from 6: 1 to 8: 1 and divides the total length of the loop antenna element into two. The longer one is the first loop antenna and the shorter one is the second loop antenna, and one terminal of the first antenna element is The other terminal is connected to the common potential pattern of the wireless device, and the other terminal is connected to one terminal of the second antenna element and the capacitive reactor. It is characterized in that it is connected via a sense element.

In addition, the length of the circuit board on which the loop antenna is mounted, the length in the lateral direction of the circuit board, the length of the first antenna element and the length of the second antenna. The feature is that the sum with the element length is almost the same.

Further, the loop antenna of the present invention includes a loop antenna element, a wireless transmission / reception circuit section, and a data decoder inside the housing. , A CPU circuit, a data display unit, and a notification circuit unit, a small portable radio unit, which is a part of the loop antenna. It is characterized by the fact that it has a slot and a solitary cut.

In addition, the arbitrary points of the two conductor plates sandwiching the above-mentioned cut section are described. The feature is that the capacitive reactance elements that are connected to each other are mounted.

In addition, one of the two conductor plates sandwiching the above-mentioned cut portion is connected to the common potential pattern of the above-mentioned wireless transmission / reception circuit. It is characterized by

In addition, any other point of the two conductor plates sandwiching the cutout portion is connected to the high-frequency input terminal of the wireless transmission / reception circuit. This is the feature.

In addition, the loop antenna element including the above-described cut portion is formed in two pairs via another capacitive reactance element. And are characterized.

Also, the above-mentioned capacitive reactance element is characterized in that it is mounted at a position opposite to the center position of the above-mentioned cut portion. You.

Then, a small-sized portable radio device featuring the above-mentioned antenna will be constructed.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of the antenna of the present invention viewed from the opening side. Fig. 2 is an antenna circuit diagram including the antenna of the present invention. The figure shows a perspective view of the arrangement of the loop antenna of the present invention, and FIG. 4 shows the arrangement of the NORD-cap diodes 14 and 15 in FIG. Fig. 5 shows the applied voltage and the change in capacitance, Fig. 5 shows the finger-direction characteristics when the body is worn, and Fig. 6 shows the radio equipped with the antenna of the present invention. Figure 7 is an external view of the machine, Fig. 7 is a view when the radio described in Fig. 6 is mounted on a hoster, and Fig. 8 is the antenna of the present invention. The figure with the mercury switch built into it so that the radio equipped with the antenna can detect its attitude, and Fig. 9 shows the antenna of the present invention. A figure with a built-in mouthpiece so that the radio equipment provided can detect its attitude.Figure 10 shows the example of Figure 9 on the circuit. Fig. 1 shows a human body equipped with a wireless device equipped with the antenna of the present invention, and Fig. 12 shows an arm mounted type of the antenna of the present invention. Fig. 13 shows an example of Fig. 12 with a human body mounted on it, and Fig. 14 shows the antenna of the present invention with a circuit board. Fig. 15 is a top view of the antenna mounted on top, Fig. 15 is a cross-sectional view of the antenna section when viewed from the X direction in Fig. 14, and Fig. 16 is 15 Compared to the figure, the loop Figure 17 shows a capacitor inserted in the middle of the antenna, Figure 17 shows the electrical behavior of the antenna shown in Figure 16, Figure 1 Fig. 8 shows the output impedance trajectory of the antenna of the present invention. Fig. 19 shows the pointing characteristic diagram of the antenna of the present invention. Figure 0 shows the orientation characteristics of the antenna of the present invention, and Figure 21 shows the appearance of a small portable wireless device incorporating the antenna of the present invention. Fig. 22 is an example of human body wearing of the small portable radio of the present invention, and Fig. 23 is a part of the conductor plate of the antenna of the present invention in the antenna. Fig. 24 shows an example where a cut is made in the cutting part (slit), and it is easy to see what kind of magnetic field component can be detected in this embodiment. The figure shown and Fig. 25 are FIG. 26 shows an example in which the antenna of the example is mounted on a circuit board, FIG. 26 shows another example of the antenna of the present embodiment, and FIG. 27 shows a key of the present embodiment. Figure 28 shows an example of applying the antenna to an arm-mounted type of wireless machine. Figure 28 shows the connector for attaching and detaching the arm node in Figure 27. Electric Fig. 29 'is a cross-sectional view explaining the characteristics, and Fig. 27' is a circuit diagram in which the connector is not used as an electric circuit and the arm is used as a capacity. Fig. 3 is an example of an antenna configuration.

[Best mode for carrying out the present invention] The details of the present invention are described below by way of examples.

