JP4243208B2 - Array antenna device - Google Patents

Description

  The present invention relates to an array antenna device that can change the directivity of an array antenna device composed of a plurality of antenna elements, and in particular, adapts the directivity of an electronically controlled waveguide array antenna device (Electronically Steerable Passive Array Radiator Antenna). The present invention relates to an array antenna device that can be changed dynamically.

  Prior art electronically controlled waveguide array antenna devices have been proposed in Non-Patent Document 1 and Patent Document 1, for example. The electronically controlled waveguide array antenna device includes a feeding element to which a radio signal is fed, at least one parasitic element that is provided at a predetermined interval from the feeding element and is not fed with a radio signal, and the parasitic element. A directivity characteristic of the array antenna device can be changed by providing an array antenna including a variable reactance element connected to a feed element and changing a reactance value of the variable reactance element.

  In this electronically controlled waveguide array antenna device, the multi-faceted beam forming capability of this antenna device enables multipath fading and co-channel interference reduction, and enables accurate direction-of-arrival (DOA) estimation of incident signals. To. The antenna device also has applications that maximize wireless computer network and direction finding capabilities.

JP 2001-024431A. JP2003-114268A. T. Ohira et al., "Electronically steerable passive array radiators for low low-cost analog adaptive beamforming", IEEE International Conference on Phased Array Systems and Technology, pp.101-106, Dana Point, U.S.A., May 2000. Y. Ojiro, et al., "Improvement of elevation directivity for ESPAR antennas with finite ground plane", IEEE AP-S Internal Symposium, Boston, U.S.A., July 2001. J.W. Lu, et al., "A performance comparison of smart antenna technology for wireless mobile computing terminals", Proceeding of Asia Pacific Microwave Conference, pp.581-584, Taipei, Taiwan, 3rd-6th December 2001. D.V. Thiel et al., "Switched parasitic antennas for cellular communications", Published by Artech House, pp.170-180, 2002. M. Kominami, et al., "Dipole and slot elements and arrays on semi-infinite substrates", IEEE Transactions on Antennas Propagation, Vol.33, No.6, pp.600-607, June 1994. N. Kishioka et al., "FDTD analysis of strip dipole antenna covered by dielectric material", Proceedings of Asia Pacific Microwave Conference, pp.1352-1355, Sydney, Australia, 3rd-6th December 2000. J.D.Krauss, "Antennas", Published by McGraw-Hill, pp.725-726, 1988. T. Ohira et al., "Handheld microwave direction-of-arrival finder based on varactor tuned aerial beamforming", Proc. Asia Pacific Microwave Conference, pp.585-588, Taipei, Taiwan, 3rd-6th December 2001.

  However, in order to be practical in mobile applications or not to get in the way of its operating environment, miniaturization of this antenna device is a proposition.

  FIG. 12 is a perspective view showing a configuration of an electronically controlled waveguide array antenna device 100A according to a first conventional example disclosed in Non-Patent Document 2, for example. FIG. 12 also shows dimensions in a conventional antenna design in free space.

  In FIG. 12, on the upper end surface of a cylindrical grounding conductor 11A having a so-called skirt portion that has an upper end surface but no lower end surface, there is one feeding element A0 and a predetermined centering on the feeding element A0. The six parasitic elements A1 to A6 are planted on the circumference separated by a distance of 2 mm so as to be perpendicular to and parallel to the upper end face of the ground conductor 11A. Here, the power feeding element A0 is supported so that the lower end portion is electrically insulated from the ground conductor 11A, and the lower end portion is connected to the wireless device via the power feeding cable. The parasitic elements A1 to A6 are supported such that the lower ends thereof are electrically insulated from the ground conductor 11A, and the lower ends of the parasitic elements A1 to A6 are grounded via variable reactance elements. ing.

0.25λ as in ESPAR antenna 100A configured as described above, the length of each element A0 through A6 can resonate at a desired frequency (the wavelength of the frequency and lambda _0.) Slightly shorter than _zero . A conductive skirt (cylindrical peripheral portion) is used for the ground conductor 11A so as to reduce the elevation angle of the radiation pattern of the main lobe and at the same time reduce the cylindrical radius of the ground conductor 11A (see Non-Patent Document 2).

