WO1999056346A1

WO1999056346A1 - Slot array antenna

Info

Publication number: WO1999056346A1
Application number: PCT/JP1998/001933
Authority: WO
Inventors: Masahito Sato; Yoshihiko Konishi; Moriyasu Miyazaki; Hideyuki Oh-Hashi; Shuji Urasaki
Original assignee: Mitsubishi Denki Kabushiki Kaisha
Priority date: 1998-04-27
Filing date: 1998-04-27
Publication date: 1999-11-04

Abstract

A thin, low-loss, and two-frequency slot array antenna which excites slot elements having different resonance frequencies through a common parallel-plate waveguide and radiates the same linearly polarized wave at different frequencies. The slot array antenna comprises the slot elements having different resonance frequencies and arranged on one conductor plate of the parallel-plate waveguide having short faces at both ends in such a way that the directions of the electric fields of the slot elements are perpendicular to the short faces.

Description

Description Slot antenna Anterior branch

The present invention relates to a slot array antenna in which antennas operating at different frequencies are shared by one antenna aperture. Background art

FIG. 11 is a diagram showing an example of the configuration of a conventional slot array antenna. This is an example shown in Japanese Patent Application Laid-Open No. 63-218104.

In FIG. 11, 1 is a conductor plate, 5 is a slot element resonating at the first frequency formed on the conductor plate 1, and 6 is formed on the conductor plate 1 in an angular relationship orthogonal to the slot element 5. The slot elements resonating at the second frequency thus formed, 28 and 29 are dielectrics formed above and below the conductor plate 1, respectively, and 30 is the first slot element 5 formed on the dielectric 28. Is a microstrip line which excites the second slot element 6 formed on the dielectric material 29, and 32 is a reflector.

Next, the operation will be described. Slot elements 5 and 6 having different resonance frequencies are arranged orthogonally on an intermediate conductor plate 1, and the slot element 5 that resonates at the first frequency is excited by a microstrip line 30. The slot element 6 which resonates at the second frequency is re-excited by the microstrip line 31. Therefore, the microstrip lines 30 and 31 corresponding to the first frequency and the second frequency are divided into the front and back sides of the conductor plate 1, so that there is almost no electrical coupling and different Acts as a slot array antenna that radiates radio waves with polarizations orthogonal to the resonance frequency.

Since a conventional slot array antenna is configured as described above, an orthogonal feed system using a microstrip line is required to excite two types of orthogonal slot elements with different resonance frequencies. There is a problem that the power supply structure becomes complicated.

In addition, since the excitation to the slot element is performed by the microstrip line, there is a problem that the power supply loss increases as the frequency increases.

In addition, since two distribution circuits corresponding to the frequency for distributing power to the microstrip line are formed on the front and back of the conductor plate, for example, this slot array antenna is used as one sub-array. When the array antennas are arranged to form a larger array antenna, there is a problem that the slot element cannot be arranged in the space to the distribution circuit portion of each subarray, and the radiation characteristics of the array antenna deteriorate.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems of the conventional slot antenna, and it has been proposed that the excitation to two types of slot elements having different resonance frequencies be reduced in thickness and to provide a small feed loss. The purpose is to obtain a dual-frequency slot array antenna using a waveguide.

It is also an object to obtain a dual-frequency slot array antenna that emits the same or orthogonal linearly polarized waves at different frequencies, and also radiates the same or opposite circularly polarized waves.

Furthermore, it is another object to obtain a larger slot array antenna for dual frequency use by arranging a plurality of such slot array antennas as one subarray in a linear or arbitrary plane. Disclosure of the invention The slot array antenna according to the present invention is composed of two parallel first and second conductor plates, and an end substantially opposite to the first conductor plate is attached to the second conductor plate. Each of the short surfaces is short-circuited to form a short surface, and the wide wall surface is substantially parallel to the short surface on the second conductor plate and substantially in the middle of the opposing short surface. An oversized waveguide for power supply is connected, and a slot element that resonates on the first conductor plate at a first frequency in a direction in which the electric field direction is orthogonal to the short-circuit plane and a second element at a second frequency. Slot elements that resonate with each other are arranged at intervals of approximately one wavelength from the opposing short surface to the portion where the oversize waveguide for power supply is connected, with reference to the position of approximately half a wavelength, as a reference. And the above slot row Similarly, a plurality of slots are formed in the intersecting direction to form a slot arrangement, and a diplexer having means for separating the first frequency and the second frequency from each other is provided in the power supply oversized waveguide. It is characterized by being connected.