Fig. 1 is a cross-sectional view of the antenna of the present invention viewed from the opening side. The first loop antenna 1 and the second loop antenna 2 are connected at the connection points 6 and 7 via the second variable capacitance element 4. You. The second loop antenna 2 is connected to the inner layer pattern 10 of the substrate 3 at the connection point 8. The inner layer pattern 10 extends over the entire surface of the substrate 3. The other terminal of the first loop antenna 1 is connected to the first variable capacitance element 5 via a connection point 9. The other terminal of the first variable capacitance element 5 is connected to a high frequency amplification circuit (not shown in the figure). As a result, a one-turn loop antenna is formed.

FIG. 2 is an antenna circuit diagram including the antenna of the present invention. The variable capacitance elements 4 and 5 correspond to the barrier diodes 14 and 15, respectively. In parallel with the first normal capture diode 15, a manually operated variable capacitor 20 is connected, and further, the ground 18 is connected to the ground. During this time, Canon 22 is connected. Earth 18 is the DC potential of the inner layer pattern 10 in FIG. As a result, loop antennas 11 and 12 and normal cap diodes 14 and 15 and a variable-capacity diode 20 and key According to Yano \ 'Sita 2 2, An LC resonance circuit is configured to resonate at the desired frequency. Terminal 23 is a connection point to the high-frequency amplification circuit. The Variable Capacitor 20 is designed to match the maximum radio sensitivity.

At the connection point 19, a DC voltage is impressed via the resistor 21. The resistance 21 is a high resistance and is a value that does not lower the Q of the antenna. The resistor 21 is connected to the switching switch 24. Switch 24 switches the terminal to be conducted depending on the attitude of the wireless device. Resistors 25a, 26, 27, 28 'determine the two dc voltages applied to switch 2. The power supply terminal 13 is connected to a power supply that drives a radio circuit.

The voltage settings are as follows: terminal 23, connection point 19, and ground 18 from the higher side. As a result, a reverse voltage is applied to the NORCAP diodes 14 and 15 and the voltage at the connection point 19 changes the voltage at the terminal 23. If it is changed within a range that cannot be exceeded, two combinations of the values of the barrier diodes 14 and 15 can be obtained. In each combination, the impedance characteristics when the loop antennas 11 and 12 'were viewed from the terminal 23 remain the same. . Therefore, since the matching in the reception frequency does not change, the sensitivity does not decrease due to the shifting of the matching. According to the present invention, the capacity on the loop antenna can be set by setting two types of capacity ratios of NORCAP diodes 14 and 15. By changing the flow distribution and controlling the amount of detection of electric field components, it is possible to prevent fluctuations in sensitivity due to differences in the attitude of the wireless device when wearing a human body. It is intended for.

FIG. 3 is a perspective view showing the arrangement of the loop antenna of the present invention. A loop antenna 1 is arranged along the short side of the substrate 3. In this case, the loop antennas 1 and 2 act as magnetic field detection antennas, and the inner layers of the substrate 3, the 'turn 10' and the The loop antennas 1 and 2 work as the electric field detection antenna. If a magnetic field component 101 and an electric field component 102 have a relationship as shown in the figure and an electromagnetic wave arrives, the short side of the substrate 3 is set to the electric field component 1 When the switching switch 24 is in a predetermined position, the magnetic field is set up in a posture erecting along the direction 02 (hereinafter referred to as a horizontal position). It works only as an antenna, and when the long side of the base plate 3 is in an attitude standing along the electric field component 102 (hereinafter referred to as vertical installation) ) Works as an electric field antenna and a magnetic field antenna. Also, when placed as shown in this figure, it works as an electric field or magnetic field antenna.

FIG. 4 is a diagram showing the applied voltage and the capacitance change of the barrier diodes 14 and 15 in FIG. FIGS. 4 (a) and 4 (b) show examples of the first NORCAP diode 15 and the second NORMAL diode 14, respectively. is there. When placed in a horizontal position, diode 15 is at point 32 and diode 14 is at point 37. These values and the combined capacity of the real-time capacitor 20 and the capacitor 22 are the same as those of the loop antennas 11 and 12. Resonate at the frequency. At such a capacitance ratio, it becomes a magnetic field antenna and does not work as an electric field antenna. When the switch is placed in the vertical position, switch 24 is switched, and diode 15 is at point 31 and diode 14 is at point 38. It changes to the position. In this case as well, they resonate at the same reception frequency. At such a capacity ratio, the force acting as an electric field antenna, works also as a magnetic field antenna.