  By the way, a method for miniaturizing an array antenna device by embedding a monopole electronically controlled waveguide array antenna device in a solid cylindrical dielectric has already been disclosed in Non-Patent Document 3, for example. For example, when the array antenna device is completely embedded in a dielectric having a higher dielectric constant than that in free space, the size of the array antenna device can be reduced according to the following equation (1).

Here, λ _r is the wavelength of electromagnetic energy propagating infinitely in the lossless material, λ ₀ is the wavelength of free space, and μ _r and ε _r are the relative permeability and relative permittivity of the material, respectively. .

  FIG. 13 is a perspective view showing a configuration of an electronically controlled waveguide array antenna device 100B according to a second conventional example disclosed in Non-Patent Document 4-6, for example. FIG. 13 also shows the dimensions of the array antenna device using the above-described size reduction method.

In FIG. 13, a feeding element A0 and parasitic elements A1 to A6 are arranged on a disk-shaped ground conductor 11B. Here, the size of the array antenna apparatus 100B can be reduced by attaching an inner radius of the cylindrical dielectric 13B to 0.25 [lambda _r, parasitic elements A1 through A6 in a position on the circumference of the inner radius . New length of the parasitic element A1 to A6 of the formula (1) Average and is effective dielectric constant term of the dielectric constant and permittivity of free space medium of epsilon _r term dielectric 13B of Equation 1]
ε _e = (ε ₀ + ε _r ) / 2
Can be approximated by substituting with (see Non-Patent Documents 4-6).

  As described above, in the conventional example, in the array antenna apparatus, the collar portion of the skirt is still large, and further downsizing is desired.

  An object of the present invention is to solve the above problems and provide an array antenna apparatus that can be further reduced in size as compared with the prior art.

An array antenna apparatus according to the present invention includes a feed element for transmitting and receiving a radio signal, at least one parasitic element provided at a predetermined distance from the feed element, and a variable connected to the parasitic element. In an array antenna apparatus, comprising a reactance element, and changing the reactance value of the variable reactance element to operate the parasitic element as a director or a reflector, respectively, and changing a directivity characteristic of the array antenna apparatus.
A columnar dielectric having a diameter substantially the same as the diameter of the cylinder of the ground conductor is arranged on the upper end face of the grounded conductor having a cylindrical shape having at least an upper end surface so that their central axes coincide with each other. The feeding element is arranged in the dielectric, and the parasitic element is arranged on the outer peripheral surface of the dielectric.

  In the array antenna device, preferably, the dielectric has a substantially cylindrical shape, a substantially elliptical shape, or a polygonal columnar shape.

  According to the array antenna apparatus of the present invention, the radius can be made substantially equal to the radius of the ground conductor as compared with the array antenna apparatus of the prior art, thereby reducing the size of the entire array antenna apparatus. Significantly smaller and smaller.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected about the same component.

<First Embodiment>
FIG. 1 is a perspective view showing a configuration of an array antenna apparatus 100C according to the first embodiment of the present invention, and FIG. 2 is a block diagram showing a configuration of an array antenna control apparatus using the array antenna apparatus 100C of FIG. is there.

  The array antenna apparatus 100C according to the first embodiment includes a feeding element A0 for transmitting and receiving radio signals, six parasitic elements A1-A6 provided at a predetermined distance from the feeding element, Six variable reactance elements 12-1 to 12-6 connected to the feed elements A1-A6, respectively, and changing the reactance values of the parasitic elements A1-A6 to the waveguide or the reflection, respectively. This is an electronically controlled waveguide array antenna device that operates as a detector and changes the directivity characteristics of the array antenna device. Here, on the upper end surface of the hollow cylindrical grounding conductor 11C having at least the upper end surface, a dielectric 13C having a columnar shape having a radius substantially the same as the radius of the cylinder of the grounding conductor 11C is placed on the center axis thereof. Are arranged such that they coincide with each other, the feeding element A0 is arranged in the dielectric 13C, and the parasitic elements A1-A6 are arranged on the outer peripheral surface of the dielectric 13C.

