JP7463206B2 - Electronically scanned antenna and signal processing method thereof - Google Patents

Description

This embodiment of the invention relates to an electronically scanned antenna and its signal processing method.

In conventional electronically scanned antennas, multiple antenna elements are arranged in a planar array, and multiple transmit/receive modules that process transmission and reception by combining the multiple antennas are installed side by side. A distributor/synthesizer distributes and distributes the transmission signal to each transmit/receive module, and outputs a composite signal from each transmit/receive module. However, since both the transmit beam and receive beam are set to one direction, and the transmit and receive frequencies are the same for all antenna elements, there is a problem in that it is not possible to track multiple targets simultaneously.

JP 2019-161489 A JP 2008-153984 A JP 2004-505479 A

As described above, with conventional electronically scanned antenna configurations, both the transmit and receive beams are set in one direction, and the transmit and receive frequencies are the same for all antenna elements, which means that multiple targets cannot be tracked simultaneously.

The objective of the present invention is to provide a multi-beam electronically scanned antenna and its signal processing method that maintains the functionality and performance of a conventional single-beam electronically scanned antenna while allowing the frequency to be changed for each beam and enabling multiple targets to be tracked simultaneously.

According to the embodiment, the electronically scanned antenna includes an i-th (i is a natural number of 2 or more) four-element integrated transmission/reception module that performs transmission/reception processing for each of the first to fourth antenna elements and outputs first to fourth reception signals, and a distributor/synthesizer comparator that supplies a transmission signal to each of the i-th transmission/reception modules and divides, combines, and compares the i×4 reception signals output from each of the i-th transmission/reception modules to form multiple composite beams. The i-th transmission/reception module is provided at the reception system output end of each of the first to fourth antenna elements and includes a mode changeover switch that switches between a first mode in which the first and second reception signals are output and a second mode in which the third and fourth reception signals are output. The distributor/synthesizer comparator includes a processing system for the first mode and a processing system for the second mode. The processing system of the first mode includes a combiner and a first comparison and synthesis means using a 90° hybrid connected to the first and second terminals that input the first and second received signals so that a composite beam of all antenna elements is formed, and the processing system of the second mode includes a second comparison and synthesis means using a 90° hybrid connected to the third and fourth terminals that input the third and fourth received signals so that multiple beams are formed by dividing all antenna elements. This makes it possible to change the frequency for each beam while maintaining the functions and performance of a conventional one-beam electronically scanned antenna.

FIG. 1 is a block diagram showing a configuration of an electronically scanned antenna according to an embodiment when a first mode is selected. FIG. 2 is a block diagram showing a configuration of the electronically scanned antenna according to the embodiment when the second mode is selected. FIG. 3 is a plan view showing an array of antenna elements of an electronically scanned antenna to which the embodiment is applied. FIG. 4 is a block diagram showing an internal system of a transmitting/receiving module of an electronically scanned antenna to which the embodiment is applied. FIG. 5 is a block diagram showing an internal system of an RF switch-integrated 3-bit MMIC phase shifter of an electronically scanned antenna to which the embodiment is applied.

Hereinafter, an embodiment will be described with reference to the drawings.
FIGS. 1 and 2 respectively show the configuration of the electronically scanned antenna according to the embodiment when the first mode is selected and the configuration when the second mode is selected, and FIGS. 3 to 5 respectively show the antenna element arrangement of the electronically scanned antenna to which this embodiment is applied, the internal system of a transmission/reception module, and the internal system of a 3-bit MMIC phase shifter integrated with an RF switch.

In Fig. 1, the antenna element 1 is shared by transmission and reception (RF_IN/OUT), and is arranged in 8 rows and 8 columns in the EL and AZ directions as shown in Fig. 3. It is divided into units of 4 elements arranged in one column in the same direction, and each is connected to the 1st to 16th transmission and reception modules 2 (No. 1 to No. 16) that are integrated with 4 elements. The transmission and reception modules 2 are capable of independent phase control using an internal phase shifter, and can form transmission beams and reception beams in any direction by phase control, transmit radio waves in the direction in which the transmission beam is formed, and receive radio waves arriving from the direction in which the reception beam is formed.

