JP7317599B2 - antenna device - Google Patents

Description

An embodiment of the present invention relates to an antenna device that handles high frequency signals.

An electronic scanning antenna is known that scans a directional beam using an array antenna. Further, there is known an antenna device using digital beamforming (DBF) in which each antenna element is weighted by digital signal processing.

In such an antenna device, a plurality of distributors for distributing received signals received by the plurality of antenna elements included in the array antenna, and a receiver for obtaining a received signal of a desired signal level by synthesizing the distributed received signals. are used.

Also, an array antenna is used in which the number of combined antenna elements is larger in the central portion than in the peripheral portion. In this case, more dividers and combiners are required to generate a plurality of combined outputs according to the number of antenna elements in the peripheral portion and the central portion.

As the number of splitters and combiners increases, so does the number of radio frequency (RF) cables connecting them. Also, a device for switching between multiple combined outputs is required. This increases the circuit area of the antenna device.

JP 2017-79434 A

A problem to be solved by the present invention is to provide an antenna device capable of improving performance and miniaturizing.

An antenna device according to an embodiment includes a plurality of antenna element groups arranged along a first direction, and the plurality of antenna element groups are a first antenna element group arranged in a central portion and a peripheral portion. each of the plurality of antenna element groups includes a plurality of antenna elements arranged in a second direction intersecting the first direction, and the number of antenna elements in the first antenna element group is connected to an array antenna, which is larger than the number of antenna elements in the second antenna element group, and to a plurality of antenna elements included in the first antenna element group, and a plurality of first transmission/reception devices for amplifying transmission signals and reception signals; a plurality of second transmission/reception modules each connected to a plurality of antenna elements included in the second antenna element group and amplifying transmission signals and reception signals; and a plurality of transmission/reception modules output from the first transmission/reception modules. a first combiner for combining first received signals to generate a first combined signal; and a second combiner for combining a plurality of second received signals output from the plurality of second transceiver modules to generate a second combined signal. 2 combiners. Each of the plurality of first transceiver modules includes an amplifier for received signals and an attenuator connected to an input of the amplifier. The attenuator changes an amount of attenuation according to a gain difference between a combined gain of the first combined signal and a combined gain of the second combined signal.

FIG. 1 is a block diagram of an antenna device according to an embodiment. FIG. 2 is a schematic diagram explaining the layout of the array antenna shown in FIG. FIG. 3 is a schematic diagram for explaining the layout of the antenna element group. FIG. 4 is a block diagram of a divider/combiner corresponding to the AC train antenna element group shown in FIG. FIG. 5 is a block diagram of a divider/combiner corresponding to the BC array antenna element group shown in FIG. FIG. 6 is a block diagram of the transceiver module shown in FIG. FIG. 7 is a circuit diagram of the attenuator shown in FIG. FIG. 8 is a graph explaining the insertion loss when the attenuator is open. FIG. 9 is a graph explaining the insertion loss when the attenuator is short-circuited. FIG. 10 is a schematic diagram explaining the layout of an array antenna according to a comparative example. FIG. 11 is a block diagram of a divider/combiner corresponding to an AC train antenna element group according to a comparative example. FIG. 12 is a block diagram of a divider-combiner corresponding to a BC-sequence antenna element group according to a comparative example. FIG. 13 is a block diagram of a transmission/reception module according to a comparative example.

Hereinafter, embodiments will be described with reference to the drawings. In the following description, elements having the same functions and configurations are denoted by the same reference numerals, and redundant description will be given only when necessary.

[1] Configuration of Antenna Device FIG. 1 is a block diagram of an antenna device 1 according to an embodiment. The antenna device 1 is an electronic scanning antenna that can use digital beamforming (DBF) technology.

The antenna device 1 includes an array antenna 10 , a plurality of transmission/reception modules 12 , a divider/combiner 13 , a control circuit 14 , a transmitter 15 and a receiver 16 .

The array antenna 10 consists of a phased array antenna. The array antenna 10 has a plurality of antenna elements 11 arranged two-dimensionally. The array antenna 10 transmits and receives radio frequency signals (also called RF signals).