Further, the slot array antenna of the present invention is arranged such that at least one or more slot elements that generally resonate at a lower frequency of the first frequency or the second frequency are rotated around the center thereof as a rotation axis, It is characterized in that the radiation impedance of the slot element is controlled. Further, the slot array antenna of the present invention is configured such that at least one or more slot elements that resonate at a lower frequency of the first frequency or the second frequency are formed as cross-shaped slot elements. The present invention is characterized in that the radiation impedance of the above-mentioned slit element is controlled and the cross polarization component is suppressed.

Further, the slot array antenna of the present invention includes the above-described slot elements such that the directions of the electric fields of the slot element that substantially resonates at the first frequency and the slot element that resonates substantially at the second frequency are substantially orthogonal to each other. Rotate its center It is characterized by being arranged to rotate as an axis.

In the slot array antenna of the present invention, the end face of the connection portion is formed on the second conductor plate and substantially in the center of the opposing short face so that the short face and the wide wall face are substantially parallel to each other. A power supply oversized waveguide having a short surface at a frequency and a power oversize waveguide serving as a short surface at a second frequency are connected substantially adjacent to each other. is there.

Further, the slot array antenna of the present invention has a slot element that resonates substantially at the first frequency and a slot element that resonates generally at the second frequency. From the other short surface, the slots are arranged at an interval of approximately one wavelength based on the position of approximately a half wavelength to form a slot row, and the arrangement of the slot elements that generally resonate at the first frequency described above. A power supply oversize having means for making the end face of the connection portion a short surface at the first frequency so that the short surface and the wide wall surface are substantially parallel to each other on the second conductor plate near the reference short surface. Along with connecting a waveguide, the short surface and the wide wall surface are almost on the second conductor plate near the short surface, which is the reference for the arrangement of the slot elements that generally resonate at the second frequency. Connecting end face so that the line is characterized in that to connect the power supply oversized waveguide having a means comprising a short face at the second frequency.

In addition, the slot array antenna of the present invention includes both a slot element that generally resonates at the first frequency and a slot element that resonates generally at the second frequency, and the short element of one of the opposing short surfaces. Only one half-wavelength position is used as a reference to form a slot array with an interval of approximately one wavelength, and an oversized waveguide for power supply is connected to a short surface that serves as a reference for the arrangement of the slot elements. Above near the other opposing short plane The short surface and the wide wall surface of the oversize waveguide for power supply are connected so as to be substantially parallel to each other.

In addition, the slot array antenna of the present invention includes the above-described slot antenna on a first conductor plate on which a slot element that generally resonates at a first frequency and a slot element that resonates substantially at a second frequency are formed. And a polarizer having means for converting linearly polarized light radiated from the G element into circularly polarized light.

In the slot array antenna of the present invention, N (N is an integer of 2 or more) N slots (N is an integer of 2 or more) are arranged in a straight line or an arbitrary plane as one sub-array. It is characterized in that a feeder circuit comprising at least one of the distribution circuit and at least one of the combining circuits or both is connected.

May of ID side

FIG. 1 is a configuration diagram of a slot antenna according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a slot array antenna according to a second embodiment of the present invention.

FIG. 3 is a configuration diagram of a slot array antenna according to a third embodiment of the present invention.

FIG. 4 is a configuration diagram of a slot array antenna according to a fourth embodiment of the present invention.

FIG. 5 is a configuration diagram of a slot array antenna according to a fifth embodiment of the present invention.

FIG. 6 is a configuration diagram of a slot array antenna according to a sixth embodiment of the present invention. FIG. 7 is a configuration diagram of a slot array antenna according to a seventh embodiment of the present invention.

FIG. 8 is a configuration diagram of a slot array antenna according to an eighth embodiment of the present invention.

FIG. 9 is a configuration diagram of a slot array antenna according to the ninth embodiment of the present invention.

FIG. 10 is a block diagram of a slot array antenna according to Embodiment 9 of the present invention.

FIG. 11 is a configuration diagram showing an example of a conventional slot array antenna. BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1

Hereinafter, a slot antenna according to Embodiment 1 of the present invention will be described with reference to FIG. FIG. 1 is a configuration diagram of a slot array antenna according to an embodiment of the present invention, wherein (a) and (b) show the appearance and cross section, respectively.