As shown in FIG. 3, the first transceiver module 2 (No. 1) has first to fourth module units 2-1 to 2-4 corresponding to the first to fourth antenna elements 1. The first to fourth module units 2-1 to 2-4 have the same configuration.

The configuration of the first module unit 2-1 will be explained. This first module unit 2-1 includes a mode switch (SPDT) 2-121, a phase shifter (PS) 2-11 that controls the phase of the transmission and reception signals, a TX/RX switch (SPDT) 2-122, an intermediate amplifier (MPA) 2-13 that intermediately amplifies the transmission signal, a driver (DRV) 2-14 for pulse driving, an attenuator (ATT) 2-15 for adjusting the output gain, a high-power amplifier (HPA) 2-16 that power amplifies the transmission signal, a circulator (CIR) 2-17, a band-limiting filter (BEF) 2-18 that removes unwanted waves, a limiter (LIM) 2-19 that limits the gain of the reception signal, a low-noise amplifier (LNA) 2-1A that amplifies the reception signal with low noise, LNA switches (SPDT) 2-1B1, 2-1B2 that control the on/off of the LNA 2-1A before and after it, and an intermediate amplifier (MPA) 2-1C that intermediately amplifies the reception signal.

A mode changeover switch (SPDT) 2-121 is disposed at the transmission/reception input/output end of each of the first and second module units 2-1 and 2-2. When each mode changeover switch 2-121 selects the first mode (side 1 in the figure), it is connected to the first and second terminals of the first 2-combiner (2-way splitter in the transmission system) 2-51. The third terminal of this first 2-combiner 2-51 is connected to the transmission/reception end (T/R-A) of the A system. When each mode changeover switch 2-121 selects the second mode (side 2 in the figure), it is connected to the first and second terminals of the second 2-combiner (2-way splitter in the transmission system) 2-52. The third terminal of this second 2-combiner 2-52 is connected to the EL output end (EL).

In addition, a mode changeover switch (SPDT) 2-121 is disposed at the transmission/reception input/output end of the third and fourth module units 2-3 and 2-4, and when each mode changeover switch 2-121 selects the first mode (side 1 in the figure), it is connected to the first and second terminals of the third 2 combiner (2-way splitter in the transmission system) 2-53. The third terminal of this third 2 combiner 2-53 is connected to the transmission/reception end (T/R-B) of the B system. In addition, when each mode changeover switch 2-121 selects the second mode (side 2 in the figure), it is connected to the first and second terminals of the fourth 2 combiner (2-way splitter in the transmission system) 2-54. The third terminal of this fourth 2 combiner 2-54 is connected to the Σ output end (Σ).

The second through sixteenth transceiver modules 2 (No. 2 to No. 16) have the same configuration as the first transceiver module 2 (No. 1).

In the first to sixteenth transmission/reception modules 2 (No. 1 to No. 16), when the mode changeover switch 2-121 selects the first mode, it is configured as shown in FIG. 1, and when the mode changeover switch 2-121 selects the second mode, it is configured as shown in FIG. 2.

First, in the case of mode 1 shown in FIG. 1, the transmitting and receiving ends of each of the two systems (T/R-A, T/R-B) are connected to the first and second terminals of the first to sixteenth 2-combiners (2-combiners in the transmitting system) 3-11 to 3-116 of the distribution/combination comparator 3.

The third terminals of the first and ninth 2-combiners 3-11, 3-19 are connected to the first and second terminals of the first EL comparison combiner 3-21 using a 90° hybrid (HYB).

The third terminals of the second and tenth 2-combiners 3-12, 3-110 are connected to the first and second terminals of the second EL comparison combiner 3-22 using a 90° hybrid.