A plurality of transmitting/receiving modules 12 are connected to a plurality of antenna elements 11 respectively. The transmission/reception module 12 performs phase conversion and amplification of high frequency signals.

The distributor/synthesizer 13 distributes and synthesizes high-frequency signals. The distributor/combiner 13 includes a plurality of distributors and a plurality of combiners. Further, the distributor/combiner 13 includes a circulator that switches paths between the transmission signal and the reception signal.

The control circuit 14 controls operations of the transmission/reception module 12 and the divider/synthesizer 13 .

Transmitter 15 is a device that generates a transmission signal to be transmitted from antenna element 11 . The transmitter 15 generates a transmission signal and outputs it to the distributor/combiner 13 .

The receiver 16 is a device that performs signal processing on the high-frequency signal obtained from the distributor/combiner 13 to generate a received signal. The receiver 16 outputs the generated received signal to a subsequent circuit (not shown).

FIG. 2 is a schematic diagram for explaining the layout of the array antenna 10 shown in FIG.

The array antenna 10 includes a plurality of antenna elements 11 arranged in the X direction and the Y direction orthogonal to the X direction. Circles shown in FIG. 2 represent the antenna elements 11 . The X direction corresponds to the AZ (azimuth) direction. The Y direction corresponds to the EL (elevation) direction. FIG. 2 shows a configuration in which the array antenna 10 includes ten antenna elements 11 as an example. The number of antenna elements 11 included in the array antenna 10 can be set arbitrarily.

Array antenna 10 has a cross shape as a whole. That is, when viewed along the X direction, the number of antenna elements in the central portion is greater than the number of antenna elements in the peripheral portion. Similarly, when viewed along the Y direction, the number of antenna elements in the central portion is greater than the number of antenna elements in the peripheral portion.

A plurality of antenna elements 11 are distinguished by branch numbers attached to reference numerals. Branch number MN corresponds to row number M and column number N. In the description of the present embodiment, when distinguishing a plurality of elements to which the same reference numerals are attached, branch numbers are attached to the reference numerals. Descriptions relating to reference numerals without branch numbers are common to a plurality of elements to which the same reference numerals are attached.

The antenna element group in the first row (the top row of the drawing) consists of antenna elements 11-12 and 11-13. The second row antenna element group consists of antenna elements 11-21, 11-22, 11-23 and 11-24. The third row antenna element group consists of antenna elements 11-31, 11-32, 11-33, and 11-34. The fourth row antenna element group consists of antenna elements 11-42 and 11-43. The antenna element group in the first column (the leftmost column in the drawing) consists of antenna elements 11-21 and 11-31. The group of antenna elements in the second row consists of antenna elements 11-12, 11-22, 11-32 and 11-42. The third row antenna element group consists of antenna elements 11-13, 11-23, 11-33, and 11-43. The fourth row antenna element group consists of antenna elements 11-24 and 11-34.

When viewed along the X direction, the antenna element group consisting of the antenna elements 11-12 and 11-13 and the antenna element group consisting of the antenna elements 11-42 and 11-43 are the peripheral antenna element group. , an antenna element group consisting of antenna elements 11-21, 11-22, 11-23, and 11-24, and an antenna element group consisting of antenna elements 11-31, 11-32, 11-33, and 11-34, This is the group of antenna elements in the central part.

When viewed along the Y direction, the antenna element group consisting of the antenna elements 11-21 and 11-31 and the antenna element group consisting of the antenna elements 11-24 and 11-34 are the peripheral antenna element group. , an antenna element group consisting of antenna elements 11-12, 11-22, 11-32, and 11-42, and an antenna element group consisting of antenna elements 11-13, 11-23, 11-33, and 11-43, This is the group of antenna elements in the central part.

[2] Configuration of Divider/Combiner 13 Next, the configuration of the divider/combiner 13 will be described. Below, the configuration of a part of the divider/combiner 13 corresponding to the antenna element group of the AC column (consisting of A column and C row) shown in FIG. 3 and the BC column (B column and C row) shown in FIG. ) will be extracted and explained.