In Fig. 1, 1 and 2 are conductor plates parallel to each other, 3 is a dielectric inserted between conductor plate 1 and conductor plate 2, and 4 is a short-circuit between conductor plate 1 and the generally opposite end of conductor plate 2. 5 and 6 are slot elements formed on the conductor plate 1 that resonate at frequencies f1 and f2, respectively. 7 is approximately the middle of the opposing short surface 4 on the conductor plate 2. The oversized waveguide for power supply connected so that the short surface 4 and the wide wall surface are almost parallel to each other, 8 is connected to the oversized waveguide 7 for power supply and separates the frequency f1 from the frequency f2 The diplexers 9 and 10 are feed ports connected to the diplexer 8 for the frequency f1 and the frequency f2, respectively.

Next, the operation of the slot array antenna will be described. frequency The slot element 5, which generally resonates at f1, is connected to the oversize waveguide 7 for power supply sequentially from the two short planes 4 parallel to the Y-axis, each with a position at about a half wavelength (λ 1 Ζ2). Since these parts are arranged at approximately one wavelength interval (λ 1), these slot elements 5 operate as a center-fed resonant planar slot array at the frequency f 1. Similarly, the slot element 6, which generally resonates at the frequency f2, also sequentially feeds the oversized waveguides 7 from the two short planes 4 parallel to the Y-axis with reference to the position of approximately a half wavelength (λ 2 2 2). Since these are arranged at approximately one wavelength interval (λ 2) up to the point where they are connected, these slot elements 6 operate as a center-fed resonant planar slot array at frequency f 2. Excitation to the slot elements 5 and 6 is performed by sharing a parallel plate waveguide composed of the conductor plate 1 and the conductor plate 2 sandwiching the dielectric 3. For this reason, the slot element 5 which resonates substantially at the frequency f1 does not look like a short at the frequency f2 and has some resistance and reactance in the impedance.However, since the values are very small, the resonance element 5 generally resonates at the frequency f2. The effect on the excitation distribution formed by slot 6 is small. The same applies to the case of the reverse frequency relationship. In addition, since both the slot elements 5 and 6 are arranged so that their electric field directions are in the X-axis direction orthogonal to the short plane 4, each of the slot elements 5 and 6 has the same linear polarization. Radiate. Therefore, the excitation to the two types of slot elements 5 and 6 having different resonance frequencies is performed by a thin, parallel plate waveguide with small power loss, and the two frequencies that emit the same linear polarization at different frequencies are used. Acts as a slot array antenna.

In the case of the conventional slot array antenna as shown in Fig. 11, two types of feeding systems with distribution circuits according to the frequency are required to excite two types of slot elements 5 and 6 with different resonance frequencies. In addition, the power supply structure becomes complicated, and each distribution circuit is placed next to the opening face where the slot elements 5 and 6 are arranged. Must be placed, and needless space is required. On the other hand, the slot array antenna according to the present embodiment does not require a distribution circuit according to the frequency, and the two types of slot elements 5 and 6 having different resonance frequencies arranged on the same aperture are combined into one. It can be excited by a parallel plate waveguide. In addition, since the excitation to the slot elements 5 and 6 is performed by a parallel plate waveguide, power can be supplied with a lower loss than when a microstrip line or the like is used. Therefore, the effect of realizing a slot array antenna that is thin, has low loss, and can radiate the same linearly polarized wave at different frequencies can be realized.

Embodiment 2

FIG. 2 is a configuration diagram showing a slot array antenna according to Embodiment 2 of the present invention. The second embodiment has a configuration in which the slot element having the lower resonance frequency in the first embodiment shown in FIG. 1 is rotated around its center as a rotation axis and arranged as a slot element 6a. It is. The sectional configuration of the slot antenna in the second embodiment is the same as that in FIG. 1 (b).