The third terminals of the third and eleventh 2-combiners 3-13, 3-111 are connected to the first and second terminals of the third EL comparison combiner 3-23 using a 90° hybrid.

The third terminals of the fourth and twelfth 2-combiners 3-14, 3-112 are connected to the first and second terminals of the fourth EL comparison combiner 3-24 using a 90° hybrid.

The third terminals of the fifth and thirteenth 2-combiners 3-15, 3-113 are connected to the first and second terminals of the fifth EL comparison combiner 3-25 using a 90° hybrid.

The third terminals of the sixth and fourteenth 2-combiners 3-16, 3-114 are connected to the first and second terminals of the sixth EL comparison combiner 3-26 using a 90° hybrid.

The third terminals of the seventh and fifteenth 2 combiners 3-17, 3-115 are connected to the first and second terminals of the seventh EL comparison combiner 3-27 using a 90° hybrid.

The third terminals of the eighth and sixteenth 2 combiners 3-18, 3-116 are connected to the first and second terminals of the eighth EL comparison combiner 3-28 using a 90° hybrid.

The third terminals of the first to eighth EL comparators and combiners 3-21 to 3-28 are output terminals of EL1 to EL8, and are connected to the first to eighth terminals of the 8-combiner 3-3, respectively. The ninth terminal of the 8-combiner 3-3 is connected to the EL output terminal.

The fourth terminals of the first to fourth EL comparators 3-21 to 3-24 are output terminals of Σ1 to Σ4, and are connected to the first to fourth terminals of the first 4-combiner 3-51 via circulators 3-41 to 3-44, respectively. The fourth terminals of the fifth to eighth EL comparators 3-25 to 3-28 are output terminals of Σ5 to Σ8, and are connected to the first to fourth terminals of the second 4-combiner 3-52 via circulators 3-45 to 3-48, respectively.

The fifth terminals of the first and second 4-combiners 3-51 and 3-52 are connected to the first and second terminals of the AZ comparison combiner 3-6, which is a 90° hybrid (HYB). The third terminal of the AZ comparison combiner 3-6 is connected to the Σ output terminal, and the fourth terminal is connected to the AZ output terminal.

The first to eighth circulators 3-41 to 3-48 are each supplied with a signal that is obtained by splitting the transmission signal input from the TX input terminal into eight by the eight-way splitter 3-7.

On the other hand, in the case of mode 2 shown in Fig. 2, the EL signal output terminals EL1 to EL4 and Σ output terminals Σ1 to Σ4 of the transmitting/receiving modules 2 (No. 1 to No. 4) of the antenna ANT#1 are respectively connected to the first terminals (EL input terminals) and second terminals (Σ input terminals) of the EL comparison combiners 3-29 to 3-212 of the corresponding 90° hybrids (HYB) of the distribution/combining comparator 3. The third terminals (EL output terminals) of the EL comparison combiners 3-29 to 3-212 are respectively connected to the first to fourth terminals (EL1 to EL4 input terminals) of the first 4 combiner 3-31. The fifth terminal (EL1 to EL4 combined output terminal) of the first 4 combiner 3-31 is connected to the ANT#1_EL output terminal. The fourth terminals (Σ output terminals) of the EL comparators and combiners 3-29 to 3-212 are connected to the first terminal (Σ1 input terminal) of the 2 combiner 3-81, the second terminal (Σ2 input terminal) of the 2 combiner 3-81, the first terminal (Σ3 input terminal) of the 2 combiner 3-82, and the second terminal (Σ4 input terminal) of the 2 combiner 3-82 via the circulators 3-49 to 3-412, respectively. The third terminal (combination output terminal) of the 2 combiner 3-81 and the third terminal (combination output terminal) of the 2 combiner 3-82 are connected to the first terminal and the second terminal of the comparator and combiner 3-62 by a 90° hybrid (HYB), respectively. The third terminal of the comparator and combiner 3-62 is connected to the ANT#1_Σ output terminal. Also, the fourth terminal of the comparator and combiner 3-62 is connected to the ANT#1_AZ output terminal. Meanwhile, the transmission signal for the first antenna supplied from the TX#1 input terminal is split into four by a 4-way splitter 3-71 to become TX1 to TX4, which are then sent from the comparators 3-29 to 3-212 via circulators 3-49 to 3-412 to each of the transmission/reception modules 2 (No. 1 to No. 4).