FIG. 4 is a block diagram of the divider/combiner 13 corresponding to the AC train antenna element group shown in FIG.

The row A antenna element group shown in FIG. 4 consists of antenna elements 11-13, 11-23, 11-33, and 11-43. The row C antenna element group shown in FIG. 4 consists of antenna elements 11-31, 11-32, 11-33, and 11-34. The antenna elements 11-33 are common to the A column antenna element group and the C row antenna element group.

Antenna elements 11-13, 11-23, 11-33, 11-43 are connected to transceiver modules 12-13, 12-23, 12-33, 12-43, respectively. The antenna elements 11-31, 11-32, 11-34 are respectively connected to transceiver modules 12-31, 12-32, 12-34.

The divider/combiner 13 includes a plurality of circulators 20 , a plurality of dividers 21 and a plurality of 4-combiners 22 . In the example of FIG. 4, the divider/combiner 13 includes circulators 20-13, 20-23, 20-33, 20-43, 20-31, 20-32, 20-34 and dividers 21-13, 21- 23, 21-33, 21-43, 21-31, 21-32, 21-34 and four combiners 22-1, 22-2.

The first terminals of the circulators 20-13, 20-23, 20-33, 20-43 are connected to the transceiver modules 12-13, 12-23, 12-33, 12-43, respectively. The first terminals of the circulators 20-31, 20-32, 20-34 are respectively connected to the transceiver modules 12-31, 12-32, 12-34.

The second terminals of the circulators 20-13, 20-23, 20-33, 20-43 are connected to the input terminals of the distributors 21-13, 21-23, 21-33, 21-43, respectively. The second terminals of the circulators 20-31, 20-32, 20-34 are connected to the input terminals of the distributors 21-31, 21-32, 21-34, respectively.

A transmission signal TX is input from the transmitter 15 shown in FIG. 1 to a third terminal of the circulator 20 . The circulator 20 is an element that allows the signal input to each terminal to pass through only in one direction (the arrow direction shown in the drawing). The circulator 20 switches paths between the received signal and the transmitted signal TX.

A splitter 21 splits the received signal into two signal components. That is, the distributor 21 consists of two distributors. The distributor 21-13 outputs the received signal EL1. The received signal EL1 is input to the 4-combiner 22-1. The distributors 21-23 output the received signal EL2. The received signal EL2 is input to the 4-combiner 22-1. The distributor 21-33 outputs the received signal EL3. The received signal EL3 is input to the 4-combiner 22-1 and 4-combiner 22-2. The distributor 21-43 outputs the received signal EL4. The received signal EL4 is input to the 4-combiner 22-1.

Distributor 21-31 outputs received signal AZ1. The received signal AZ1 is input to the 4-combiner 22-2. Distributor 21-32 outputs received signal AZ2. Received signal AZ2 is input to 4-combiner 22-2. Distributor 21-34 outputs received signal AZ4. The received signal AZ4 is input to the 4-combiner 22-2.

Each of the 4-combiners 22-1 and 22-2 combines the four received signals. The 4-combiner 22-1 synthesizes the received signals EL1, EL2, EL3, and EL4, and outputs a received signal AZ3 which is a 4-combined output. The 4-combiner 22-2 synthesizes the received signals AZ1, AZ2, EL3 and AZ4, and outputs a received signal EL3 which is a 4-combined output.

FIG. 5 is a block diagram of the divider/combiner 13 corresponding to the BC array antenna element group shown in FIG.

The B-row antenna element group shown in FIG. 5 consists of antenna elements 11-21 and 11-31. The row C antenna element group shown in FIG. 5 consists of antenna elements 11-31, 11-32, 11-33, and 11-34. The antenna elements 11-31 are common to the B-column antenna element group and the C-row antenna element group.

Antenna elements 11-21, 11-31 are connected to transceiver modules 12-21, 12-31, respectively. Antenna elements 11-32, 11-33, 11-34 are connected to transceiver modules 12-32, 12-33, 12-34, respectively.

