RU2730120C1 - Method of constructing an active phased antenna array - Google Patents

Abstract

FIELD: antenna equipment.SUBSTANCE: invention relates to antenna engineering and is intended for construction of active phased antenna arrays (APAA) for radio communication and radar systems. Antenna elements are placed on front panels of multichannel transceiving modules in nodes of rectangular or triangular grid, with pitch along vertical and horizontal, determined by required scanning sector, respectively, in vertical and horizontal planes, connecting each radiator to input / output of one of channels of multichannel transceiving module, forming an antenna band of an active phased antenna array from multichannel transceiving modules, by placing them adjacent to each other such that the surfaces of their front panels are located in one plane, and the distance between the emitters is kept constant in the vertical and horizontal planes, wherein the front panels of the transceiving modules function as a screen, forming a heterodyne signal and distributing it to multichannel transceiving modules, in transmitting mode generating a beam pattern with a given shape by setting phase and amplitude ratios of the transmitted signal in the channels of the transceiving modules, receiving mode amplifies received signals, frequency-converted, sampling signal at intermediate frequency from output of receiving part of each channel of transceiving module and generating from the obtained samples the required number of beams of the receiving beam pattern by weight summation of signals in the digital beam formation system. According to the invention, generating a reference signal with a fixed frequency and distributing it to multichannel transceiving modules, in each transceiving module using a reference signal in a transmission mode, generating a transmitted signal in the built-in signal former and distributing it to channels of that module, wherein transmitting signal is amplified in transmitting part of each channel by built-in power amplifier, in each transceiving module by means of reference signal sampling signal is generated, which is used for discretisation of signal from output of receiving part of each channel of transceiving module, wherein the number of types of generated transmitted signals in different multi-channel transceiving modules is determined based on the required number of generated beam pattern.EFFECT: technical result is possibility of APAA separation into several subarrays, which form independent transmitting BP with electronic scanning.1 cl, 6 dwg

Description

The invention relates to antenna technology, namely, to methods for constructing active phased antenna arrays (AFAR) and can be used to construct AFAR radio communication and radar systems.

A known method of constructing a phased antenna array (PAR) [1 -p. 661, fig. 13.44, Handbook of Radar. / Ed. M.I. Skolnik. M .: Technosphere. 2014 book 1. - 672 p.], In which N horizontal lines of emitters are installed, one above the other, and N transceivers, while each line of emitters contains M emitters combined through a power divider, which in the receive mode works as a power adder. The input-output of the transceiver is connected to the input of the power divider. The output of the shaper of the probing signal is connected to a power divider according to the number of lines of emitters, a phase shifter is installed in each transceiver. The input of the receiving part of the transceiver is connected to the output of its transmitting part through a protection device and a circulator, and the output is connected to an analog-to-digital converter.

The disadvantage of this method is the presence of losses of the received signal in the adders of passive lines of emitters. These losses are introduced in front of the low noise amplifier (LNA), and therefore cause a deterioration in the sensitivity of the AFAR in the receive mode.

A known method of constructing a phased antenna array [2 - p. 25, Fig. 2.3, 2.5 Kuzmin S.Z. Digital radar. Introduction to the theory. Kiev. 2000 - 420 p.], In which the antenna elements are combined into passive linear subarrays, inside which each antenna element is connected through a phase shifter with a subarray adder, which is used in the transmission mode as a power divider, while in the transmission mode a probe signal is generated in the unit signal formation, amplify it in a power amplifier, divide it by the number of sublattices, distribute it to subarrays using a distribution system and set the direction of the transmitting beam using subarray phase shifters. In the reception mode, the received signals in the sublattices are combined with the help of sublattice adders, they are amplified, converted in frequency, sampling is performed, and a receiving directional pattern (DP) is formed in the digital beamforming system by the weight summation of signals from the outputs of the sublattices. In this case, the conversion to digital form is performed by quadrature analog-to-digital converters at zero frequency, and an antenna switch is used to decouple the receiving and transmitting parts.

The disadvantage of this method is the use of passive linear subarrays in the antenna array, the antenna elements of which are combined using power adders, which in the receiving mode degrades the sensitivity of the receiving part of the AFAR, and in the transmit mode reduces the power of the emitted signal. Taking into account that the dissipative losses in the adders are, depending on the number of antenna elements and the used frequency range, from 0.5 to 1.5 dB, this causes an increase in the noise figure of the receiving part by an amount from 0.5 to 1.5 dB ... In the transmission mode, the adder works as a power divider, and the losses in it reduce the power of the emitted signal by an amount from 0.5 to 1.5 dB.