In this way, when the antenna is placed horizontally, it only works as a magnetic field antenna because the sensitivity increases when the body is worn. That's why. In addition, the reason why the antenna works as an electric field antenna when it is installed vertically is that the electric field antenna has a low sensitivity when the body is worn. This is to compensate for the bleeding and to prevent fluctuations in sensitivity due to the attitude difference of the radio.

The capacity ratio of the first and second NORCAP diodes 15 and 14 when placed horizontally is C12: C22, but this value is the second. The element length ratio of the loop antenna 12 and the first loop antenna 11 is determined to be equal to the element length ratio. By doing so, the inner layer pattern 10 inside the substrate 3 and the loop antennas 1 and 2 do not become electric field antennas, but magnetic field antennas. Only works as an antenna. In the vertical installation, the capacitance ratio is C11: C21 in the figure, but if this ratio is changed, the efficiency as an electric field antenna will change. Can be adapted to the characteristics required when wearing a human body5.

Fig. 5 shows the direction characteristics when wearing a human body. (A) is for the case of horizontal installation, and (b) is for the case of vertical installation. In (a), the graph 80 works as a magnetic field and an electric field antenna, and the graph 81 works only as a magnetic field antenna. In this case, graph 86 The behavior of the magnetic field antenna alone is the characteristic when it is placed in the space. The graph 86 also shows the characteristics of the electric and magnetic field antennas when operated in space. The difference in frontal sensitivity between the graph 81 and the graph 86 is large, and-operating only as a magnetic field antenna is more effective for human body. It can improve the characteristics of frontal sensitivity when wearing it. Here, a reference sensitivity level 88 showing the front sensitivity of the graph 86 is shown. In (b), the graph 83 works as a magnetic field and an electric field antenna, and the graph 82 works only as a magnetic field antenna. The graph 87 is a characteristic when a magnetic field or an electric field antenna is placed in a space. When operated as an electric field antenna, the front sensitivity characteristic decreases when the body is worn. The reference sensitivity level 88 of the force (a) is reduced to the upper surface. The frontal sensitivity value has been obtained. 'From this, it can be seen that the magnetic field antenna operates only when mounted, and the magnetic field and electric field antennas operate vertically when mounted. No matter how the antenna is worn on the human body, the antenna will always have stable characteristics. In addition, even when the antenna is placed as a single unit in the space, if it acts as a magnetic field or an electric field antenna, the high sensitivity is not related to the fluctuation of the polarization plane. can get.

Fig. 6 is an external view of a wireless device equipped with the antenna of the present invention. The display panel 41 attached to the upper center of the main body 40 displays the received content, time, etc. The switch 47 is for changing the display of the display panel 41. The switch 42 at the bottom of the recess 43 at the bottom of the main unit is It is intended to detect the attitude of the aircraft.

Fig. 7 is an example of the case where the wireless device described in Fig. 6 is mounted on a holster. The holster 46 is a force ⁵ that is a case for carrying a wireless machine by attaching it to a waist belt, etc., and the bottom inside the holster There is a protrusion 45 in the section, and when a wireless device is inserted into the holster 46, the protrusion 45 is applied to the switch 42 and the force 5 is applied to the switch 42. Will be pressed. This switch corresponds to the switching switch 24 shown in FIG. 2, and is a switch.

4 When 2 is pressed, it becomes an antenna that operates only as a magnetic field antenna. When removed from the holder, switch 24 is released and acts as a magnetic or electric field antenna. Until then, for example, if you stand in a pocket on your chest, etc., it will work as an electric field antenna, so there will be no drop in sensitivity. . Also, as is clear from Fig. 5, when a single wireless device is placed in the space, the switch 24 is released and the magnetic switch is released. It becomes a field and electric field antenna, and a stable sensitivity characteristic can be obtained in any posture.

Figs. 8 (a) and (b) show a radio-silver switch equipped with the antenna of the present invention, which has a mercury-silver switch built in to detect its attitude. This is an example. In this case, the switching switch 24 shown in Fig. 2 is driven by conducting or not conducting the mercury switch.