In the example of FIG. 5, the divider/combiner 13 includes circulators 20-21, 20-31, 20-, 20-32, 20-33, and 20-34, distributors 21-21, 21-31, and 21-32. , 21-33, 21-34, a 4-combiner 22-2 and a 2-combiner 22-3.

First terminals of the circulators 20-21, 20-31 are connected to the transmitting/receiving modules 12-21, 12-31, respectively. The first terminals of the circulators 20-32, 20-33, 20-34 are respectively connected to the transceiver modules 12-32, 12-33, 12-34.

Second terminals of the circulators 20-21 and 20-31 are connected to input terminals of the distributors 21-21 and 21-31, respectively. The second terminals of the circulators 20-32, 20-33, 20-34 are connected to the input terminals of the distributors 21-32, 21-33, 21-34, respectively.

The distributor 21-21 outputs the received signal EL2. The received signal EL2 is input to the 2-combiner 22-3. The distributor 21-31 outputs the received signal EL3. The received signal EL3 is input to the 2-combiner 22-3 and the 4-combiner 22-2.

Distributor 21-32 outputs received signal AZ2. Received signal AZ2 is input to 4-combiner 22-2. Distributor 21-33 outputs received signal AZ3. The received signal AZ3 is input to the 4-combiner 22-2. Distributor 21-34 outputs received signal AZ4. The received signal AZ4 is input to the 4-combiner 22-2.

The 2-combiner 22-3 combines the two received signals. That is, the 2-combiner 22-3 combines the received signals EL2 and EL3 and outputs a received signal AZ1 which is a 2-combined output. The 4-combiner 22-2 combines the four received signals. That is, the 4-combiner 22-2 synthesizes the received signals EL3, AZ2, AZ3, and AZ4, and outputs the received signal EL3 which is a 4-combined output.

[3] Configuration of Transmission/Reception Module 12 Next, the configuration of the transmission/reception module 12 will be described. FIG. 6 is a block diagram of the transmitting/receiving module 12 shown in FIG.

The transmission/reception module 12 includes a harmonic suppression filter 30, a circulator 31, a limiter 32, an attenuator (attenuator) 40, low noise amplifiers 33 and 34, an SPDT (single-pole double-throw) switch 35, a phase shifter 36, and an excitation amplifier. 37 and a power amplifier 38 .

A received signal is output through a harmonic suppression filter 30, a circulator 31, a limiter 32, an attenuator 40, low noise amplifiers 33 and 34, an SPDT switch 35, and a phase shifter . A transmission signal is output via phase shifter 36 , SPDT switch 35 , excitation amplifier 37 , power amplifier 38 , circulator 31 and harmonic suppression filter 30 .

The harmonic suppression filter 30 is composed of a BEF (band elimination filter). The harmonic suppression filter 30 suppresses harmonics such as the second harmonic. The circulator 31 switches paths between the received signal and the transmitted signal. The limiter 32 has a function of limiting the signal level of the input signal to protect the circuit in the subsequent stage from excessive input.

The attenuator 40 attenuates the signal level (amplitude) of the input signal by a predetermined attenuation amount. A specific configuration of the attenuator 40 will be described later. In this embodiment, the attenuator 40 is inserted in the front stage (input section of the low noise amplifier 33) of the low noise amplifier 33 in the subsequent stage.

The low noise amplifiers 33 and 34 amplify the input signals with low noise. The SPDT switch 35 switches the path between the received signal and the transmitted signal. Phase shifter 36 controls the phase of the input signal.

The excitation amplifier 37 amplifies the input signal so that the input signal to the power amplifier 38 in the subsequent stage has an appropriate amplitude. Power amplifier 38 amplifies the power of the input signal.

FIG. 7 is a circuit diagram of attenuator 40 shown in FIG.

The attenuator 40 has an input terminal 41 , an output terminal 42 , a control terminal 43 , capacitors 44 to 46 , transmission lines 47 and 48 , a PIN diode 49 and a resistor 50 .

Input terminal 41 is connected to the output of limiter 32 shown in FIG. The output terminal 42 is connected to the input of the low noise amplifier 33 shown in FIG. The control terminal 43 is a terminal for controlling the shorted state and open state of the PIN diode 49 .

