CN114928384A - Staggered subarray mixed beam forming system and method for simultaneously forming two independent beams - Google Patents
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Abstract
The application provides a staggered subarray mixed beam forming system and a method for simultaneously forming two independent beams, wherein the system comprises: a receiving circuit and a transmitting circuit; the receiving circuit and the transmitting circuit jointly comprise a system array antenna and a digital signal processing module; the system array antenna comprises M groups of subarray antenna units formed by K unit antennas, and the structures of each group of subarray antenna units are the same; the digital signal processing module comprises a beam forming weight calculation module, a receiving beam forming module and a transmitting beam forming module. According to the method, the distance and the direction of grating lobes are changed by changing the carrier frequency and setting a proper phased array subarray analog phase shift value according to the directions of two expected beams, and the positions of the main lobe and the grating lobes of the subarray are utilized to simultaneously form two independently directed highest gain beams by matching with digital weighting output by the subarray.
Description
Technical Field
The present application relates to the field of digital array phased array system beam forming, and more particularly, to a staggered sub-array hybrid beam forming system and a method for simultaneously forming two independent beams.
Background
Active analog phased array antennas have been widely used in radio systems, and have the advantages of fast beam switching and flexible beam pattern control. However, if independent multi-beam is needed to be formed simultaneously, a plurality of groups of analog phase shifters are needed, and the structure is complex. The unit-level Digital beam forming antenna, especially the receiving antenna, can conveniently form a plurality of arbitrary beams simultaneously through a plurality of groups of weight coefficients in a Digital domain, and has no gain loss, but needs radio frequency transceiving channels (generally adopting a superheterodyne structure, including circuits such as amplification, mixing and filtering, etc.), a high-speed Digital-to-Analog Converter (DAC) and an Analog-to-Digital Converter (ADC), as well as a frequency synthesizer source and a large-scale local oscillator power synthesis and distribution network, which are the same in number as the unit antenna. The sub-array mixed beam forming is a balance between active analog phased array beam forming and unit-level digital beam forming, the complexity and the implementation cost of the system are reduced, independent multiple beams can be formed at the same time, but the performance such as the gain of simultaneous multiple beams formed by the existing system is reduced.
The phased array subarrays are divided into two types, namely local subarrays and staggered subarrays. In the local subarray structure, the antenna elements of each subarray are adjacent to each other. The spacing between array elements in the sub-array is generally slightly larger than half wavelength, so that grating lobes do not appear in the scanning range, and when a plurality of beams need to be formed simultaneously, part of the sub-array is used for forming the beams, so that the beam gain cannot be maximized. The antenna elements of each sub-array of the staggered sub-array structure are uniformly distributed on the whole array, and the sub-arrays are staggered with each other. The structure can utilize the grating lobe characteristic of the subarray to simultaneously form a plurality of maximum gain beams which fully utilize the array elements of the whole array in the direction of the main lobe of the subarray and the direction of the grating lobe, but the different directional beams have the limit relation of the grating lobe spacing, and complete independent pointing cannot be realized.
Disclosure of Invention
The application provides a staggered subarray mixed beam forming system and a method for simultaneously forming two independent beams, which can be used for solving the technical problem that the two independent beams cannot realize maximum gain in the prior art.
In a first aspect, the present application provides an interleaved subarray hybrid beamforming system, the system comprising: receiving circuit and transmitting circuit
The receiving circuit and the transmitting circuit jointly comprise a system array antenna and a digital signal processing module;
the system array antenna comprises M groups of subarray antenna units formed by K unit antennas, and the structures of each group of subarray antenna units are the same;
the digital signal processing module comprises a beam forming weight calculation module, a receiving beam forming module and a transmitting beam forming module.
With reference to the first aspect, in an implementation manner of the first aspect, the receiving circuit includes, in order, a system array antenna, a phase shifter, a radio frequency channel receiver, a narrowband ADC, a down-conversion circuit, and a digital signal processing module;
the transmitting circuit sequentially comprises a digital signal processing module, a signal generator, an up-conversion circuit, a narrow-band DAC, a radio frequency channel transmitter and a system array antenna.
In a second aspect, the present application provides a method for simultaneous formation of two independent beams, the method being implemented by the interleaved subarray hybrid beamforming system of claims 1 to 2, the method comprising:
the weight calculation module determines the carrier frequency of the system according to the directions of the two expected beams; determining an analog weight coefficient and a digital weight coefficient according to the directions and carrier frequencies of the two expected beams;
the transmitting beam forming module controls a system array antenna in a transmitting circuit to transmit beams according to the analog weight coefficient and the digital weight coefficient;
and the receiving beam forming module controls a system array antenna in the receiving circuit to receive beams according to the analog weight coefficient and the digital weight coefficient.