In (a), when the wireless device 54 is placed horizontally, the mercury switch 51 is in an upright state. Water silver pillar inside

50 occupies half of the capacity of the cylinder 52, but the electrodes 53, 55 at both ends of the cylinder 52 are connected to each other. Not in. In this case, the antenna operates only as a magnetic field antenna. In (b), when the wireless device is installed vertically, the mercury switch 51 is in the horizontal position. The water silver pillar 50 in the inside connects the electrodes 53, 55 on both ends of the cylinder 52 to each other and conducts. In this case, it operates as a magnetic field or electric field antenna. The antenna characteristics during operation are as described in FIG. Figs. 9 (a) and (b) show a radio cell equipped with the antenna of the present invention, which has a built-in load cell because it can detect its attitude. This is an example. This load cell also corresponds to the switching switch 24 in FIG. There are many different types of load cell 61, but here we will describe examples of resistance value variations. In (a), when the wireless device 60 is placed horizontally, the spring 63 included inside the cylinder 64 is replaced by the weight 62 Due to the load, the mouth cell 61 is stretched by a wire 68 connecting the weight 62. Electrodes 66 and 67 provided at both ends of the load cell 61 are connected to the antenna circuit. The resistance between the electrodes 66 and 67 is determined so that it operates only as a magnetic field antenna.

In (b), when the wireless device 60 is installed vertically, the load of the weight 62 is not transmitted to the wire 68, so the load cell 6 1 is not good. At this time, the resistance value between the electrodes 66 and 67 is different from that in the case of (a), and it is decided to operate as a magnetic field or an electric field antenna. You. The spring 63 selects a spring having a relatively large spring coefficient to prevent the vibration of the weight, which is caused by the vibration. FIG. 10 is a diagram showing the example of FIG. 9 in a circuit. The variable resistance 25b corresponds to the load cell 61. Electrodes 66 and 67 correspond to terminals 29a and 29b. Figs. 11 (a) and (b) are examples of a radio body equipped with the antenna of the present invention mounted on a human body. In (a), the holster 71 attached to the waist belt 72 is used when carrying the wireless device sideways. You. In addition, in (b), it is general that a wireless device 74 is mounted vertically on the breast pocket 73. In both cases, the sensitivity characteristics of the radio are obtained with a stable high sensitivity.

Fig. 12 is an example in which the antenna of the present invention is applied to an arm-mounted radio. A loop antenna is incorporated in the inside of the arm belt 90, and a display panel 92 and a switch 93 are arranged on the front surface of the main body 91.

FIGS. 13 (a) and 13 (b) are examples of wearing the human body in the example of FIG. (A) The attitude of the radio 95 when walking or standing upright, and (b) the attitude of the radio 95 when seated is clear. It is completely different. In such a case, the use of the antenna of the present invention can provide stable characteristics in any posture.

Although the embodiments have been described above, the present invention is not limited to the embodiments described above, but is a wireless device that can be widely mounted on the human body in various postures. It is possible to use the switch of the gravity sensor type in many ways to detect the attitude of the radio equipment. It is. Also, as another example, the polarization component of the interference wave is measured to improve the interference characteristics of the radio wave, such as a measuring device that detects the polarization plane of the radio wave and the radio equipment. It can be applied to circuits that are automatically removed.

FIG. 14 shows an example relating to the length of the circuit board among the antennas of the present invention.

FIG. 14 is a diagram of the antenna of the present invention mounted on a circuit board and viewed from directly above.

On a circuit board 202, a loop antenna 201, a wireless transmission / reception circuit element 204, 200, 206, and a display cell 203 are provided. It is located. Although the digital circuit is not shown in 201, noise may occur and it may be mixed into the wireless part or the antenna. Due to its potential, it is placed away from both blocks or placed below the display panel 203.

The loop antenna 201 is formed by bending a flat plate into the shape of a loop antenna. The arrangement is in a direction perpendicular to the X-Y direction, that is, the longitudinal direction of the circuit board 202. The length 207 in the longer direction is about Z8 with respect to the transmission / reception frequency wave length.

FIG. 15 is a cross-sectional view of the antenna section when viewed from the X direction in FIG.

The loop antenna 201 surrounds the circuit board 202 as shown in the figure, and its length is about eight. The connection point 208 with the circuit board 202 is connected to the common potential of each circuit section mounted on the board 202, for example, the ground potential. It is connected to the same pattern as another print node's turn. Also, The connection point 209 is connected to a high frequency amplification circuit located at the next stage of the antenna. The circuit board 202 is a multi-layer board, and the inner layer is hired with at least a ground potential that is at least a ground potential. The board area is covered.

Fig. 16 shows the loop antenna 201 divided in the middle of Fig. 15 and the first loop antenna 210 and the second loop antenna. This is an example in which a capacitor 2 13 is inserted between the terminals 2 10 a and 2 10 b, and a capacitor 2 13 is inserted between the terminals. You. The capacitor 2 13 is inserted so that the ratio of the first loop antenna 2 11 to the second loop antenna 2 12 is 7: 1. are doing. If the ratio of the first loop antenna 2 1 1 is large, the antenna gain when the antenna is in a dipole operation is large. However, the impedance difference when approaching the human body also becomes larger, and overall, the effect of the impedance difference becomes larger. It is. This is because the shadow effect also appears during the original loop antenna operation, so that the sensitivity of the wireless device is generally lower when wearing a human body. You. For this reason, it is better that the ratio of the antenna 211 is not extremely large.