One end of the capacitor 44 is connected to the input terminal 41 . The other end of capacitor 44 is connected to one end of transmission line 47 , the anode of PIN diode 49 , and one end of capacitor 45 . The other end of capacitor 45 is connected to output terminal 42 .

The other end of the transmission line 47 is connected to the control terminal 43 and one end of the capacitor 46 . The other end of capacitor 46 is grounded (connected to ground terminal GND).

The cathode of PIN diode 49 is connected to one end of transmission line 48 and one end of resistor 50 . The other end of transmission line 48 and the other end of resistor 50 are grounded.

Capacitors 44 to 46 have the function of cutting DC components. The resistor 50 has a function of attenuating high frequency signals.

PIN diode 49 functions as a switch. The PIN diode 49 is a PIN junction diode that includes a P-type semiconductor layer, an N-type semiconductor layer, and a high resistivity layer (intrinsic layer, intrinsic semiconductor layer) interposed therebetween. Applying a forward bias to the PIN diode 49 results in a shorted state (on state). When a reverse bias is applied to the PIN diode 49, it becomes an open state (off state).

The transmission lines 47 and 48 are composed of quarter-wave lines. That is, the quarter-wavelength lines 47 and 48 are transmission lines having a length of 1/4 of the wavelength λ of the high-frequency signal handled by the antenna device 1 . The 1/4 wavelength lines 47 and 48 are composed of microstrip lines, for example. The quarter-wave lines 47 and 48 function as lines having high impedance, ideally infinite impedance, with respect to the input high-frequency signal.

The quarter-wave lines 47 and 48, the control terminal 43, and the capacitor 46 function as a bias circuit that applies a bias (forward bias and reverse bias) to the PIN diode 49. FIG. A bias voltage (a positive voltage and a negative voltage) is applied to the control terminal 43 from the control circuit 14 . A bias voltage applied to the control terminal 43 is applied to the anode of the PIN diode 49 via the quarter-wave line 47 . A quarter-wave line 48 applies 0V to the cathode of the PIN diode 49 .

This allows the bias circuit to apply a forward bias to the PIN diode 49 when a positive bias voltage is applied to the control terminal 43 . Also, when a negative bias voltage is applied to the control terminal 43 , the bias circuit can apply a reverse bias to the PIN diode 49 .

[4] Operation The operation of the antenna device 1 configured as described above will be described.

Antenna element 11 receives a high frequency signal. A high-frequency signal received by the antenna element 11 is input to the transmission/reception module 12 .

The antenna device 1 is capable of two modes of operation: maximum detection mode and proximity mode.

The maximum seek mode is the mode that maximizes the amplitude of the received signal. The maximum detection mode is used to detect objects that are farther from the antenna device 1 .

The proximity mode is a mode that makes the amplitude of the received signal uniform by making the amplitude smaller than that of the maximum detection mode. The proximity mode is used to improve the accuracy of angle measurement when the distance between the antenna device 1 and the object approaches.

First, the maximum detection mode will be explained.

In the maximum detection mode, the attenuators 40 included in all transmission/reception modules 12 are set to pass mode. The control circuit 14 applies a negative voltage to the control terminal 43 and applies a reverse bias to the PIN diode 49 . As a result, the inter-terminal impedance of the PIN diode 49 is set open. Therefore, since the high frequency signal is not input to the resistor 50 included in the attenuator 40, the attenuator 40 passes the input high frequency signal without attenuating it.

A high-frequency signal output from the transmission/reception module 12 is input to the divider/combiner 13 . As shown in FIG. 3, when the divider/combiner 13 scans in the AZ direction, the received signal AZ1 with two combined outputs, the received signal AZ2 with four combined outputs, the received signal AZ3 with four combined outputs, and the received signal with two combined outputs Output AZ4. Further, when scanning in the EL direction, the divider/combiner 13 outputs a received signal EL1 with 2-combined output, a received signal EL2 with 4-combined output, a received signal EL3 with 4-combined output, and a received signal EL4 with 2-combined output. That is, the signal levels of the received signals AZ2, AZ3, EL2 and EL3 can be increased.