As described above, according to the slot array antenna of this embodiment, two types of slot elements 5 and 6a having different resonance frequencies disposed on the same aperture are formed by one parallel plate waveguide. Since excitation is performed, the power supply circuit for each slot element 5, 6a can be shared, and power can be supplied with lower loss than when using a microstrip line or the like. Furthermore, since the slot element 6a having the lower resonance frequency is rotated around its center as the rotation axis, the radiation impedance of the slot element 6a can be set to an arbitrarily small value depending on the rotation angle. For this reason, the normalized input impedance (the value normalized by the characteristic impedance of the parallel-plate waveguide) as viewed from the oversized waveguide 7 for feeding at the short-circuited surface 4 at both ends is obtained for both the frequency f1 and the frequency f2. Can be set to approximately 2, and the switch in the first embodiment shown in FIG. The reflection characteristic at the lower frequency f2 of the mouth array antenna can be improved. Therefore, rotation of the slot element 6a generates cross polarization components (components in the Y-axis direction), but it emits the same linear polarization at different frequencies and has good reflection characteristics. This has the effect of realizing a slot array antenna that can be shared by two frequencies.

Here, in the slot array antenna according to the second embodiment, all slot elements 6a are rotated about their respective centers as rotation axes, but at least one or more of the many The slot element 6a may be rotated by an arbitrary angle around the center of the slot element as a rotation axis. Further, the rotation angle of each slot element 6a may be set to a different arbitrary rotation angle.

Embodiment 3.

FIG. 3 is a configuration diagram showing a slot array antenna according to Embodiment 3 of the present invention. In the third embodiment, the slot element 6 having the lower resonance frequency in the first embodiment shown in FIG. 1 or the second embodiment shown in FIG. This is the device 6b. The sectional configuration of the slot array antenna according to the third embodiment is the same as that in FIG. 1 (b).

According to the slot array antenna of this embodiment, two types of slot elements 5 and 6b having different resonance frequencies arranged on the same aperture are excited by one parallel plate waveguide. The power supply circuit for the elements 5 and 6b can be shared, and power can be supplied with lower loss than when using a microstrip line or the like. Further, in order to make the slot element 6 having a lower resonance frequency into a cross-shaped slot element 6b having an arbitrary opening angle, the radiation impedance of the wrist slot element 6b is adjusted by adjusting the opening angle. Can be set to any small value. For this reason, oversized waveguide for power supply The input impedance (value normalized by the characteristic impedance of the parallel flat waveguide) when the short side 4 at both ends is viewed from the end can be set to approximately 2 at both the frequency f 1 and the frequency f 2. Thus, the reflection characteristic at the lower frequency f2 of the slot array antenna of the first embodiment shown in FIG. 1 can be improved. Further, since the cross-shaped slot element 6b is used, the cross-polarization component (Y-axis direction component) which is a problem in the slot array antenna according to the second embodiment shown in FIG. 2 can be canceled. Therefore, a slot array antenna that radiates the same linear polarization at different frequencies, has good reflection characteristics, has good cross-polarization characteristics, is thin and has low loss, and is a dual-frequency dual-frequency antenna can be realized. The effect is obtained.

Here, in the slot array antenna according to the third embodiment, all the slot elements 6 are formed as cross-shaped slot elements 6b. At least one or more arbitrary slot elements 6 are formed as cross-shaped slot elements. The element 6b may be used. Further, the opening angles of the cross-shaped slot elements 6b may be set to arbitrary different opening angles.

Embodiment 4.

FIG. 4 is a configuration diagram showing a slot array antenna according to Embodiment 4 of the present invention. In the fourth embodiment, the slot elements 5, 6, 6a, and 6b in the first embodiment shown in FIG. 1 to the third embodiment shown in FIG. 3 are arranged so that their electric field directions are substantially orthogonal to each other. The slot elements 5c and 6c are arranged as inclined elements 5c and 6c. The cross-sectional configuration of the slot array antenna according to the fourth embodiment is the same as that in FIG. 1 (b).

According to the slot array antenna of this embodiment, two types of slot elements 5c and 6c having different resonance frequencies arranged on the same aperture are excited by one parallel plate waveguide. it is possible to share feeding electric circuit for the element 5 c, 6 _C, when due to a microstrip line Power can be supplied with lower loss. Further, since the slot element 5c and the slot element 6c are arranged so that their electric field directions are substantially orthogonal to each other, linearly polarized waves orthogonal to each other can be radiated. In addition, the normalized input impedance (the value normalized by the characteristic impedance of the parallel plate waveguide) when the short-circuited surface 4 on both ends is viewed from the oversize waveguide 7 for power supply is applied to both the frequency f1 and the frequency f2. In general, it can be set to 2, and good reflection characteristics can be obtained at both frequencies. Therefore, it is possible to obtain an effect of realizing a thin, low-loss, dual-frequency slot array antenna that emits linearly polarized waves orthogonal to each other at different frequencies and has good reflection characteristics.