-On the other hand, if the ratio of the first loop antenna 211 is small, the impedance when the body is close to the body will be small, but The antenna gain at the time of the loop operation is greatly reduced, and the gain at the time of the loop antenna operation is not changed. In such an antenna, the sensitivity difference depending on the direction of the wireless device is large, and therefore the present invention is well suited for the purpose of the present invention.

The present invention is based on the first loop antenna 211 and the second loop antenna. By making the ratio of the antenna 2 12 approximately 7: 1, the shadow at the time of the close proximity of the human body is suppressed small, and at the time of the dipole operation. The company also secures a profit on the antenna.

FIG. 17 is a diagram for explaining the electrical operation of the antenna shown in FIG.

When operating as a loop antenna, the first loop antenna 21 1, the capacitor 2 13, and the second loop antenna 2 1 2, capacitors 2 14, 2 15, and their respective connection points 2 08, 2 0 9, 2 1 0 a, 2 1 0 b, 2 1 8, 2 The lubricated circuit composed of 19a functions as an antenna. The electromotive force is input to the high-frequency amplification circuit 211, the potential difference from the connection point 219b is increased, and the voltage appears at the output terminal 217. It is. The circuit board 202 has a common electric potential pattern of the circuit 216 and the loop antenna.

During operation as a dipole antenna, the common potential pattern of the circuit board 2 is applied to one of the elements of the dipole part. And The other element is the first loop antenna 211. There are connection points 219a and 219b between the middle of these two elements. Before the connection point 21 Ob, there are a capacitor 21 3 and an antenna 21 2, etc., but the capacitor 2 13 Because of the pedestal value, it is possible to assume that nothing is connected beyond the connection point 210b during dipole operation. it can.

The total length of this dipole antenna is ぇ 8 (circuit board length) ÷ / * 8 * 7 88 (first loop antenna). With such a length, it is not considered a so-called microscopic dipole, and an electric field distribution occurs on the antenna, and its shape is changed. The shape is similar to that of the dipole antenna.

In that case, the impedance of the connection point supplied to the circuit 216 becomes lower, and the matching condition on the circuit 216 side is not satisfied. It's always getting closer.

FIG. 18 is a diagram showing the output impedance trajectory with respect to the frequency of the antenna of the present invention. The output impedance trajectory 2 26 is shown on the Smith diagram 22.

The impedance point 2 21 is when the antenna shown in Fig. 16 is used, and when the capacitor 2 14 matches the optimal point. The impedance point 2 2 2 is an impedance that minimizes the number of noises on the circuit 2 16 side, and is a circle 2 2 3 Is an isomorphic exponent circle in which the index of noise is connected to the same impedance.

The impedance point 2 2 2 has a value near 50 + 50 j (Ω), and the closer the value is to this value, the closer the value of the wireless device becomes. The chin gets better. When used as a dipole antenna, impedance conversion at the power supply point is low, and impedance conversion is performed. It is possible to get closer to the impedance point 2 22 without having to almost eliminate the noise.

This means that there is no need to add new electronic elements for impedance conversion, and therefore small and small. It means that you can configure a lost antenna circuit. The impedance point 2 25 is the impedance when the antenna circuit shown in FIG. 16 is brought close to the human body. It hardly changes compared to the impedance point 222.

— On the other hand, the impedance point 2 2 4 moves the capacitor 2 13 shown in Fig. 16 to the vicinity of the connection point 2 09, and the 2nd loop antenna This is the impedance when it comes close to the human body without the knurls 212. This is the case when the example of the antenna shown in Fig. 15 is used. Compared to the impedance point 2 21, the deviation is large, and the sensitivity drop is inevitable.

As can be seen, using an antenna as shown in Fig. 16 can reduce the effects of close proximity to the human body. Fig. 19 and Fig. 20 show the pointing characteristics of the antenna of the present invention. In Fig. 19, the electric field polarization plane is vertical, the XY axis in Fig. 14 is placed so as to be vertical to this, and the Z axis is rotated around the center. This is an example. This is called the horizontal state. The direction of the front surface is the direction when the radio wave arrives from right above the paper surface and it is placed as shown in Fig. 14.