Similarly, the EL signal output terminals EL5 to EL8 and Σ output terminals Σ5 to Σ8 of the transmitting/receiving modules 2 (No. 5 to No. 8) of the antenna ANT#2 are respectively connected to the first terminals (EL input terminals) and second terminals (Σ input terminals) of the EL comparison combiners 3-213 to 3-216 formed by the corresponding 90° hybrids (HYB) of the distribution/combining comparator 3. The third terminals (EL output terminals) of the EL comparison combiners 3-213 to 3-216 are respectively connected to the first to fourth terminals (EL5 to EL8 input terminals) of the second 4-combiner 3-32. The fifth terminal (EL5 to EL8 combined output terminal) of the second 4-combiner 3-32 is connected to the ANT#2_EL output terminal. The fourth terminals (Σ output terminals) of the EL comparators and combiners 3-213 to 3-216 are connected to the first terminal (Σ5 input terminal) of the 2 combiner 3-83, the second terminal (Σ6 input terminal) of the 2 combiner 3-83, the first terminal (Σ7 input terminal) of the 2 combiner 3-84, and the second terminal (Σ8 input terminal) of the 2 combiner 3-84 via the circulators 3-413 to 3-416, respectively. The third terminal (combination output terminal) of the 2 combiner 3-83 and the third terminal (combination output terminal) of the 2 combiner 3-84 are connected to the first terminal and the second terminal of the comparator and combiner 3-63 by a 90° hybrid (HYB), respectively. The third terminal of the comparator and combiner 3-63 is connected to the ANT#2_Σ output terminal. Also, the fourth terminal of the comparator and combiner 3-63 is connected to the ANT#2_AZ output terminal. Meanwhile, the transmission signal for the second antenna supplied from the TX#2 input terminal is split into four by a 4-way splitter 3-72 to become TX5 to TX8, which are then sent from the comparators 3-213 to 3-216 via circulators 3-413 to 3-416 to each of the transmission/reception modules 2 (No. 5 to No. 8).

Similarly, the EL signal output terminals EL9 to EL12 and Σ output terminals Σ9 to Σ12 of the transmitting/receiving modules 2 (No. 9 to No. 12) of the antenna ANT#3 are respectively connected to the first terminals (EL input terminals) and second terminals (Σ input terminals) of the EL comparison combiners 3-217 to 3-220 of the corresponding 90° hybrids (HYB) of the distribution/combining comparator 3. The third terminals (EL output terminals) of the EL comparison combiners 3-217 to 3-220 are respectively connected to the first to fourth terminals (EL9 to EL12 input terminals) of the third 4 combiner 3-33. The fifth terminal (EL9 to EL12 combined output terminal) of the third 4 combiner 3-33 is connected to the ANT#3_EL output terminal. The fourth terminals (Σ output terminals) of the EL comparators and combiners 3-217 to 3-220 are connected to the first terminal (Σ9 input terminal) of the 2 combiner 3-85, the second terminal (Σ10 input terminal) of the 2 combiner 3-85, the first terminal (Σ11 input terminal) of the 2 combiner 3-86, and the second terminal (Σ12 input terminal) of the 2 combiner 3-86 via the circulators 3-417 to 3-420, respectively. The third terminal (combination output terminal) of the 2 combiner 3-85 and the third terminal (combination output terminal) of the 2 combiner 3-86 are connected to the first terminal and the second terminal of the comparator and combiner 3-64 by a 90° hybrid (HYB), respectively. The third terminal of the comparator and combiner 3-64 is connected to the ANT#3_Σ output terminal. Also, the fourth terminal of the comparator and combiner 3-64 is connected to the ANT#3_AZ output terminal. Meanwhile, the transmission signal for the third antenna supplied from the TX#3 input terminal is split into four by a four-way splitter 3-73 to become TX9 to TX12, which are then sent to each of the transmission/reception modules 2 (No. 9 to No. 12) from comparators 3-217 to 3-220 via circulators 3-417 to 3-420.