Here, in the slot array antenna according to the fourth embodiment, all the slot elements 5, 6 are slot elements 5c, 6c inclined with respect to the short surface 4, but the slot elements that are not inclined 5 or 6 is fine.

Embodiment 5

FIG. 5 is a configuration diagram showing a slot array antenna according to a fifth embodiment of the present invention, where (a) and (b) show the appearance and cross section, respectively. The fifth embodiment is different from the first embodiment shown in FIG. 1 to the fourth embodiment shown in FIG. 4 in that the oversize waveguide 7 and the diplexer 8 for feeding are replaced on the conductor plate 2 and A power supply over filter provided with a filter 13 so that the end face of the connection part operates as a short at frequency f2 so that the short face 4 and the wide wall are almost parallel to the middle part of the opposing short face 4 The configuration is such that the size waveguide 11 and the power supply oversize waveguide 12 provided with the filter 14 so as to operate as a short circuit at the frequency f1 are connected substantially adjacent to each other.

As described above, according to the slot antenna of this embodiment, two types of slot elements having different resonance frequencies arranged on the same aperture are used. Since the elements 5 and 6 are excited by one parallel-plate waveguide, the power supply circuit for each slot element 5 and 6 can be shared, and power can be supplied with lower loss than when using a microstrip line or the like. Further, when operating at the frequency f1, the connection between the oversized waveguide for power supply 12 and the conductor plate 2 functions as a short by the filter 14, and when operating at the frequency f2, the filter 13 As a result, the connection between the feeding oversized waveguide 11 and the conductor plate 2 acts as a short circuit, so that the slotted antenna of the first embodiment shown in FIG. 1 to the fourth embodiment shown in FIG. Compared to the connection between the power-over waveguide 7 and the conductor plate 2, the connection between the power-over waveguides 11 and 12 and the conductor plate 2 is only in each band. It is sufficient to operate, and the effect that the configuration becomes easy can be obtained.

Embodiment 6

FIG. 6 is a configuration diagram showing a slot antenna according to a sixth embodiment of the present invention. In the sixth embodiment, one of the short surfaces 4 facing the slot element 5 that generally resonates at the frequency f1 and the slot element 6 that resonates generally at the frequency f2 are opposed. From the other short surface 4 to form a slot array by arranging them at intervals of approximately one wavelength (λ 1 and λ 2) based on the positions of approximately half wavelengths (λ 1 Ζ 2 and λ 2 Ζ 2). I have to do it. In addition, the end face of the connection portion has a frequency f1 such that the short face 4 and the wide wall face are substantially parallel to each other on the conductor plate 2 near the short face 4 serving as a reference for the arrangement of the slot elements 5 that generally resonate at the frequency f1. Oversized waveguide for power supply with filter 14a to operate as short circuit at

2 Connect a and connect the short-circuited surface 4 and the wide wall surface on the conductor plate 2 near the short-circuited surface 4 which is the reference for the arrangement of the slot elements 6 that resonate at the frequency f2 so that they are almost parallel. Oversize waveguide for power supply with filter 13a provided so that the end face operates as a short circuit at frequency f2 1 1 a is connected.

According to the slot array antenna of this embodiment, since two types of slot elements 5 and 6 arranged on the same aperture and having different resonance frequencies are excited by one parallel plate waveguide, each slot element 5 And 6 can be shared, and power can be supplied with lower loss than when using a microstrip line or the like. Further, when operating at the frequency f1, the connection between the oversized waveguide for power supply 12a and the conductive plate 2 acts as a short by the filter 14, and when operating at the frequency f2, the filter Since the connection between the oversized waveguide for power supply 11a and the conductor plate 2 acts as a short circuit according to 13, the slot in the embodiment 1 shown in Fig. 1 to the embodiment 4 shown in Fig. 4 Compared to the connection between the feeding oversized waveguide 7 and the conductor plate 2 of the array antenna, the connection between each feeding oversized waveguide 11 and 12 and the conductor plate 2 operates only in each band. This has the effect of simplifying the configuration. Also, as compared with the case of the slot array antenna according to the fifth embodiment shown in FIG. 5, the oversized waveguides 11a and 12a for feeding can be arranged separately, so that they are shown in the figure. However, there is also an effect that connection of the subsequent circuit components to the power supply ports 9 and 10 becomes easy. Embodiment 7