The graph 23 1 is a single body, and the graph 23 2 is a characteristic when the body is worn. In the frontal direction, the antenna gain when worn on the human body shows an increase of several dB. This is because the antenna of the present invention operates as a loop antenna.

Similarly, in FIG. 20, the electric field polarization plane is set to be vertical, and the XY axis in FIG. 14 is set so that it is parallel to the XY axis. This is an example of rotation around the center. This is placed vertically It is called. FIG. 20 is a diagram that most clearly shows the effect of the present invention. Graphs 24 1 and 24 3 are both gains from the antenna alone, but the former is the antenna of the present invention shown in Fig. 15 and the latter is the latter. The operator can set the length of the loop antenna 201 in FIG. 15 to half the length of the circuit board 202, or the loop antenna 201. This is an example of the case where the length of the circuit board 202 is halved as it is.

The difference between the graphs 24 1 and 24 3 is 10 dB, which indicates that the circuit board 202 and the loop antenna are different from each other as in the present invention. The circuit board 201 has almost the same length, so that the circuit board 202 can efficiently pick up the electric field component of the radio wave, and the circuit 2 16 The received signal can be sent to the server. However, although the gain of the circuit board 202 as an antenna is slightly reduced by using the antenna shown in Fig. 15, 18 As shown in Fig. 18, the effect of the close proximity to the human body can be greatly reduced.

The graph 242 is an antenna gain obtained when the antenna is attached to the human body with respect to the graph 241. Because it is an antenna that picks up electric field components, the sensitivity drop on the front of the human body is inevitable. This is also evident in the papers mentioned in the explanation of the conventional example. However, the absolute level of the graph 24 2 can be maintained at almost the same level as compared with the antenna gain shown in FIG. In other words, regardless of the direction in which the human body is worn, the profit will not change much.

This is achieved by incorporating the antenna of the present invention into a wireless device. In this case, it means that the sensitivity will hardly change even if you carry the mobile phone in any direction, and you will get the characteristics suitable for a mobile phone. You can do it. Of course, in contrast to the example shown in Fig. 16, only a small decrease in the gain of the antenna itself occurs, but the reception sensitivity is almost the same. Undirected characteristics can be obtained.

Fig. 21 shows an example of a small portable wireless device incorporating the antenna of the present invention. The display panel 251 is arranged horizontally, and when confirming the display, each operation is performed in the horizontal state as shown in the figure. Buttons 25 2 and 25 3 are input switches for performing operations. The main body 250 is usually mounted in the horizontal direction as shown in the figure. For example, as shown in Fig. 22 (a), attach the holder 262 near the waist of the human body 261, and attach the main body 25 to the holder 262. Attach a 0. In this case, the main body 250 is mounted horizontally. If the holder 26'2 can be tilted when needed, the display can be checked as it is when it is mounted on the holder 262. It is convenient to take it out. Holder 262 is integrated with belt 260 and can be easily wound by winding belt 260 near the waist of human body 261. Can be installed.

When the main body 250 is inserted into the pocket 263 near the breast of the human body 261, as shown in FIG. 22 (b), the main body 250 may be inserted. Is in the vertical S state, and is inserted into the pocket 263.

In this case, the body is mounted vertically.

As described above, the body 250 incorporating the antenna of the present invention is described above, although there are various ways of carrying. The antenna gain is almost the same whether the player is in the horizontal position or the vertical position when wearing the human body. Even so, the sensitivity is almost the same and it is convenient to carry.

FIG. 23 shows another embodiment of the antenna according to the present invention, which is related to the antenna itself.

Fig. 23 shows an example of the antenna of the present invention, in which a cutout (slit) is provided in a part of the conductor plate.

The conductor plate 301 forms a loop antenna together with the capacitor 303. The conductor plate 301 includes a slit 302 as a part thereof. At any position in the slit 302, there are connection points 3110 and 311 and a capacitor 304 that connects the points to each other. The position at which the capacitor 304 is connected can be any position within the slit 302. The connection point 310 is connected to the ground 305. At any point of the conductor plate 31 which runs parallel to the slit 302, there is a power supply point 310, which is used for the antenna circuit alignment. It is connected to a high-frequency amplification circuit 307 via a capacitor 306. The output of the circuit 307 is connected via a terminal 308 to a subsequent intermediate frequency circuit or the like. The capacitor 303 is located on the loop antenna so as to face the slit 302 at a certain position.

There is a slit in a part of such a conductor plate, and the antenna that supplies power without the slit is generally called a slot antenna. I'm calling, but the antenna of the present invention is A special feature is that a part of the conductor plate that forms the antenna also works as a slot antenna.