Next, the proximity mode will be described.

In the proximity mode, the attenuators 40 included in the transmission/reception modules 12 connected to the central antenna element group are set to the attenuation mode, and the attenuators 40 included in the transmission/reception modules 12 connected to the peripheral antenna element groups are set to the pass mode. set to

In the example of FIGS. 2 and 3, when scanning in the AZ direction, the attenuators 40 corresponding to the second and third row antenna element groups corresponding to the central portion are set to the attenuation mode, and the attenuators 40 corresponding to the peripheral portion are set to the attenuation mode. The attenuators 40 corresponding to the groups of antenna elements in the 4th and 4th columns are set to the pass mode. When scanning in the EL direction, the attenuators 40 corresponding to the second row and third row antenna element groups corresponding to the central portion are set to the attenuation mode, and the first row and fourth row antenna elements corresponding to the peripheral portion are set to the attenuation mode. The attenuators 40 corresponding to the groups are set to pass-through mode.

In decay mode, control circuit 14 applies a positive voltage to control terminal 43 and forward biases PIN diode 49 . As a result, the inter-terminal impedance of the PIN diode 49 is set to a short circuit. Therefore, the high frequency signal is input to the resistor 50 included in the attenuator 40, and the attenuator 40 attenuates the input high frequency signal by the set attenuation amount. The high frequency signal attenuated by the attenuator 40 is input to the low noise amplifier 33 in the subsequent stage.

Pass-through mode operation at the perimeter is the same as for maximum detection mode.

Here, the attenuator 40 changes the amount of attenuation according to the gain difference between the combined gain of the central antenna element group and the combined gain of the peripheral antenna element group. Specifically, since the combined gain of the central antenna element group is twice the combined gain of the peripheral antenna element group, the gain difference is approximately 3 dB. Therefore, the attenuation of the attenuator 40 is set to approximately 3 dB. The resistance value that determines the attenuation of attenuator 40 is the total resistance value of the equivalent series resistance value of PIN diode 49 and the resistance value of resistor 50 .

Next, a specific example of the attenuation amount of the attenuator 40 will be described. FIG. 8 is a graph explaining the insertion loss when the attenuator 40 is open. FIG. 9 is a graph for explaining the insertion loss when the attenuator 40 is short-circuited. The horizontal axis of FIGS. 8 and 9 is the frequency [GHz], and the vertical axis is the loss [dB]. For example, assume that the inter-terminal capacitance of the PIN diode 49 is 0.1 pF, the equivalent series resistance value of the PIN diode 49 is 10Ω, and the resistance value of the resistor 50 is 40Ω.

As shown in FIGS. 8 and 9, the insertion loss at open is approximately 0.5 dB, and the insertion loss at short is approximately 3.5 dB. Therefore, the loss can be changed by approximately 3 dB between open and short circuits.

In this embodiment, a difference in combined gain of approximately 3 dB occurs between the peripheral portion and the central portion, but by inserting an attenuator that attenuates the central portion by 3 dB, the above difference is canceled and the signal level is reduced. The peripheral part and the central part are approximately the same.

Although the gain of the central transceiver module is reduced by 3 dB due to the 3 dB attenuator, the noise figure of the central transceiver module is increased by 3 dB. Output power will be equal. Therefore, no problem in signal processing occurs.

[5] Comparative Example Next, a comparative example will be described.

FIG. 10 is a schematic diagram explaining the layout of the array antenna 10 according to the comparative example. In the comparative example, the group of antenna elements in the central portion can generate received signals with 2 combined outputs and received signals with 4 combined outputs. A received signal of four combined outputs is used in the maximum detection mode. A received signal of two combined outputs is used in proximity mode.

FIG. 11 is a block diagram of the divider/combiner 13 corresponding to the AC train antenna element group according to the comparative example.