With reference to the second aspect, in an implementable manner of the second aspect, the carrier frequency of the system is determined by:
where d is the array element spacing, c is the speed of light, and the two desired beams are each directed at θ 1 ,θ 2 And l is a two-point theta for selecting a desired beam 2 Natural number, f, matched to grating lobe of subarray directional diagram i Being carrier frequency, carrier frequency f i By local oscillator signals f i -f I Is implemented.
With reference to the second aspect, in an implementable manner of the second aspect, the M (M-1, 2, …, M) th sub-array is required to form
Point of direction
When the wave beam is formed, the analog weight coefficient corresponding to the sub-array is determined by adopting the following method:
in the formula (I), the compound is shown in the specification,
and the simulation weight coefficients corresponding to the sub-arrays.
With reference to the second aspect, in an implementable manner of the second aspect, the digital weight coefficient is determined by:
wherein, w d,m,1 (θ 1 ) And w d,m,2 (θ 2 ) The digital weighting coefficients of the m-th sub-arrays of the two desired beams, respectively.
With reference to the second aspect, in an implementation manner of the second aspect, the controlling, by a transmit beamforming module, a system array antenna in a transmit circuit to perform beam transmission according to the analog weight coefficient and the digital weight coefficient includes:
the transmitting beam forming module switches the T/R to a transmitting state and generates a baseband signal;
carrying out weighted summation by using two groups of digital weight coefficients to obtain a path of output, and up-converting data into frequency f I The digital intermediate frequency signal is filtered and output, digital-to-analog conversion is carried out, and the local oscillation signal f is adjusted 0 -f I The frequency f is obtained by up-conversion filtering 0 The analog radio frequency signal of (1);
and the signals are shunted through a power distribution network, analog weighting is carried out, and the signals are radiated to an airspace by a system array antenna to realize beam emission.
With reference to the second aspect, in an implementation manner of the second aspect, the controlling, by the receive beamforming module, a system array antenna in a receiving circuit to perform beam receiving according to the analog weight coefficient and the digital weight coefficient includes:
the receiving beam forming module switches the T/R to a receiving state, performs amplification filtering and analog phase shifter weighting on the radio frequency signals, and synthesizes K paths of outputs in the same group to obtain M paths of sub-array output analog signals;
adjusting local oscillator signal f 0 -f I And down-conversion and intermediate-frequency filtering are carried out to obtain the frequency f I Performing analog-to-digital conversion and digital down-conversion filtering processing on the intermediate-frequency signal to obtain M baseband data;
and weighting the two groups of digital weighting coefficients respectively to obtain two groups of independent receiving beam forming data so as to realize receiving beam forming.
Compared with the prior art, the method has the following advantages:
the staggered sub-array mixed beam forming system does not need two groups of phased array phase shifters and array element level full digital processing, and beam forming of two independently-directed highest gain beams is achieved. On the premise of the requirement of two simultaneous independent beams, the complexity and the cost of the conventional implementation scheme are effectively reduced.
The staggered subarray beam hybrid forming system can effectively solve the problem that the whole antenna array surface resource cannot be completely utilized because each beam only uses a part of subarrays under the condition that a plurality of beams are formed simultaneously in the existing local subarray beam hybrid forming system. Although a subarray structure is adopted, the two beams formed by the system have the maximum array gain, and the beam pointing directions can be independently configured under the condition that a certain interval requirement is met.
The application provides a scheme for adjusting the working frequency point of a staggered subarray wave beam hybrid forming system by changing the working frequency, realizing the position control of grating lobes and further reducing the mutual limitation of the pointing directions of two independent wave beams. The working frequency point can be selected according to the pointing angles of two expected beams, and the digital weighted values of the analog phased array subarrays and the subarrays are determined, so that simultaneous dual beams are realized.
Drawings
Fig. 1 is a schematic diagram of an interleaved subarray antenna array according to an embodiment of the present application;
fig. 2 is a schematic diagram illustrating distribution of grating lobes of a subarray directional diagram when the interleaved subarray hybrid beam forming system provided in the embodiment of the present application operates at the highest frequency and the lowest frequency;
fig. 3 is a partial matrix and full matrix directional diagram provided in an embodiment of the present application;
FIG. 3(a) shows a single phased array subarray directional diagram, and FIG. 3(b) shows a desired direction θ 1 At 30 DEG and theta 2 -30 ° of full array pattern;
fig. 4 is a block diagram of an interleaved subarray hybrid beamforming system according to an embodiment of the present application.
Detailed Description
To make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.