Similarly, the EL signal output terminals EL13 to EL16 and Σ output terminals Σ13 to Σ16 of the transmitting/receiving modules 2 (No. 13 to No. 16) of the antenna ANT#4 are respectively connected to the first terminals (EL input terminals) and second terminals (Σ input terminals) of the EL comparison combiners 3-221 to 3-224 of the corresponding 90° hybrids (HYB) of the distribution/combining comparator 3. The third terminals (EL output terminals) of the EL comparison combiners 3-221 to 3-224 are respectively connected to the first to fourth terminals (EL13 to EL16 input terminals) of the fourth 4-combiner 3-34. The fifth terminal (EL13 to EL16 combination output terminal) of the fourth 4-combiner 3-34 is connected to the ANT#4_EL output terminal. The fourth terminals (Σ output terminals) of the EL comparators and combiners 3-221 to 3-224 are connected to the first terminal (Σ13 input terminal) of the 2 combiner 3-87, the second terminal (Σ14 input terminal) of the 2 combiner 3-87, the first terminal (Σ15 input terminal) of the 2 combiner 3-88, and the second terminal (Σ16 input terminal) of the 2 combiner 3-88 via the circulators 3-421 to 3-424, respectively. The third terminal (combination output terminal) of the 2 combiner 3-87 and the third terminal (combination output terminal) of the 2 combiner 3-88 are connected to the first terminal and the second terminal of the comparator and combiner 3-65 by a 90° hybrid (HYB), respectively. The third terminal of the comparator and combiner 3-65 is connected to the ANT#4_Σ output terminal. Also, the fourth terminal of the comparator and combiner 3-65 is connected to the ANT#4_AZ output terminal. Meanwhile, the transmission signal for the third antenna supplied from the TX#4 input terminal is split into four by a four-way splitter 3-74 to become TX13 to TX16, which are then sent from the comparators 3-221 to 3-224 via circulators 3-421 to 3-424 to each of the transmission/reception modules 2 (No. 13 to No. 16).

The mode changeover switch (SPDT) 2-121, phase shifter (PS) 2-11, and TX/RX changeover switch (SPDT) 2-122 of the module unit 2-1 (2-2 to 2-4 are also the same) are integrated as shown within the dashed line in Figure 3, and are realized as a 3-bit digital phase shifter 2-1D with an integrated RF switch using an MMIC (monolithic microwave integrated circuit).

Figure 4 is a block diagram showing the internal system of the RF switch integrated 3-bit MMIC phase shifter 2-1D. This phase shifter 2-1D has a typical 3-bit configuration, and the phase is switched in 45-degree steps by switching the SPDT RF switches SW11, SW12, SW21, SW12, SW31, and SW12 arranged in front and behind the line with a phase difference of 45 degrees (L1), the line with a phase difference of 90 degrees (L2), and the line with a phase difference of 180 degrees (L3). Furthermore, the MMIC phase shifter 2-1D has a mode switch (SPDT) 2-121 and a TX/RX switch (SPDT) 2-122 built in. In this case, since the MMIC already has many RF switches built in for line switching, the manufacturing cost of the MMIC hardly increases.

In the electronically scanned antenna with the above configuration, in mode 1, when a transmission signal TX is input, it is distributed by the 8-way distributor 3-7 into 8 transmission signals TX1 to TX8, which are input to the fourth terminals of the first to eighth EL comparison combiners 3-21 to 3-28 via the first to eighth circulators 3-41 to 3-48, respectively, and distributed from their first terminals to the third terminals of the first to eighth 2-combiners 3-11 to 3-18 of the first group, and distributed from their second terminals to the ninth to sixteenth 2-combiners 3-19 to 3-116 of the second group.