The closest in technical essence to the invention is a method for constructing an active phased antenna array [3 - RF patent No. 2697194, "Method for constructing an active phased antenna array", IPC G01S 13/00, publ. 08/13/2019], taken as a prototype, in which antenna elements are used to emit and receive signals, while in the transmission mode the transmitted signal is generated, amplified in the power amplifier, distributed using a distribution system, in the transmission mode the direction of the transmitting beam is set using phase shifters, in the receiving mode, the received signals are amplified, converted in frequency, the signals are sampled, and the receiving directional pattern is formed by weighted summation of signals in the digital beamforming system.

Antenna elements are placed on the front panels of multichannel transceiver modules at the nodes of a rectangular or triangular grid, with a vertical and horizontal step determined by the required scanning sector, respectively, in the vertical and horizontal planes, each emitter is connected with a communication line of minimum length with the input-output of one of the channels of a multichannel transceiver module, while a phase shifter is installed in the transmitting part of each channel, and a circulator is used to decouple the receiving and transmitting parts of the channel, an antenna sheet of an active phased antenna array is formed from multichannel transceiver modules, installing them next to each other so that the surfaces of their front panels were located in the same plane, and the distance between the emitters remained unchanged in the vertical and horizontal planes, while the front panels of the transceiver modules function as a screen, form the local oscillator signal, signal clock sampling frequency, and distribute them to multichannel transceiver modules, in the transmission mode, a transmitting beam with a given shape is formed by setting the phase and amplitude ratios of the transmitted signal in the channels of the transceiver modules, in the receiving mode, the signal is sampled at an intermediate frequency from the output of the receiving part of each channel of the transceiver module and form the required number of beams of the receiving directional pattern from the received samples.

The disadvantages of the prototype include:

- the impossibility of forming several transmitting LTOs in AFAR, which is necessary, for example, in radio communication systems to ensure communication with several points simultaneously;

- large losses of the transmitted signal in the AFAR devices during its transmission from the place of formation to the emitters. In this case, after formation, the transmitted signal is distributed to multichannel transceiver modules (TPM) through the distribution system, after which it is divided into TPM by the number of channels, etc. All of these circuits have losses, which reduces the power of the radiated signal.

The technical problem to be solved by the present invention is the formation of several transmitting directional patterns in the AFAR.

To solve this technical problem, a method for constructing an active phased antenna array is proposed, in which antenna elements are placed on the front panels of multichannel transceiver modules at the nodes of a rectangular or triangular grid, with a vertical and horizontal step determined by the required scanning sector, respectively, in the vertical and horizontal planes , connect each emitter to the input-output of one of the channels of the multichannel transceiver module, form the antenna fabric of the active phased antenna array from the multichannel transceiver modules, installing them next to each other so that the surfaces of their front panels are located in the same plane, and the distance between emitters remained unchanged in the vertical and horizontal planes, while the front panels of the transceiver modules perform the function of a screen, generate a local oscillator signal and distribute it to multichannel transceiver m Modules, in the transmission mode, form a transmitting directional pattern with a given shape by setting the phase and amplitude relationships of the transmitted signal in the channels of the transceiver modules, in the receiving mode they amplify the received signals, convert in frequency, perform sampling of the signal at an intermediate frequency from the output of the receiving part of each channel of the transceiver module and the required number of beams of the receiving directional pattern is formed from the received samples by the weight summation of the signals in the digital beamforming system.

According to the invention, a reference signal with a fixed frequency is generated and distributed to multichannel transceiver modules, in each transceiver module using a reference signal in the transmission mode, a transmitted signal is generated in the built-in signal conditioner and distributed to the channels of this module, while the transmitted signal is amplified in the transmitting parts of each channel with a built-in power amplifier, in each transceiver module using a reference signal, a sampling signal is generated, which is used to sample the signal from the output of the receiving part of each channel of the transceiver module, while the number of types of transmitted signals generated in different multichannel transceiver modules is determined based on the required the number of generated transmitting directional patterns.

The technical result of the proposed method is the possibility of dividing the APAA into several sublattices that form independent transmitting patterns with electronic scanning.