The staggered sub-array mixed beam forming system adopts a sub-array phased array structure with lower cost to simultaneously form two independent beams. According to the pointing directions of two expected beams, the distance and pointing direction of grating lobes are changed by changing carrier frequency and setting a proper phased array subarray analog phase shift value, digital weighting output by the subarray is matched, and two independently pointed highest gain beams are formed at the same time by using the positions of a main lobe and the grating lobes of the subarray.
The system provided by the application comprises: a receiving circuit and a transmitting circuit.
The receiving circuit and the transmitting circuit jointly comprise a system array antenna and a digital signal processing module.
The system array antenna comprises M groups of subarray antenna units formed by K unit antennas, and the structures of each group of subarray antenna units are the same. Each sub-array includes a wideband phase shifter and a power distribution/combining network.
The digital signal processing module comprises a beam forming weight calculation module, a receiving beam forming module and a transmitting beam forming module.
Correspondingly, the receiving circuit sequentially comprises a system array antenna, a phase shifter, a radio frequency channel receiver, a narrow-band ADC, a down-conversion circuit and a digital signal processing module. The receiving circuit completes the work of radio frequency signal receiving, amplifying and filtering, analog phase shifter weighting, first-stage or second-stage mixing and filtering amplification, intermediate frequency filtering, analog-to-digital conversion, digital down-conversion filtering processing and the like to obtain baseband signals, and weighting and summing different subarray digital weighting coefficients on the baseband signals to obtain two groups of independent beam forming data.
The transmitting circuit sequentially comprises a digital signal processing module, a signal generator, an up-conversion circuit, a narrow-band DAC, a radio frequency channel transmitter and a system array antenna. The transmitting circuit completes the generation of baseband signals, digital weighting, digital up-conversion filtering, digital-to-analog conversion, intermediate frequency filtering, primary or secondary mixing filtering amplification, analog phase shifter weighting, amplification filtering, radio frequency signal transmission and the like, and realizes dual-beam signal transmission.
The application provides a method for simultaneously forming two independent beams, which comprises the following steps:
in step S1, the weight calculation module determines the carrier frequency of the system according to the directions of the two desired beams. And determines the analog weight coefficients and the digital weight coefficients based on the carrier frequencies and the pointing directions of the two desired beams.
The carrier frequency of the system is determined by adopting the following method:
wherein d is the array element spacing, c is the speed of light, and the two desired beams are respectively oriented at theta 1 ,θ 2 L is a second pointing direction theta for selecting a desired beam 2 Natural number, f, matched to grating lobe of subarray directional diagram i Is the carrier frequency.
Carrier frequency f in practical system implementation i By local oscillator signals f i -f I Is realized by a change of the intermediate frequency f I And (5) fixing.
The simulation weight coefficient corresponding to the subarray is determined by adopting the following method:
in the formula (I), the compound is shown in the specification,
and the simulation weight coefficients corresponding to the sub-arrays.
The digital weight coefficients are determined by:
wherein, w d,m,1 (θ 1 ) And w d,m,2 (θ 2 ) The digital weighting coefficients of the m-th sub-arrays of the two desired beams, respectively.
And step S2, the transmit beam forming module controls the system array antenna in the transmit circuit to transmit a beam according to the analog weight coefficient and the digital weight coefficient.
Specifically, the transmission beam forming module switches the T/R to a transmission state and generates a baseband signal.
Carrying out weighted summation by using two groups of digital weight coefficients to obtain a path of output, and up-converting data into frequency f I The digital intermediate frequency signal is filtered and output, digital-to-analog conversion is carried out, and the local oscillation signal f is adjusted 0 -f I The frequency f is obtained by up-conversion filtering 0 The analog radio frequency signal of (1).
And the signals are branched through a power distribution network, analog weighting is carried out, and the signals are radiated to an airspace by a system array antenna to realize beam emission.
In step S3, the receive beam forming module controls the system array antenna in the receiving circuit to receive beams according to the analog weight coefficient and the digital weight coefficient.
Specifically, the receiving beam forming module switches the T/R to a receiving state, performs amplification filtering and analog phase shifter weighting on the radio frequency signal, and synthesizes the same group of K outputs to obtain M sub-array output analog signals.
Adjusting local oscillator signal f 0 -f I And down-conversion and intermediate frequency filtering are carried out to obtain the frequency f I And performing analog-to-digital conversion and digital down-conversion filtering processing on the intermediate-frequency signal to obtain M baseband data.
And weighting the two groups of digital weighting coefficients respectively to obtain two groups of independent receiving beam forming data so as to realize receiving beam forming.
To further illustrate the feasibility of embodiments of the present application, the following describes the principles of interleaved subarray multi-beamforming provided by the present application.