FIG. 7 is a configuration diagram showing a slot antenna according to a seventh embodiment of the present invention. In the seventh embodiment, both the slot element 5 that generally resonates at the frequency f1 and the slot element 6 that resonates generally at the frequency f2 are connected to only one of the short faces 4 of the opposing short faces 4. From the half-wavelength (λ 1 ノ 2 and λ 2 Ζ 2) as a reference so as to form a slot row with a wavelength interval (λ 1 and λ 2). The short surface 4 and the wide wall surface are almost parallel on the conductor plate 2 near the other short surface 4 opposite to the short surface 4 which is the reference of the arrangement of 6. The configuration is such that the power supply oversized waveguide 7a is connected so that

According to the slot antenna of this embodiment, two types of slot elements 5, 6 arranged at the same aperture and having different resonance frequencies are excited by one parallel plate waveguide. And 6 can be shared, and power can be supplied with lower loss than when using a microstrip line or the like. Furthermore, since the oversize waveguide 7a for power supply and the diplexer 8 are configured on one short surface 4, the slot elements 5 and 6 that generally resonate at each frequency are all approximately one wavelength (λ1 and The effect of arranging them at equal intervals at an interval of λ 2) is obtained.

Embodiment 8

FIG. 8 is a configuration diagram showing a slot array antenna according to an eighth embodiment of the present invention. In the eighth embodiment, each of the above-described slot elements 5, 6 is formed on a conductor plate 1 on which a slot element 5 that resonates substantially at frequency f1 and a slot element 6 that resonates substantially at frequency f2 are formed. And a polarizer 15 having means for converting a linearly polarized wave radiated from the optical disk into a circularly polarized wave.

According to the slot array antenna of this embodiment, two types of slot elements 5 and 6 arranged at the same aperture and having different resonance frequencies are excited by one parallel plate waveguide. And 6 can be shared, and power can be supplied with lower loss than when using a microstrip line or the like. Furthermore, a volatilizer 15 (for example, a meander volatilizer) for converting the linearly polarized light radiated from each of the slot elements 5 and 6 into a circularly polarized wave is provided on the conductor plate 1 via a spacer 16. Circularly polarized waves can be radiated together at different frequencies. Therefore, the effect of realizing a thin, low-loss, dual-frequency slot array antenna that radiates circularly polarized waves co-rotating at different frequencies can be realized. Here, in the slot array antenna according to the eighth embodiment, slot element 5 and slot element 6 are both arranged so that their electric field directions are in the X-axis direction perpendicular to short plane 4. The slot element 5 and the slot element 6 may be arranged so that their electric field directions are substantially orthogonal to each other, and may radiate circularly polarized waves having opposite frequencies at different frequencies.

Embodiment 9

FIG. 9 is a configuration diagram illustrating a slot array antenna according to a ninth embodiment of the present invention, and FIG. 10 is a block diagram of the slot array antenna according to the ninth embodiment. In the ninth embodiment, a total of 16 (4 × 4) arrays are arranged from the first embodiment shown in FIG. 1 to the slot array antenna according to the eighth embodiment shown in FIG. 8 as one sub-array. This is a planar slot array antenna. SSPA 22 and LNA 23 are connected to the feed port 9 for frequency f 1 and the feed port 10 for frequency f 2 of each sub-array via BPF 20 and 21 respectively. Are connected to a distribution circuit 24 and a synthesis circuit 25, respectively.

According to the slot array antenna of this embodiment, two types of slot elements 5, 6 arranged at the same aperture and having different resonance frequencies are excited by one parallel plate waveguide. And 6 can be shared, and power can be supplied with lower loss than when using a microstrip line or the like. In addition, this thin, low-loss, dual-frequency slot array antenna is used as one sub-array, and a total of 16 4 × 4 antennas are arranged to form a planar slot array antenna. The effect of realizing a thin and low-loss slot array antenna having a narrow beam and a narrow beam is obtained.

Here, in the slot array antenna according to the ninth embodiment described above, a total of 16 4 × 4 antennas are used as one slot array antenna. Although they are arranged, they may be constituted by arranging N (N is an integer of 2 or more) linearly or in an arbitrary plane.