1 and 2, on the upper end surface of a cylindrical ground conductor 11C having a length h _s and a radius r _dg , a radius having a length h _{dp made} of alumina (relative permittivity ε _r = 9.6), for example. the dielectric 13C of cylindrical shape r _dg is arranged so that their central axes coincide, for example, be fixed using a predetermined adhesive. A monopole feed element A0 having _a length ha on the central axis of the dielectric 13C is provided embedded in the dielectric 13C so as to be disposed along the central axis. The lower end portion of the power feeding element A0 serves as a power feeding point, and is connected to a wireless device including the wireless transmitter 7 through the coaxial cable 5 for power feeding. The parasitic elements A1 to A6 have the same length _hdp as the dielectric, and are arranged at equal intervals on the outer peripheral surface of the dielectric 13C.

  In FIG. 2, the feeding point of the feeding element A0 is connected to the low noise amplifier (LNA) 1 through the feeding coaxial cable 5 and the circulator 6, and the parasitic elements A1 to A6 are respectively variable reactance elements 12-1. To 12-6, and these variable reactance elements 12-1 to 12-6 change their reactance values in response to a control voltage signal from the adaptive control type controller 20.

  1 and 2, the lower end portion of the feeding element A0 is electrically insulated from the ground conductor 11, and the parasitic elements A1 to A6 are respectively connected to the ground conductor via the variable reactance elements 12-1 to 12-6. 11 is grounded at high frequency. The operation of the variable reactance elements 12-1 to 12-6 will be described. For example, when the longitudinal lengths of the feed element A0 and the parasitic elements A1 to A6 are substantially the same, for example, the variable reactance element 12-1 Is inductive (L property), the variable reactance element 12-1 becomes an extension coil, and the electric length of the parasitic element A1 is longer than that of the feeder element A0, and functions as a reflector. On the other hand, for example, when the variable reactance element 12-1 has capacitance (C-type), the variable reactance element 12-1 becomes a shortening capacitor, and the electrical length of the parasitic element A1 is shorter than that of the feeder element A0. Acts as a director. The parasitic elements A2 to A6 connected to the other variable reactance elements 12-2 to 12-6 operate in the same manner.

  Therefore, in the array antenna apparatus 100C of FIG. 2, the control voltage value applied to the variable reactance elements 12-1 to 12-6 connected to the parasitic elements A1 to A6 is changed, and the reactance that is the junction capacitance value is changed. By changing the value, the plane directivity of the array antenna apparatus 100C can be changed.

  In the array antenna control apparatus of FIG. 2, a transmitting station that transmits a radio signal received by the array antenna 100 </ b> C has a learning sequence having the same signal pattern as a predetermined learning sequence signal generated by the learning sequence signal generator 21. In accordance with a digital data signal of a predetermined symbol rate including the signal, a radio frequency carrier signal is modulated using a digital modulation method such as BPSK or QPSK, and the modulated signal is power-amplified to receive array antenna apparatus 100C of the receiving station. Send to. In this embodiment, before performing data communication, a radio signal including a learning sequence signal is transmitted from the transmitting station to the receiving station, and adaptive control processing by the adaptive control type controller 20 is executed at the receiving station.

  The array antenna apparatus 100C receives a radio signal from the transmitting station, and the received signal is input to the low noise amplifier (LNA) 1 through the feeding coaxial cable 5 and the circulator 6 and amplified, and then down The converter (D / C) 2 performs low-frequency conversion of the amplified signal into a signal having a predetermined intermediate frequency (IF signal). Further, the A / D converter 3 A / D converts the low-frequency converted analog signal into a digital signal, and outputs the digital signal to the adaptive control controller 20 and the demodulator 4. Next, the adaptive control controller 20 sequentially perturbs the reactance values of the variable reactance elements by a predetermined difference width based on the received reception signal and the learning sequence signal, and performs a predetermined evaluation on each reactance value. A function value (for example, received signal power) is calculated, and each reactance value is repeated using the steepest gradient method based on the calculated evaluation function value so that the evaluation function value is maximized. Thus, the reactance value of each variable reactance element for directing the main beam of the array antenna apparatus 100C toward the desired wave and the null toward the interference wave is calculated and set. Thus, the bias voltage value of each variable reactance element for directing the main beam of the array antenna apparatus 100C in the direction of the desired wave and the null in the direction of the interference wave is searched so that the evaluation function value becomes maximum. Then, a control voltage signal having each searched bias voltage value is output to each variable reactance element and set.