A feature of slot antennas is that they efficiently detect magnetic field components in the same direction as the direction in which the slit extends. Therefore, it is possible to detect a magnetic field component in a direction orthogonal to the magnetic field component detected by the loop antenna.

FIG. 24 is a diagram simply showing what magnetic field components can be detected in the present embodiment.

The loop antenna composed of the conductor plates 3 2 1 and 3 3 2 and the capacitor 3 2 3 detects the magnetic field component 3 3 5. Then, a slot antenna composed of the slit 322 and the capacitor 324 detects the magnetic field component 337. In addition, by making the positions of the connection points 3330 and 331 any positions of the slit 322, the slit 322 is taken out. The surrounding conductor plate 332 and the capacitor 324 serve as a loop antenna, and the magnetic field component 336 is detected.

The magnetic field components 335, 333, 337 are in a direct relationship with each other. Therefore, the magnetic field component can always be detected regardless of the attitude of the antenna of this embodiment. In addition, having such characteristics is extremely inconvenient for radio equipment that is worn on the human body and used.

FIG. 25 shows an example in which the antenna of this embodiment is mounted on a circuit board. The conductor plate 34 1 is mounted on the circuit board 35 2. Each capacitor or circuit 347 is represented by an electrical circuit symbol. In this figure, capacitor 3 4 3 and slit 3 4 2 is not facing. The conductor plate 35 5 and the circuit board 35 2 are connected by the conductor plates 35 3 and 35 4. Conductor plate 35 5 3 is for power supply, conductor plate 354 is for ground, and connected to connection points 3 29 and 3 30 in Fig. 24 respectively. This corresponds to point 3 3 1.

FIG. 26 is another example of an antenna in which a slit is inserted into a part of the conductor plate. One of the slits 3666 is released, and there is a capacitor 362, so that two conductor plates, 360 and 361, and a capacitor The loop antenna is composed of the capacitors 36 3, 36 4 and the capacitor 36 2.

As an example of a wireless device using such an antenna, as shown in Fig. 21, it is possible to consider the case where the arm-mounted type is used. Fig. 27 shows an example of application to a wireless device. There is a conductor plate 371 inside the arm nomad 370. A slit 37 4 is formed along the long side of the conductor plate 37 1. The slit 374 is formed over almost the entire length of the conductor plate 370. The connector 372 has the arm noms 37 0 connected to each other, and the internal conductor plate 37 1 has the capacity of the connector 37 2. They are joined together by 3778, from which they form a loop antenna, both externally and electrically.

A circuit board 375 is provided inside the wireless device main body 373, and a notch from the conductor board 371 extends on the circuit board 375. It has two notches in parallel, with a slit in between. The capacitors 376 and 377 and the high frequency amplification circuit 304 are mounted on the circuit board 375. Also, electrical connection The continuation is the same as the example in Fig. 23.

When this embodiment is applied to a wrist-mounted type wireless device, the pointing characteristics are slightly different from those of the example shown in FIG. In other words, the slot antenna is bent on the loop, which is different from the previous example, but this is how the slot antenna is bent. In all directions along the lit, magnetic field components can be detected. The magnetic field component 38 1 represents this. In addition, the magnetic field component 3832 corresponds to the magnetic field component 3336 in FIG. This is because when viewed from this direction, in each case, it will be seen by a slender loop antenna. These two-way components have a uniform, zero-point characteristic in the directionality and are extremely convenient for portable radios. It has good characteristics.

FIG. 28 is a cross-sectional view illustrating the electrical characteristics of the connector to be attached to the arm in FIG. 27. The arm pad 370 including the conductor plate 371 is tightly connected with the connector 372. The adhered portion has an electric capacity because the conductor plates are overlapped in parallel, and thereby has a loop-up with the conductor plate 371. Configure the antenna.

Fig. 29 is an example of Fig. 27, in which the connector is not used as the electric circuit and the antenna is configured with the arm as the capacity.

A buckle 383 is used in place of the connector 372. By this means, the connector part does not need to consider the electric coupling, but simply means and means for connecting the arm nodes 370 to each other. Become. The conductor plate 371 extends to the middle of the arm band 370. The arm band 370 is connected to the arm 384 of the human body. It has a capacity of 385 between the conductor plate and the conductor plate. The loop antenna is composed of the capacity 385, the arm 3884, and the conductor plate 371. In this embodiment, the magnetic field components 380, 381, and 382 can be detected. Therefore, no matter what direction the arm 3884 is oriented, it is possible to obtain an antenna gain. Although the distribution of the magnetic field distribution on the surface of the human body and arm is not so clear at present, it is useful to use the antenna as disclosed in the present invention. By using this, the magnetic field component on the human body surface can be used, and the improvement in antenna gain can be expected. In addition, the wireless device equipped with the antenna of the present invention can always maintain the stable transmission and reception characteristics of the wireless device.