The transmission signals input to the first through eighth combiners 3-11 through 3-18 in the first group are distributed to systems A and B, and are supplied to systems A and B of the first through eighth transceiver modules 2 (No. 1 through No. 8), respectively.

The transmission signals input to the ninth through sixteenth combiners 3-19 through 3-116 of the second group are distributed to systems A and B, and are supplied to systems A and B of the ninth through sixteenth transceiver modules 2 (No. 9 through No. 16), respectively.

In each transmission/reception module 2, the transmission signal input from the transmission/reception input/output terminal of the A system is distributed to two systems by the 2-way combiner 2-51. One transmission signal is input to the first module unit 2-1, and when mode 1 is selected by the changeover switches (SPDT) 2-121 and 2-122 and transmission is selected, the phase is controlled by the phase shifter (PS) 2-11, intermediately amplified by the transmission system intermediate amplifier (MPA) 2-13, pulse-driven by the driver (DRV) 2-14, gain adjusted by the attenuator (ATT) 2-15, power amplified by the high-power amplifier (HPA) 2-16, passed through the circulator (CIR) 2-17, band-limited by the band-limiting filter (BEF) 2-18, and transmitted from the antenna element 1. The other transmission signal is input to the second module unit 2-2 and processed in the same manner as the first module unit 2-1.

In the first module unit 2-1, the reception signal of the antenna element 1 is band-limited by the band-limiting filter (BEF) 2-18, passes through the circulator (CIR) 2-17, is gain-limited by the limiter (LIM) 2-19, is amplified with low noise by the low-noise amplifier (LNA) 2-1A, the LNA is turned off as necessary by the LNA switches (SPDT) 2-1B1 and 2-1B2, is intermediately amplified by the reception system intermediate amplifier (MPA) 2-1C, is phase-controlled by the phase shifter (PS) 2-11 when the TX/RX changeover switch (SPDT) 2-122 selects reception, and is supplied to the first terminal of the second 2-combiner 2-51 in mode 1. The second module unit 2-2 is also processed in the same way as the first module unit 2-1, and its reception output is supplied to the second terminal of the first 2-combiner 2-51, is combined with the reception signal from the first module unit 2-1, and is output as the A system reception signal.

The transmission signal input from the transmission/reception input/output terminal of the B system is split into two systems by the third 2-combiner 2-53. One transmission signal is input to the third module unit 2-3, and the other transmission signal is input to the fourth module unit 2-4. Thereafter, the third and fourth module units 2-3, 2-4 are processed in the same way as the first and second module units 2-1, 2-2, and the respective reception signals are combined by the third 2-combiner 2-53 and output as the B system reception signal.

The A-system reception signals and B-system reception signals obtained by the first to sixteenth transmission/reception modules 2 are respectively supplied to the distribution/combination comparator 3 and combined in the first to sixteenth 2 combiners 3-11 to 3-116. Of these, the reception signals combined in the first to eighth 2 combiners 3-11 to 3-18 and the reception signals combined in the ninth to sixteenth 2 combiners 3-11 to 3-18 are respectively supplied to the first and second terminals of the first to eighth EL comparison combiners 3-21 to 3-28.

The composite signals (EL1 to EL8) output from the third terminals of the first to eighth EL comparators and combiners 3-21 to 3-28 are combined in the 8-combiner 3-4 and output from the EL output terminal.

The composite signals (Σ1 to Σ4) output from the fourth terminals of the first to fourth EL comparators 3-21 to 3-24 are supplied to the first to fourth terminals of the first 4-combiner 3-51 via the first to fourth circulators 3-41 to 3-44, respectively, and the composite signals (Σ5 to Σ8) output from the fourth terminals of the fifth to eighth EL comparators 3-25 to 3-28 are supplied to the first to fourth terminals of the second 4-combiner 3-52 via the fifth to eighth circulators 3-45 to 3-48, respectively. The received signals combined by the first and second 4-combiners 3-51 and 3-52 are supplied to the first and second terminals of the AZ comparator combiner 3-61, respectively, and the Σ signal is output from the third terminal of the AZ comparator combiner 3-61, and the AZ composite signal is output from the fourth terminal.