  As described above, in the array antenna device 100C according to the present embodiment, the ground conductor 11C is also reduced so as to have a radius that coincides with the arrangement radius of the cylindrical dielectric 13C and the parasitic elements A1-A6. The size can be reduced compared to the conventional example. The dielectric 13C is not limited to a cylindrical shape, and may be a columnar shape such as a substantially cylindrical shape, a substantially elliptical columnar shape, or a substantially polygonal columnar shape.

  In the above embodiment, the hollow cylindrical grounding conductor 11C is used. However, the present invention is not limited to this, and a cylindrical grounding conductor such as a hollow general cylindrical shape or a substantially elliptical cylindrical shape, or a medium It may be a ground conductor having a columnar shape such as a real cylindrical shape, a substantially cylindrical shape, or a substantially elliptical columnar shape.

<Second Embodiment>
FIG. 3 is a perspective view showing a configuration of an array antenna apparatus 100D according to the second embodiment of the present invention, and FIG. 4 is a top view showing an upper surface of the array antenna apparatus 100D of FIG. FIG. 5 is a detailed front view showing a configuration in the vicinity of the lower portion of the parasitic element A1 of the array antenna apparatus 100D of FIG. Compared to the array antenna device 100C of FIG. 1 provided with a cylindrical dielectric 13C, the array antenna device 100D according to the present embodiment includes a 12-sided prism-shaped dielectric 13D, and 12 outer circumferences of the dielectric 13D. It is characterized in that strip-shaped parasitic elements A1-A6 are formed on every other outer peripheral rectangular surface of the rectangular surfaces. Hereinafter, a detailed description will be given focusing on differences from the first embodiment.

3, the length _h on the upper end surface of the ground conductor 11D of cylindrical radius _{r dg} in _s, for example, polycarbonate carbonate (dielectric constant epsilon _r = 2.9) radius length _{h d} comprising at _{r dg} These dodecagonal prism-shaped dielectrics 13D are arranged so that their central axes coincide with each other, and are fixed using, for example, a predetermined adhesive. A monopole feed element A0 having _a length ha on the central axis of the dielectric 13D is provided embedded in the dielectric 13D so as to be disposed along the central axis. The lower end portion of the power feeding element A0 serves as a power feeding point, and is connected to a wireless device including the wireless transmitter 7 through the coaxial cable 5 for power feeding. Each parasitic element A1 to A6 has a length h _p, respectively every the outer peripheral rectangular surface of the twelve outer peripheral rectangular surface of the dielectric 13D of the dielectric 13D, a predetermined equal intervals In this way, the strip-shaped parasitic elements A1-A6 were formed so that the longitudinal direction thereof was parallel to the central axis. As shown in the top view of FIG. 4, each of the parasitic elements A1 to A6 has a conductor pattern 51 formed on the Teflon substrate 50, and is in contact with the inner surface of the 12-sided prism shape of the dielectric 13D. The radius of the inner circumference circle is _rdg .

  Terminal conductors 61 and 62 are formed on the Teflon substrate 50 below the lower end portion of the conductor pattern 51 of the parasitic element A1 in FIG. 5, where the terminal conductor 62 is screwed to the ground conductor 11D with a screw 63. The The conductor pattern 51 is connected to the terminal conductor 61 via a resistor R1, and is connected to the terminal conductor 62 via a variable reactance element 12-1, which is a variable capacitance diode, for example. The terminal conductor 61 is connected to the terminal conductor 62 through resistors R2 and R3. Further, the terminal conductor 61 is connected to the ground conductor 11D via a through-hole conductor 41 filled in a through-hole penetrating the Teflon substrate 50 in the thickness direction. The terminal conductor 62 is connected to the ground conductor 11D via a plurality of through-hole conductors 42 filled in through-holes that penetrate the Teflon substrate 50 in the thickness direction.