Claims

The scope of the claims

(1) Loop antenna element, wireless transmission / reception circuit section, data decoder circuit, CPU circuit, data display section, and information In a small portable radio consisting of a circuit section, the loop antenna element described above consists of a first loop antenna and a second loop antenna. A loop shape is formed with the two conductors of the first loop antenna, and one terminal of the first loop antenna is connected to the first variable capacitance element. The other terminal is connected to one terminal of the second variable capacitance element, and the other terminal of the second loop antenna is connected to the second variable capacitance element. An antenna that is connected to the other terminal, and that the other terminal is connected to the high frequency grounding surface on the board.

(2) The high-frequency ground plane has a rectangular surface whose side perpendicular to the loop antenna element is longer than the side along the long side of the loop antenna element. An antenna as set forth in claim 1, characterized in that:

(3) The first and second variable capacitance elements are characterized in that the capacitance value is changed by applying a voltage to both ends of the element. The antenna described in claim 2

(4) One of the combinations of the capacitance ratio of the second variable capacitance element value to the first variable capacitance element value is the second loop antenna. The element described in claim 3 is characterized in that the element is determined to be equal to the element length ratio of the first loop antenna element to the element. Antenna.

(5) The above voltage depends on the attitude of the small portable radio. The antenna of claim 4, wherein the antenna is characterized by a change.

(6) Claims that feature the mounting of a switch that switches the voltage in accordance with the attitude of the small portable radio as described above. 5 listed antennas.

(7) A small portable wireless device characterized by having the antenna described in claim 6 mounted thereon.

(8) A loop antenna element, a wireless transmission / reception circuit section, a data decoder, a CPU circuit, a data display section, and a loop antenna element are provided in the housing. In the case of a small portable radio consisting of a notification circuit, a long circuit board that implements the circuit for operating the small portable radio described above. The direction length is from the transmission / reception wave length of the wireless device.

A loop antenna having an opening area in the direction perpendicular to the long side and between 16 is formed, and the loop antenna is formed. The antenna is characterized in that the length is between 110 and 16 of the transmission / reception wavelength of the wireless device.

(9) In the antenna described in claim 8, the antenna element is such that the total length of the loop antenna element is 6: 1 to 8: 1. And the longer one of each length is the first loop antenna, the shorter one is the second loop antenna, and the first antenna is One terminal of the element is connected to the common potential pattern of the wireless device, and the other terminal is one of the elements of the second antenna. An antenna characterized by being connected to a terminal via a capacitive reactance element.

(10) In the antenna described in claim 8, the length of the circuit board in the longer direction and the length of the loop antenna are almost the same. same — An antenna that is characterized by

(11) In the antenna described in claim 9, the length of the circuit board in the longitudinal direction, the length of the first antenna element, and the length of the second antenna are described. An antenna characterized by the fact that the sum with the element length is almost the same.

(12) A small portable wireless device characterized by incorporating the antenna described in the claim 10 described therein.

(13) A small-sized portable wireless device characterized by incorporating the antenna described in the claim 11 (1).

(14) Inside the enclosure, loop antenna element, wireless transmission / reception circuit, data decoder, CPU circuit, and data display In a small portable radio consisting of a notification circuit, a slit-shaped cutout was installed in a part of the loop antenna described above. An antenna characterized by and.

(15) In the antenna described in Claim 14, the arbitrary points of the two conductor plates sandwiching the above-mentioned cutout part are mutually connected to each other. An antenna characterized by mounting a quantitative reactance element.

(16) In the antenna described in the claim 15, the arbitrary point of one of the two conductor plates sandwiching the cutout portion is defined by the above-mentioned wireless transmission. An antenna characterized in that it is connected to a common potential pattern in the receiving area.

(17) In the antenna described in the claim 16, the optional point of the other of the two conductor plates sandwiching the cut-out section is the above-mentioned solid line. It is characterized by being connected to the high-frequency input terminal of the transmission / reception circuit. The antenna to be used.

(18) In the antenna described in claim 17, the loop antenna element including the J section is a different capacity reactor. An antenna characterized in that it is composed of two pairs of elements, each of which has its own element.

(19) In the antenna described in Claim 18, the capacitive reactance element is located at the center of the cut portion, An antenna characterized in that it is mounted at the opposite position on the loop antenna.

(20) A small portable radio characterized by incorporating the antenna described in claim 19.