When the mode changeover switch (RF switch for switching reception output) 2-121 provided on each module unit 2-1 to 2-4 of the transmission/reception module 2 is set to side 1, the reception signals are combined as shown in FIG. 1 by comparing the combined signals of the upper eight transmission/reception modules (No. 1 to No. 8) and the lower eight transmission/reception modules (No. 9 to No. 16) in the EL comparison and combination devices 3-21 to 3-28 to obtain an EL signal, and the combined signals of the right eight transmission/reception modules (No. 1 to No. 4 and No. 9 to No. 12) and the left eight transmission/reception modules (No. 5 to No. 8 and No. 13 to No. 16) in the AZ comparator 3-61 to obtain an AZ signal, and the antenna functions as a one-beam electronically scanned antenna.

In addition, when the mode changeover switch (RF switch for switching receiving output) 2-121 provided in each module unit 2-1 to 2-4 of the transmit/receive module 2 is set to side 2, as shown in Figure 2, an EL signal is obtained by comparing the composite signals of the upper side (first element and second element) of the transmit/receive module (No. 1 to No. 4) and the lower side (third element and fourth element) of the transmit/receive module (No. 1 to No. 4) in the EL comparison and combiner 3-29 to 3-224, and an AZ signal is obtained by comparing the composite signals of the transmit/receive module (No. 1 and No. 2, first element to fourth element) on the right side and the transmit/receive module (No. 3 and No. 4, first element to fourth element) on the left side in the AZ comparison and combiner 3-62, and it functions as a single electronically scanned antenna. Furthermore, the combination of the transceiver modules (No. 5 to No. 8), the combination of the transceiver modules (No. 9 to No. 12), and the combination of the transceiver modules (No. 13 to No. 16) each function as an independent electronically scanned antenna. In addition, there are four transmission inputs, and the transmission frequencies can be set independently, so there are no problems with radio interference.

In addition, since the operation switching between the single beam type and the independent multi-beam type can be achieved by the mode changeover switch (RF switch for changing the receiving output) of the transmission/reception module 2, no RF switching function is required inside the distribution/combining comparator 3.

As described above, in the electronically scanned antenna according to this embodiment, a mode changeover switch using an RF switch is provided in the receiving system output section of the transmitting/receiving module, and independent one-beam and multi-beam type synthesis comparators are provided within the distribution synthesis comparator. This makes it possible to change the frequency for each beam while maintaining the functionality and performance of a conventional one-beam electronically scanned antenna, making it possible to track multiple targets simultaneously.

The present invention is not limited to the above-described embodiment as it is, and in the implementation stage, the components can be modified and embodied without departing from the gist of the invention. In addition, various inventions can be formed by appropriately combining the multiple components disclosed in the above-described embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, components from different embodiments may be appropriately combined.

1...antenna element,
2: Transmitting and receiving modules (No. 1 to No. 16), 2-1 to 2-4: module units,
2-11: Phase shifter (PS), 2-121: Mode changeover switch (SPDT), 2-122: TX/RX changeover switch (SPDT), 2-13: Intermediate amplifier (MPA), 2-14: Driver (DRV), 2-15: Attenuator (ATT), 2-16: High-power amplifier (HPA), 2-17: Circulator (CIR), 2-18: Bandwidth limiting filter (BEF), 2-19: Limiter (LIM), 2-1A: Low-noise amplifier (LNA), 2-1B1, 2-1B2: LNA switch (SPDT), 2-1C: Intermediate amplifier (MPA), 2-51, 2-52: 2 combiner,
2-1D...RF switch integrated 3-bit MMIC phase shifter, L1...line with 45 degree phase difference, L2...line with 90 degree phase difference, L3...line with 180 degree phase difference, SW11, SW12, SW21, SW12, SW31, SW12...RF switches,
3...Dividing and combining comparator, 3-11 to 3-116...2 combiners (2-way distributor), 3-21 to 3-224...EL comparing and combining device, 3-3...8 combiners, 3-41 to 3-424...circulator, 3-51, 3-52...4 combiners, 3-61 to 3-65...AZ comparing and combining device, 3-7...8 dividers, 3-71 to 3-74...4 dividers, 3-81 to 3-88...2 combiners.