The distributor/combiner 13 includes a plurality of distributors 61 and a plurality of 2-combiners 62 . The distributor 61-13 distributes the received signal EL1. The distributor 61-23 distributes the received signal EL2. The distributor 61-33 distributes the received signal EL3. The distributor 61-43 distributes the received signal EL4. Distributor 61-31 distributes received signal AZ1. Distributor 61-32 distributes received signal AZ2. Distributor 61-34 distributes received signal AZ4. The distributor 61-5 distributes the received signal EL3.

The outputs of distributors 61-13, 61-23, 61-33 and 61-43 are input to 4-combiner 22-1. The 4-combiner 22-1 outputs a received signal AZ3 which is a 4-combined output.

The outputs of distributors 61-23 and 61-33 are input to 2-combiner 62-1. The 2-combiner 62-1 outputs a received signal AZ3 which is a 2-combined output.

The outputs of the distributors 61-31, 61-32, 61-34 and 61-5 are input to the 4-combiner 22-2. The 4-combiner 22-2 outputs a received signal EL3 which is a 4-combined output.

The outputs of the distributors 61-32 and 61-34 are input to the 2-combiner 62-2. The 2-combiner 62-2 outputs a received signal EL3 which is a 2-combined output.

FIG. 12 is a block diagram of the divider/combiner 13 corresponding to the BC-sequence antenna element group according to the comparative example.

The distributor 61-21 distributes the received signal EL2. The distributor 61-31 distributes the received signal EL3. The distributor 61-6 distributes the received signal EL3. Distributor 61-32 distributes received signal AZ2. Distributor 61-33 distributes received signal AZ3. Distributor 61-34 distributes received signal AZ4.

The outputs of the distributors 61-21 and 61-31 are input to the 2-combiner 22-3. The 2-combiner 22-3 outputs a received signal AZ1 which is a 2-combined output.

The outputs of distributors 61-6, 61-32, 61-33 and 61-34 are input to 4-combiner 22-2. The 4-combiner 22-2 outputs a received signal EL3 which is a 4-combined output.

The outputs of the distributors 61-32 and 61-33 are input to the 2-combiner 62-2. The 2-combiner 62-2 outputs a received signal EL3 which is a 2-combined output.

FIG. 13 is a block diagram of a transmission/reception module 12 according to a comparative example. The transceiver module 12 comprises a harmonic suppression filter 30, a circulator 31, a limiter 32, low noise amplifiers 33, 34, an SPDT switch 35, a phase shifter 36, an excitation amplifier 37, and a power amplifier . The transmitting/receiving module 12 according to the comparative example does not include the attenuator 40 described in the embodiment. That is, the output of limiter 32 is connected to the input of low noise amplifier 33 .

In the comparative example, an additional divider is required to distribute to the 2 combiners and the 4 combiners in the central portion. Also, two more synthesizers for the central part are required. Also, in the comparative example, in the case of the number of antenna elements in FIG. In the central part, there are 4 lines for 2 combined outputs and 4 combined outputs for 4 combined outputs, for a total of 12 lines. In addition, it is necessary to switch between 2-combined output and 4-combined output in the central part by means of a frequency converter or the like, which is disadvantageous in miniaturization of equipment.

On the other hand, in this embodiment, since only four combiners are required in the central portion, the number of distributors can be greatly reduced compared to the comparative example, and two combiners for the central portion can also be reduced. In addition, in this embodiment, as shown in FIG. 3, the number of RF cables is four in each of the AZ direction and the EL direction, for a total of eight, which can be reduced by four compared to the comparative example.

[6] Effect of Embodiment As described in detail above, in the present embodiment, the array antenna 10 is such that the number of antenna elements in the central antenna element group is equal to the number of antenna elements in the peripheral antenna element group in the AZ direction, for example. configured to be more A plurality of transmit/receive modules connected to the central group of antenna elements includes an amplifier 33 for received signals and an attenuator 40 connected to the input of amplifier 33 . The attenuator 40 changes the amount of attenuation according to the gain difference between the combined gain of the central antenna element group and the combined gain of the peripheral antenna element group. Specifically, in the first mode (proximity mode), the attenuator 40 attenuates the received signal by an attenuation amount approximately equal to the gain difference. In the second mode (maximum detection mode), the attenuator 40 passes the received signal unattenuated. Therefore, according to this embodiment, the same combiner can be used for maximum detection mode and proximity mode. Therefore, the number of combiners can be reduced. Also, the number of distributors that supply received signals to the combiner can be reduced. Also, it is possible to reduce the number of RF cables required for connecting devices such as the divider/combiner and the frequency converter.