A comparative analysis of the claimed method and the prototype shows that their difference is as follows:

- in the prototype, the transmitted signal and the sampling signal are formed in the signal generation unit, then they are distributed to all PPMs using a distribution system. With this arrangement, it is possible to form only one scanning transmitting pattern in the AFAR. While in the proposed method, the transmitted signal is formed in each transceiver module in the built-in signal shaper, which allows the APAR to be divided into several subarrays that form the transmitting pattern in different directions;

- in the prototype, after the formation of the transmitted signal, it is distributed to all PPMs using a distribution system. In this case, the transmitted signal is attenuated by the amount of losses in the distribution system and the radiated power is reduced. While in the proposed method the transmitted signal is amplified in each PPM channel using a built-in power amplifier, the losses in the distribution system do not affect the level of the transmitted signal. This provides, with the same power consumption, an increase in the power of the emitted signal in the proposed method compared to the prototype.

The combination of distinctive features and properties of the proposed method for constructing an active phased antenna array is not known from the literature, therefore it meets the criteria of novelty and inventive step.

FIG. 1 shows a block diagram of a device that implements the proposed method.

FIG. 2 shows a block diagram of a digital diagramming system.

FIG. 3 shows a block diagram of the control unit.

FIG. 4 shows a block diagram of the frequency converter.

FIG. 5 shows a block diagram of the control and digital signal processing module.

FIG. 6 shows a block diagram of the signal conditioner.

When implementing the proposed method, the following sequence of actions is performed:

- antenna elements are placed on the front panels of multichannel transceiver modules at the nodes of a rectangular or triangular grid, with a vertical and horizontal step determined by the required scanning sector, respectively, in the vertical and horizontal planes -1;

- connect each emitter with the input-output of one of the channels of the multichannel transceiver module - 2;

- form an antenna web of an active phased antenna array from multichannel transceiver modules, installing them next to each other so that the surfaces of their front panels are located in the same plane, and the distance between the radiators remains unchanged in the vertical and horizontal planes, while the front panels of the transceiver modules function as a screen - 3;

- generate a local oscillator signal and distribute it to multichannel transceiver modules, in the transmission mode form a transmitting radiation pattern with a given shape by setting the phase and amplitude ratios of the transmitted signal in the channels of transceiver modules - 4;

- in the receiving mode, the received signals are amplified, converted in frequency, the signal is sampled at an intermediate frequency from the output of the receiving part of each channel of the transceiver module and the required number of beams of the receiving directional pattern is formed from the received samples by the weight summation of signals in the digital beamforming system - 5;

- form a reference signal with a fixed frequency and distribute it to multichannel transceiver modules, in each transceiver module, using a reference signal in the transmission mode, form a transmitted signal in the built-in signal generator and distribute it to the channels of this module, while amplifying the transmitted signal in the transmitting part of each channels by the built-in power amplifier - 6;

- in each transceiver module, using a reference signal, a sampling signal is generated, which is used to sample the signal from the output of the receiving part of each channel of the transceiver module, while the number of types of transmitted signals generated in different multichannel transceiver modules is determined based on the required number of generated transmitting directional patterns - 7.

The implementation of the proposed method for constructing the AFAR is possible, for example, with the help of a device that includes (Fig. 1) N transceiver modules (PPM) 1, a control unit (CU) 2, the first control output of which is connected to the control input of the signal generation unit (BPS) 3, the second control output - to the control input of the digital diagramming system (SDSDO) 4 and N control outputs connected to the control inputs of all PPM 1, and the input is the AFAR control input. The outputs of the local oscillator signal Fget and the reference signal F _O BFS 3 are connected to the distribution system (PC) 5.

PC 5 has N outputs of the local oscillator signal Fget connected to the inputs of the local oscillator PPM 1 and N outputs of the reference signal F _O connected to the inputs of the reference signal PPM 1.

PPM 1 contains the first power divider (DM) 6 and a signal shaper (FS) 7, the inputs of which are, respectively, the heterodyne and reference input of the PPM 1, the control and digital signal processing module (MUTSOS) 8, the sampling input of which is connected to the output of the sampling signal Fd of the signal conditioner 7, and the control input is the control input of the PPM 1. The control input of the signal conditioner 7 is connected to one of the control outputs of the MUTSOS 8.

PPM 1 also contains M channels, each of which contains a series-connected phase shifter (FV) 9, the input of which is the input of the channel and is connected to one of the outputs of the transmitted signal of the signal shaper 7, and the control input is the first control input of the channel and is connected to one of the control outputs MUTSOS 8, power amplifier (PA) 10, circulator (C) 11 and antenna element (AE) 12.