  As described above, in the array antenna device 100D according to the present embodiment, the ground conductor 11D also has a radius that matches the inner radius of the dodecagonal dielectric 13D and the arrangement radius of the parasitic elements A1-A6. Thus, the size can be reduced as compared with the conventional example.

  In the above embodiment, the hollow cylindrical grounding conductor 11D is used. However, the present invention is not limited to this, and a cylindrical grounding conductor such as a hollow general cylindrical shape or a substantially elliptical cylindrical shape, or a medium It may be a ground conductor having a columnar shape such as a real cylindrical shape, a substantially cylindrical shape, or a substantially elliptical columnar shape.

  In the above embodiment, the 12-prism-shaped dielectric 13D is used, but the present invention is not limited to this, and a polygonal-shaped dielectric according to the number of parasitic elements may be used.

<Modification>
In the above embodiment, the six parasitic elements A1 to A6 are provided. However, the present invention is not limited to this, and the directivity characteristics of the array antenna apparatus can be changed by including at least one parasitic element. You may let them.

  Next, simulation results of the array antenna device 100C according to the first embodiment and the array antenna device 100D according to the second embodiment will be described below.

In array antenna apparatus 100C according to the first embodiment, the structure of array antenna apparatus 100C is simulated using a high frequency structure simulator (HFSS: High Frequency Structure Simulator) manufactured by Ansoft, and multi-niche crowding is employed. And optimized for structural parameters and reactance value sets (x ₁ , x ₂ , x ₃ , x ₄ , x ₅ , x ₆ ). Here, the structure of the array antenna apparatus 100C is optimized with respect to an arrival azimuth angle search application that does not use adaptive beamforming so that a constant reactance value cannot be used. For example, the calculation of arrival azimuths up to 30 ° can be done by measuring the signal strength received at discrete beam positions at azimuths separated by 30 °, thereby providing an array of electronically controlled waveguide array antenna devices. This can be achieved using the antenna device 100C. Beam steering is achieved by changing the reactance value set using adaptively loaded parasitic elements A1-A6. An angle of arrival specification of 30 ° apart is achieved when the main lobe half-power beamwidth is 90 ° or less.

In the present embodiment, the material used for the cylindrical dielectric 13C is alumina having a relative dielectric constant ε _r of 9.5 and a loss tangent of 0.015. The optimization cost function was set so that the directivity gain of the main beam in the direction of the parasitic element A1 was maximized with respect to the half-value power width (azimuth angle) of 90 °. Since the feeding element A0 is connected to the wireless device via the impedance matching circuit, the return loss is not considered. The simulation frequency was set to 2.484 GHz.

In the simulation result of the present inventors, the optimized range of the height _{h dp} dielectric 13C and the parasitic element A1-A6 was 0.25 [lambda _r to 0.25 [lambda _0. The cylindrical radius r _dg of the cylindrical dielectric 13C and the ground conductor 11C was changed between 0.23λ _r and 0.33λ _r . The optimization includes a base reactance value set of the parasitic elements A1 to A6, and the optimization range of the reactance values x ₁ , x ₂ , x _3, and x ₄ is −90Ω to −5Ω, which is the first embodiment. Using the symmetry of the electronically controlled waveguide array antenna device according to the above, the number of optimization variables was reduced to x ₅ = x ₃ and x ₆ = x ₂ . Each length _{h s} of the height _{h a} and the ground conductor 11C of the feed element A0 was kept constant at 9.8mm and 30.2 mm. The width of the parasitic elements A1 to A6 was 1.8 mm, and the radius of the feeder elements was 0.5 mm.

  Table 1 below shows the optimum design parameters of the simulated array antenna apparatus 100C.