Thereby, the manufacturing cost of the antenna device 1 can be reduced, and the size of the antenna device 1 can be reduced. Moreover, as a result of being able to reduce the number of dividers and combiners, the performance of the antenna device 1 can be improved.

In addition, switching between the two types of combined output is not required in the central portion, so that a device for switching is not required. Thereby, the manufacturing cost of the antenna device 1 can be reduced, and the size of the antenna device 1 can be reduced.

While several embodiments of the invention have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and equivalents thereof.

DESCRIPTION OF SYMBOLS 1... Antenna apparatus, 10... Array antenna, 11... Antenna element, 12... Transmission/reception module, 13... Divider/synthesizer, 14... Control circuit, 15... Transmitter, 16... Receiver, 20... Circulator, 21... Distributor, 22... Synthesizer 30... Harmonic suppression filter 31... Circulator 32... Limiter 33... Low noise amplifier 34... Low noise amplifier 35... SPDT switch 36... Phase shifter 37... Excitation amplifier 38... Power amplifier 40 Attenuator 41 Input terminal 42 Output terminal 43 Control terminal 44 to 46 Capacitor 47, 48 Transmission line 49 PIN diode 50 Resistor 61 Distributor 62... Synthesizer.

Claims (8)

a plurality of antenna element groups arranged along a first direction, the plurality of antenna element groups comprising a first antenna element group arranged in the central portion and a second antenna element group arranged in the peripheral portion; each of the plurality of antenna element groups includes a plurality of antenna elements arranged in a second direction intersecting the first direction, and the number of antenna elements in the first antenna element group is equal to the second antenna element group an array antenna having a larger number of antenna elements than the number of antenna elements of
a plurality of first transmission/reception modules each connected to a plurality of antenna elements included in the first antenna element group and amplifying a transmission signal and a reception signal;
a plurality of second transmission/reception modules each connected to a plurality of antenna elements included in the second antenna element group and amplifying a transmission signal and a reception signal;
a first combiner for combining a plurality of first reception signals output from the plurality of first transmission/reception modules to generate a first combined signal;
a second combiner that combines the plurality of second received signals output from the plurality of second transceiver modules to generate a second combined signal;
and
each of the plurality of first transmission/reception modules includes a received signal amplifier and an attenuator connected to an input section of the amplifier;
The attenuator changes an attenuation amount in accordance with a gain difference between a combined gain of the first combined signal and a combined gain of the second combined signal. The antenna device according to claim 1, wherein the attenuation amount is approximately equal to the gain difference. 3. The antenna device according to claim 1, wherein the attenuator attenuates a received signal in the first mode and passes the received signal without attenuating in the second mode. The attenuator includes a PIN diode and a resistor, the anode of the PIN diode is connected to the input of the amplifier, the cathode of the PIN diode is connected to one end of the resistor, and the other end of the resistor. is grounded. 5. The antenna device according to claim 4, wherein the resistance value that determines the amount of attenuation is the total resistance value of the equivalent series resistance value of the PIN diode and the resistance value of the resistor. 6. The antenna device according to claim 4, wherein the attenuator includes a bias circuit that applies a forward bias or a reverse bias to the PIN diode. 7. The bias circuit of claim 6, wherein the bias circuit forward biases the PIN diode in a first mode that attenuates a received signal and reverse biases the PIN diode in a second mode that does not attenuate a received signal. An antenna device as described. a plurality of first distributors for respectively distributing the plurality of first received signals;
a plurality of second distributors for distributing the plurality of second received signals;
further comprising
The outputs of the plurality of first distributors are input to the first combiner,
The antenna device according to any one of claims 1 to 7, wherein outputs of the plurality of second distributors are input to the second combiner.