The output of the circulator 11 is connected in series with a low noise amplifier (LNA) 13, a frequency converter (IF) 14, the heterodyne input of which is the heterodyne input of the channel and is connected to one of the M outputs of the first power divider 6, the control input is the second control input of the channel and is connected to one of the control outputs of MUTsOS 8, and the output is the output of the intermediate frequency (IF) channel and is connected to one of the inputs of the IF MUTsOS 8.

The data output MUTSOS 8 is the data output of the PPM 1 and is connected to one of the N data inputs of the SDSDO 4, the control input of the MUTSOS 8 is the control input of the PPM 1 and is connected to one of the N control outputs of the BU 2.

SDSDO 4 (Fig. 2) has K shapers 15 according to the number of formed beams, each of which contains TV channels, while the inputs of the i-th channels (i = 1 ... N) in the shapers 15 are combined. Each channel of the shaper 15 contains a multiplier 16, the first input of which is the input of the channel, the output of the read-only memory (ROM) 17 is connected to the second input, and the output of the multiplier 16 is the output of the channel and is connected to one of the N inputs of the digital adder 18, the output of which is connected to one of the K inputs of the interface (I) 19. The output of interface 19 is the output of SDSD 4 and the entire device. SDSDO 4 can be performed, depending on the number of PPM 1 and the number of beams K, in the form of one or more programmable logic integrated circuits (FPGA).

The control unit (CU) 2 (Fig. 3) has a control device (CU) 20, the input of which is the control input of the AFAR. CU 20 also has 3 + N control outputs, which are control outputs of CU 2. CU 20 can be made, depending on the number of PPM 1 and the number of beams K, in the form of one or more programmable logic integrated circuits (FPGA).

IF 14 (figure 4) is a series-connected first mixer (SM) 21, the input of which is the input of the IF 14, and the heterodyne input is the heterodyne input of the IF 14 and the intermediate frequency amplifier (IF) 22, the output of which is the output of the intermediate frequency (IF ) PRF 14, and the control input is the control input of PRF 14.

MUTsOS 8 (figure 5) includes M analog-to-digital converters (ADC) 23, the inputs of which are inputs of the IF MUTsOS 8, the inputs of the sampling signal are connected to the outputs of the second power divider (DM) 24, and the outputs are connected to the inputs of the control unit and processing (CUO) 25. The first, second and third control outputs CUO 25 are, respectively, the first, second and third control outputs of the CUO 8. The data output and the control input CUO 25 are, respectively, the data output and control input of the CUO 8. Input of the second the power divider 24 is the sampling input of the MUTCS 8.

BFS 3 consists of two frequency synthesizers that provide the formation of the local oscillator signal Fget and the reference signal Fo. This can be used, for example, synthesizers and amplifiers from [3 - pp. 142-143. Mini-Circuits. RF & Microwave components guide. 2010].

PC 5 is a power divider that splits the local oscillator signal Fget and the reference signal Fo to N outputs using power dividers [3 - pp. 136-140].

The signal shaper 7 contains (Fig. 6) a frequency synthesizer (MF) 25, the reference input of which is the reference input of the signal shaper 7, the control input is the control input of the signal shaper 7, and the sampling output is the sampling output of the signal shaper 7. The signal output of the frequency synthesizer 25 connected to the input of the second mixer 26, the heterodyne input of which is the heterodyne input of the signal conditioner 7, and the output is connected to the third power divider 27. The outputs of the third power divider 27 are the outputs of the signal conditioner 7.

AFAR works as follows.

In the transmission mode, in the frequency synthesizer 25 of the signal shaper 7, the transmitted signal PS is formed, which is transferred with the help of the second mixer 26 to the AFAR operating frequency range and is branched according to the number of PPM 1 channels in the third power divider 27. In the case of the formation of one transmitting pattern in all PPM 1 the same transmitted signals are formed. If it is necessary to simultaneously form several independent transmitting MDs available in the AFAR PPM 1 in the transmission mode are programmatically combined into sublattices, the number of which is equal to the number of formed MDs. In this case, different types of transmitted signals can be used in each sublattice.

AFAR forms the transmitting DP by setting the required phase relations in the PPM 1 by adjusting the phase shift of the PS transmitting signal in the phase shifters 9. If necessary, the amplitude distribution in the AFAR can be set by the appropriate choice of amplification in the power amplifiers of 10 different PPM 1 channels.