  The array antenna device 100C according to the first embodiment has a radius reduced by 79% and a height reduced by 18% compared to the first conventional electronically controlled waveguide array antenna device 100A arranged in free space. At the same frequency, the size (volume ratio) was effectively 1/33.

  6 is a simulation result of the array antenna apparatus 100C of FIG. 1 and shows the directivity characteristics of the H plane. FIG. 7 is a simulation result of the array antenna apparatus 100C of FIG. FIG. As is apparent from FIGS. 6 and 7, a directivity gain of 4.83 dB can be obtained with a half-value power width of 90 °.

  Also in the array antenna device 100D according to the second embodiment, the structure of the array antenna device 100D is simulated using a high-frequency electromagnetic field structure simulator (HFSS) manufactured by Ansoft, as in the first embodiment. A predetermined genetic algorithm employing niche crowding was used to optimize for structural parameters and reactance value sets.

The dielectric 13D used in the second embodiment is made of polycarbonate, and as for its electrical characteristics, the relative dielectric constant ε _r is 2.9 and the loss tangent is 0.006. By using the array antenna device 100D according to the second embodiment, the parasitic elements A1-A6 configured using the Teflon substrate 50 that is a printed circuit board can be formed flat with respect to the dielectric 13D. Here, the inventors optimized the array antenna apparatus 100D so that the gain in the direction of the parasitic element A1 is maximized and the half-value power width of less than 90 ° at a frequency of 2.484 GHz.

In the simulation of the present inventors, the optimized range of the height _{h p} of the parasitic element A1-A6 was 0.282Ramuda _r to 0.381λ _r. The width of the parasitic element A1-A6 is constant at 6 mm, the height _{h d} of the dielectric 13D is always longer by 7mm than the length _{h p} of the parasitic element A1-A6. Feed element A0 has a radius of 1 mm, and optimize the height _{h a} between 0.226Ramuda _r to 0.247λ _r. Inner radius _{r dg} radius and dielectric 13D of the ground conductor 11D was optimized between 0.211Ramuda _r to 0.31λ _r. The length _{h s} of the ground conductor 11D is not optimized variable was set to 0.25 [lambda _0. The reactance values x ₁ -x ₆ of the variable reactance elements 12-1 to 12-6 loaded on the parasitic elements A1-A6 were changed from -73Ω to 14Ω. In this case as well, the number of reactance optimization variables was reduced using symmetry as described above.

  Table 2 below shows the optimum design parameters of the simulated array antenna apparatus 100D.

  According to the optimum design parameters, an absolute gain of 2.8 dBi and a half-value power width of 76 ° at a frequency of 2.484 GHz were obtained. In the second embodiment, the radius is reduced by 69% and the height is reduced by 6% as compared with the first conventional electronically controlled waveguide array antenna apparatus arranged in free space. Ratio) was almost 1/11.

  FIG. 8 is a simulation result of the array antenna apparatus 100D of FIG. 3 and shows the directivity characteristics of the H plane. FIG. 9 is a simulation result of the array antenna apparatus 100D of FIG. FIG. 8 and 9 show normalized radiation patterns on the H and E planes. Remcom's electromagnetic field simulation software “XFDTD” (FDTD (Finite Difference), one of the standard methods of electromagnetic field analysis, is currently used. The simulation result of the second embodiment was verified using 3D electromagnetic field simulation software using Time Domain (time domain difference method). In the simulation by XFDTD, the gain and the half-value power width were calculated as 3.91 dBi and 68 °, respectively. This was superior to the results calculated using HFSS.

  FIG. 10 shows the experimental results of the array antenna apparatus 100D of FIG. 3, and shows the directivity characteristics of the H plane (when the main beam azimuth is 0, 60, 120, 180, 240, and 300 degrees). FIG. 11 is an experimental result of the array antenna apparatus 100D of FIG. 3, and shows the directivity characteristics of the H plane (when the main beam azimuth is 30, 90, 150, 210, 270, and 330 degrees). is there. As is apparent from FIGS. 10 and 11, it can be seen that the simulation results of FIG. 10 and 11, the maximum gain at the azimuth angle of the main beam is added.