Further, in the slot array antenna according to the ninth embodiment, one distribution circuit 24 and one combining circuit 25 are connected, but the distribution circuit 24 or the combining circuit is connected to a plurality of sub-arrays. After the connection of the circuit 25, the distribution circuit 24 or the combining circuit 25 may be further connected.

In the slot array antenna according to the ninth embodiment, band-pass filters (BPF) 20 and 21, solid-state power amplifier (SSPA) 22 and low-noise amplifier (LNA) 23 are connected. Alternatively, some or all of these may not be connected.

Further, in the slot array antennas according to Embodiments 1 to 9 described above, frequency f1 is used as the transmission frequency and frequency f2 is used as the reception frequency, but both may be configured as different transmission frequencies or reception frequencies. good. Possible use for cereal II

Since the present invention has the configuration described above, it has the following effects. First, according to the present invention, two types of slot elements having different resonance frequencies are provided on one conductor plate of a parallel plate waveguide composed of two parallel conductor plates, each of which has an electric field direction corresponding to the short plane. A thin, low-loss, dual-frequency slot array antenna that can radiate the same linearly polarized wave at different frequencies is realized because it is arranged orthogonally and excited by a common parallel plate waveguide. The effect that can be obtained is obtained.

Further, according to the present invention, since the slot element having the lower resonance frequency is arranged so as to rotate about the center thereof as a rotation axis, the radiation impedance of the slot element can be set to an arbitrarily small value depending on the rotation angle. , Power supply The normalized input impedance (value normalized by the characteristic impedance of the parallel-plate waveguide) when viewing the short-circuit side at both ends from the bar-size waveguide can be set to approximately 2. Therefore, the effect of improving the reflection characteristics at the lower frequency can be obtained.

Further, according to the present invention, since the cross-shaped slot element is used for the slot element having the lower resonance frequency, the radiation impedance of the re-slot element is adjusted by adjusting the opening angle of the cross portion. Can be set to an arbitrarily small value, and the normalized input impedance (value normalized by the characteristic impedance of the parallel-plate waveguide) when looking at the short-circuit sides at both ends from the oversized waveguide for feeding can be set to approximately 2. It becomes possible. Therefore, the effect of improving the reflection characteristics at the lower frequency can be obtained. Further, since the cross-shaped slot element is used, an effect that the cross polarization component can be canceled can be obtained. Further, according to the present invention, since the slot elements having different resonance frequencies are arranged so that their electric field directions are substantially orthogonal to each other, it is possible to obtain an effect of radiating linearly polarized waves orthogonal to each other. In addition, the normalized input impedance (the value normalized by the characteristic impedance of the parallel plate waveguide) when viewing the short-circuit side of both ends from the oversized waveguide for feeding can be set to approximately 2 at both frequencies. The effect of realizing good reflection characteristics can be obtained. Further, according to the present invention, the oversize waveguides for the power supply for the frequency f2 and the power supply for the frequency f1 which act as short-circuits at the frequencies (f1 and f2) at which the connection portion with the conductor plate is opposed by the filter are provided. Therefore, the connection between each oversized waveguide for power supply and the conductor plate only needs to operate in each band, and the operating band can be narrowed and the configuration is easy compared to the case where two frequencies are shared. Is obtained.

Further, according to the present invention, the oversized waveguides for power supply for the frequency f1 and the frequency f2 are separated and arranged near the short surfaces facing each other. With such a configuration, it is also possible to obtain an effect that the subsequent circuit components can be easily connected to each power supply port.

Also, according to the present invention, since the oversize waveguide for power supply and the diplexer that can be shared at different frequencies are configured on one of the short surfaces, all the slot elements that generally resonate at different frequencies have the same frequency. This has the effect of being able to be arranged at equal intervals at approximately one wavelength interval.

Further, according to the present invention, a volatilizer (for example, a meander volatilizer) for converting linearly polarized light radiated from each slot element into circularly polarized wave is provided on the conductive plate, so that the concentric or reverse rotation is performed at different frequencies. The effect of being able to emit circularly polarized waves is obtained.

Further, according to the present invention, N (N is an integer of 2 or more) linearly or arbitrarily arranged as one subarray of such a thin, low-loss, dual frequency shared slot antenna. Therefore, an effect of realizing a thin and low-loss slot array antenna having higher gain and a narrow beam can be obtained.