Claims (5)

an i-th (i is a natural number equal to or greater than 2) four-element integrated transceiver module that performs transmission and reception processing for each of the first to fourth antenna elements and outputs first to fourth reception signals;
a divider/combiner comparator that supplies a transmission signal to each of the i-th transmission/reception modules, and divides, combines, and compares the i-th × 4 reception signals output from each of the i-th transmission/reception modules to form a plurality of composite beams;
the i-th transmission/reception module includes a mode changeover switch provided at a reception system output terminal of each of the first to fourth antenna elements, the mode changeover switch changing over between a first mode for outputting the first and second reception signals and a second mode for outputting the third and fourth reception signals;
The divide-and-combine comparator includes:
a processing system for the first mode and a processing system for the second mode,
the processing system for the first mode includes a first comparison and synthesis means using a synthesizer and a 90° hybrid connected to first and second terminals for inputting the first and second received signals so that a synthetic beam of all antenna elements is formed;
The processing system for the second mode is an electronically scanned antenna having a second comparison and synthesis means using a 90° hybrid connected to third and fourth terminals for inputting the third and fourth received signals so that a plurality of beams are formed by dividing all antenna elements. The processing system of the first mode includes:
an i-th combiner for combining the first and second received signals of the i-th transceiver module;
an EL comparator group for performing EL comparison of pairs of outputs in an EL (elevation) direction of the i-th two combiners;
an electroluminescence combiner for combining first outputs of each of the electroluminescence comparators;
first and second AZ combiners for combining the second outputs of the EL comparators into two AZ (azimuth) systems;
2. The electronically scanned antenna according to claim 1, further comprising an AZ comparator for performing an AZ comparison of outputs from said first and second AZ combiners. The processing system of the second mode includes:
an i-th EL comparator using a 90° hybrid for performing an EL comparison of the first and second reception signals in the second mode of the i-th transceiver module;
an EL combiner that combines the first outputs of the i-th EL comparators in groups;
an AZ combiner that combines the second outputs of the i-th EL comparators into two AZ (azimuth) systems in units of the group;
2. The electronically scanned antenna according to claim 1, further comprising an AZ comparator using a 90° hybrid for performing AZ comparison of the output of said AZ combiner. The electronically scanned antenna of claim 1, wherein the mode changeover switch is built into an MMIC (monolithic microwave integrated circuit) that integrates a transmission/reception changeover switch and a digital phase shifter. an i-th (i is a natural number equal to or greater than 2) four-element integrated transceiver module that performs transmission and reception processing for each of the first to fourth antenna elements and outputs first to fourth reception signals;
a divider/combiner comparator that supplies a transmission signal to each of the i-th transmission/reception modules and divides, combines, and compares i×4 reception signals output from each of the i-th transmission/reception modules to form a plurality of composite beams,
the i-th transmission/reception module is provided with a function of switching between a first mode for outputting the first and second reception signals and a second mode for outputting the third and fourth reception signals at the reception system output terminals of the first to fourth antenna elements,
The distribution/combination comparator is
incorporating a processing system for the first mode and a processing system for the second mode;
a processing system in the first mode inputting the first and second received signals and comparing and combining the first and second received signals so as to form a composite beam of all antenna elements;
A signal processing method for an electronically scanned antenna, in which the third and fourth received signals are input to a processing system in the second mode, and compared and synthesized so as to form a plurality of beams into which all antenna elements are divided.

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