  As described above, according to the embodiment of the present invention, the feed element A0 is embedded in the solid dielectric 13C or 13D, and the parasitic elements A1-A6 are formed on the outer peripheral surface thereof. The electronically controlled waveguide array antenna device can be greatly reduced in size.

It is a perspective view which shows the structure of the array antenna apparatus 100C which concerns on the 1st Embodiment of this invention. It is a block diagram which shows the structure of the control apparatus of the array antenna using the array antenna apparatus 100C of FIG. It is a perspective view which shows the structure of array antenna apparatus 100D which concerns on the 2nd Embodiment of this invention. FIG. 4 is a top view showing the top surface of array antenna device 100D of FIG. 3. FIG. 4 is a detailed front view showing a configuration near a lower portion of a parasitic element A1 of the array antenna apparatus 100D of FIG. 3. It is a simulation result of the array antenna apparatus 100C of FIG. 1, and is a diagram showing the directivity characteristics of the H plane. It is a simulation result of the array antenna apparatus 100C of FIG. 1, and is a diagram showing the directivity characteristics of the E plane. It is a simulation result of array antenna apparatus 100D of FIG. 3, Comprising: It is a figure which shows the directional characteristic of H surface. It is a simulation result of array antenna apparatus 100D of FIG. 3, Comprising: It is a figure which shows the directional characteristic of E surface. It is an experimental result of array antenna apparatus 100D of FIG. 3, Comprising: It is a figure which shows the directivity characteristic (When the azimuth angle of a main beam is 0, 60, 120, 180, 240, 300 degree | times) of H surface. It is an experimental result of array antenna apparatus 100D of FIG. 3, Comprising: It is a figure which shows the directivity characteristic (when the azimuth angle of a main beam is 30, 90, 150, 210, 270, 330 degrees) of H surface. It is a perspective view which shows the structure of the electronic control waveguide array antenna apparatus 100A which concerns on a 1st prior art example. It is a perspective view which shows the structure of the electronically controlled waveguide array antenna apparatus 100B which concerns on a 2nd prior art example.

Explanation of symbols

A0: Feeding element,
A1 to A6 ... parasitic element,
R1, R2, R3 ... resistance,
1 ... Low noise amplifier (LNA),
2 ... down converter,
3 ... A / D converter,
5 ... Coaxial cable for feeding,
6 ... circulator,
7 ... Wireless receiver,
11C, 11D ... grounding conductor,
12-1 to 12-6 ... variable reactance element,
13A, 13B, 13C, 13D ... dielectric,
20 ... Controller,
21 ... CRT display
41, 42 ... through-hole conductors,
50 ... Teflon substrate,
51 ... Conductor pattern,
61, 62 ... terminal conductors,
63 ... screw,
100A, 100B, 100C, 100D ... array antenna device.

Claims (2)

A feed element for transmitting and receiving a radio signal; at least one parasitic element provided at a predetermined distance from the feed element; and a variable reactance element connected to the parasitic element, the variable reactance By changing the reactance value of the element, the parasitic element is operated as a director or a reflector, respectively, and in the array antenna apparatus that changes the directivity characteristics of the array antenna apparatus,
On the upper end surface of the ground conductor having a circular cylindrical shape having an upper surface at least, so that the dielectric having a circular column shape having a diameter size substantially the same in the cylinder of the ground conductor their center axes coincide Arranged in the dielectric body, the parasitic element is disposed on the outer peripheral surface of the dielectric ,
When the free space wavelength of the frequency of the radio signal is λo and the wavelength of the radio signal propagating in the dielectric is λr,
(1) Set the cylindrical height (h _s ) of the ground conductor to 0.25λo,
(2) The columnar height (h _dp ) of the dielectric is set in the range of 0.25λr to 0.25λo,
(3) An array antenna device characterized in that the volume ratio of the antenna device is reduced by setting the columnar radius (r _dg ) of the dielectric within a range of 0.23λr to 0.33λr . The array antenna apparatus according to claim 1, wherein the array antenna apparatus includes six parasitic elements.

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