Claims

The scope of the claims

1. A short-circuit surface which is composed of two parallel first and second conductor plates, and whose ends substantially opposed to the first conductor plate are short-circuited to the second conductor plate, respectively. To form

A power-supply oversize waveguide is connected to the second conductor plate and to a substantially intermediate portion of the opposing short surface so that its wide wall surface is substantially parallel to the short surface.

The direction of the electric field on the first conductor plate is the second direction of the direction orthogonal to the short surface.

The first slot element that resonates substantially at the frequency of 1 and the second slot element that resonates at the second frequency are supplied with the above-mentioned power supply with reference to the position of about a half wavelength from the opposite short face. The slot where the oversize waveguide is connected is arranged at approximately one wavelength interval up to the point where the oversize waveguide is connected, and a plurality of the above slot rows are also formed in the direction orthogonal to the slot row. Form an array,

A slot array antenna, characterized in that a diplexer having means for separating the first frequency and the second frequency is connected to the oversize waveguide for feeding.

2. The slot array antenna according to claim 1, wherein at least one slot element that resonates substantially at a lower frequency of the first frequency or the second frequency is rotated around its center as a rotation axis. A slot array antenna characterized by controlling the radiation impedance of the slot element.

3. The slot array antenna according to claim 1, wherein the first frequency Alternatively, by making at least one slot element that resonates substantially at the lower frequency of the second frequency into a cross-shaped slot element, the radiation impedance of the slot element is controlled and the cross polarization component is controlled. A slot array antenna characterized by suppressing noise.

4. The slot array antenna according to claim 1, wherein the electric field directions of the slot element that resonates substantially at the first frequency and the slot element that resonates substantially at the second frequency are substantially orthogonal to each other. A slot array antenna, wherein each slot element is arranged so as to rotate about its center as a rotation axis.

5. The slot antenna according to claim 1, wherein instead of the feeder-sized waveguide and the diplexer, the antenna is provided on the second conductor plate and substantially at the center of the opposing short surface. An oversized waveguide for power supply with a means to make the connection end face a short face at the first frequency and a power supply with a short face at the second frequency so that the short face and the wide wall face are almost parallel. A slot array antenna characterized by being connected substantially adjacent to an oversized waveguide.

6. The slot array antenna according to claim 1, wherein a slot element that generally resonates at the first frequency is a slot element that resonates substantially from one of the short surfaces facing the short element and the second frequency. From the other opposing short-circuit surface, the slot elements are arranged at intervals of approximately one wavelength with reference to the position of approximately a half-wavelength each to form a slot array, and furthermore, the resonance occurs at the above first frequency. On the second conductor plate near the short surface, which is the reference for the arrangement of slot elements to be connected, so that the short surface and the wide wall surface are almost parallel A short-circuit plane serving as a reference for the arrangement of slot elements that generally resonates at the second frequency is connected to a power-supply oversize waveguide having means for forming a short-circuit plane at the first frequency. A power supply oversize waveguide having means for making the end face of the connection part a short face at the second frequency is connected to the nearby second conductor plate so that the short face and the wide wall face are substantially parallel to each other. A slot antenna.

7. The slot array antenna according to claim 1, wherein both the slot element that substantially resonates at the first frequency and the slot element that resonates substantially at the second frequency are connected to one of the opposing short surfaces. The slot array is formed by arranging at approximately one wavelength interval based on the position of approximately half a wavelength only from the shot surface to form a slot row, and the oversize waveguide for power supply connected to the second conductor plate is The short surface and the wide wall surface of the oversized waveguide for power supply are connected near the other short surface facing the short surface, which is the reference for the arrangement of the slot elements, so that they are almost parallel to each other. Slot antenna.

8. The slot array antenna according to claim 1, wherein the slot element has a slot element that resonates at a first frequency and a slot element that resonates at a second frequency. A slot array antenna, comprising: a polarizer having means for converting linearly polarized light radiated from each of the slot elements into circularly polarized light.

9. The slot array antenna according to claim 1, wherein the slot array antennas are arranged as N sub-arrays in a linear or arbitrary plane (N is an integer of 2 or more). At least for the sub-array A slot array antenna characterized in that a feeder circuit comprising one or both of one distribution circuit and at least one synthesis circuit is also connected.