For the case of a flat rectangular APAR, in which one transmitting pattern is formed with the direction of the maximum ϕ, θ, respectively, in azimuth and elevation, the aperture of which contains N _x AE 12 installed along the X coordinate at a distance d _x , and N _y AE 12 installed along coordinates Y, at a distance d _y , DN F (ϕ, θ) is defined as [2 - p. 27-28]:

where A _xi , A _yi are the coefficients of the amplitude distribution along the X and Y coordinates, respectively;

ψ _хi , ψ _y - coefficients of phase distribution, presented in the form of phase shifts in phase shifters 9.

From the outputs of the phase shifters 9, the transmitted signal is amplified in the PA 10, and through the circulator 11 it enters the AE 12 and is radiated into space. After that, AFAR goes into reception mode.

In the case of dividing the APAR into L sublattices, in each sublattice, in accordance with formula (1), its own transmitting DP F _l (ϕ _l , θ _l ,) can be similarly formed, where ϕ _l and θ are the directions of the maximums of the transmitting DP, l = 1 ... L.

In the receiving mode, the received reflected signals from the output of each AE 12 in each PPM 1 pass through the circulator 11, amplified in the LNA 13, converted in frequency to the RFP 14 and represented as digital samples S _mn (t) using the ADC 23.

From the received digital samples, a receiving single or multi-beam pattern is formed by weight summation in the SDSD 4. The number of beams formed is determined by the purpose of the APAR and the number of transmitting patterns.

The counts of the i-th ray with the direction of the maximum ϕ _i , θ _i are calculated by multiplying the digital stream from each PPM 1 in multipliers 16 by the weighting factor W _mn (ϕ _i , θ _i ,) from the ROM 17 and summing in the digital adder 18. Directional diagram for the i-th receiving beam has the form

The generated samples K of the receiving beams from the outputs of the shapers 15 are fed to the interface 19, where they are serialized and transmitted to the AFAR output in the form of serial codes.

In the proposed method, due to the use of signal shapers 7 in each PPM 1, it is possible to programmatically divide the APAR in the transmission mode into subarrays that form independent transmitting patterns in different directions with different types of transmitted signals. If it is necessary to work with the maximum gain of the AFAR, all PPM 1 work synchronously and form one transmitting pattern.

In the proposed method, power amplifiers 10 are installed in each channel of a multichannel PPM, their output through the circulator 11 is connected to the antenna element 12. While in the prototype, the signal from the output of the power amplifier enters the distribution system, where it is attenuated by an amount from 1 to 5 dB depending on the design and the number of PPMs. Accordingly, in the prototype, a signal with a reduced power is emitted over the air due to losses in the distribution system. Thus, in the proposed method, the loss of the transmitted signal is lower by 1 to 5 dB than in the prototype.

The efficiency of the proposed method was tested on a device model (Fig. 1). Tests have shown the coincidence of the obtained characteristics with the calculated ones.

Claims (1)

A method for constructing an active phased antenna array, in which antenna elements are placed on the front panels of multichannel transceiver modules in the nodes of a rectangular or triangular grid, with a vertical and horizontal step determined by the required scanning sector, respectively, in the vertical and horizontal planes, each emitter is connected to the input -the output of one of the channels of the multichannel transceiver module, the antenna fabric of the active phased antenna array is formed from the multichannel transceiver modules, installing them next to each other so that the surfaces of their front panels are located in the same plane, and the distance between the emitters remains constant in the vertical and horizontal planes, while the front panels of the transceiver modules perform the function of the screen, generate the local oscillator signal and distribute it to the multichannel transceiver modules, in the transmission mode form the transmitting diagram directionality with a given shape by setting the phase and amplitude ratios of the transmitted signal in the channels of the transceiver modules, in the receiving mode the received signals are amplified, converted in frequency, the signal is sampled at an intermediate frequency from the output of the receiving part of each channel of the transceiver module and the required number of beams is formed from the received samples of the receiving directional pattern by weighting the summation of signals in a digital beamforming system, characterized in that a reference signal is generated with a fixed frequency and distributed to multichannel transceiver modules, in each transceiver module using the reference signal in the transmission mode, a transmitted signal is formed in the built-in signal conditioner and distributed it to the channels of this module, while amplifying the transmitted signal in the transmitting part of each channel with a built-in power amplifier, in each transceiving module using a reference signal, it is formed with sampling ignal, which is used for sampling the signal from the output of the receiving part of each channel of the transceiver module, while the number of types of generated transmitted signals in different multichannel transceiver modules is determined based on the required number of generated transmitting directional patterns.

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