Consider an interleaved linear array of M sets of K element sub-arrays, as shown in fig. 4. When the M (M is 1,2, …, M) th sub-array is required to form a pointing direction
When the beam is in time, the sub-array simulates weight coefficients
Can be calculated by the following formula:
corresponding subarray directional diagram
Can be expressed as:
wherein d is the array element spacing, c is the speed of light, f 0 The current carrier frequency. If all M sub-arrays use the same analog weight coefficient, the full array pattern of the ith beam (i ═ 1,2, …)
Can be expressed as:
wherein the direction is
The digital weight coefficient of the m-th sub-array corresponding to the ith beam of (1)
Can be calculated by the following formula:
when observing the formula (2), it can be found that
When the number is an integer, the subarray directional diagram has a peak value, and the peak value position of the subarray directional diagram
And the direction pointed by the subarray directional diagram
The following relationship is satisfied:
according to the value range of the sine function, the value range can be obtained
Namely that
As long as
When the subarray directional diagram of the formula (2) has grating lobes, and the grating lobe spacing is
In addition, in the case of the present invention,
the direction of the main lobe is pointed to,
in the ith grating lobe direction. When the temperature is higher than the set temperature
Time, i.e. full array beam pointing
Selecting the first of the subarray directional diagrams i Full array directional diagram of individual grating lobe direction, equation (3)
It can be rewritten as:
then, when
When the signal is equal to l', the full array directional diagram has a peak value; when in
When the measured time is longer than l',
thus the digital weight factor
Can suppress the direction of removal as
The main lobe or grating lobe of the other subarray pattern.
It should be noted that, in the present application, the array can realize the simultaneous independent dual-beam formation only when the difference between the sine values of the pointing angles of the two beams is larger than the minimum beam interval.
The analytic relationship between the two beam pointing selection ranges and the relative bandwidths is analyzed below. When the first beam is pointed at theta 1 When determined, the second beam is directed to theta 2 The wave beam can independently select any angle, and the working bandwidth B of the whole system needs to meet certain conditions. Let f 0 Is the wavelength lambda 0 The corresponding system working center frequency and the array element spacing are fixed as d ═ lambda 0 And/2, the system relative bandwidth δ can be expressed as:
at this time, the selectable range of the system operating frequency can be expressed as f L ,f H ]＝[f 0 (1-0.5δ),f 0 (1+0.5δ)]. Observation formulas (A), (B)5) The grating lobe spacing Δ d ═ c/Mdf was found i L is inversely proportional to the operating frequency and the position of the grating lobes changes as the operating frequency changes. Thus, an appropriate f can be selected i To ensure that the second beam is directed at theta 2 The second beam is just coincided with one of the grating lobes of the frequency, and the area enclosed by the grating lobe of the highest frequency and the grating lobe of the lowest frequency is the selectable area pointed by the second beam.
When the working frequency is the highest and the lowest, the analog weight beam is pointed to theta 1 The main and grating lobe distributions of the simulated weight factors are shown in fig. 2. Highest frequency grating lobe pointing direction L fH,l And lowest frequency grating lobe pointing direction L fL,l Can be expressed as:
when l is a positive integer, the grating lobe on the right side of the main lobe is represented; when l takes a negative integer, the grating lobe on the left side of the main lobe is represented. It can be found that when the second grating lobe of the highest frequency and the first grating lobe of the lowest frequency satisfy the following condition:
the selectable angular coverage of the second beam may be maximized. The transformation formula (9) can obtain the value range of the relative bandwidth as delta is more than or equal to 2/3, which means that delta is min 2/3 is fixed regardless of the number of subarrays M and the size of the arrays. Therefore, when equation (9) is satisfied, the carrier frequencies f of the two beams can be easily determined i The grating lobe position is controlled to achieve that the second beam points in an arbitrary direction. At this time, carrier frequency f to be selected i And the grating lobe position l needs to satisfy:
at the same time, the minimum beam spacing may be through δ min 2/3 calculated:
while increasing δ may reduce the minimum beam spacing to some extent, it is not possible to completely overcome this limitation, and a larger δ may further increase the difficulty of system design and implementation.
As can be seen from equation (11), the minimum beam interval can be determined from δ. The array can realize independent double-beam formation at the same time only when the difference of sine values of the pointing angles of the two beams is larger than the minimum beam interval, namely the system has a certain blind area. However, when observing the sine function curve, the slope of the curve is maximum at the origin of the coordinate axis, gradually decreases toward both sides, and the cycle repeats. When the sine value dead zone is determined, the larger the slope of the sine function curve is, the smaller the corresponding angle dead zone is. Thus, when the antenna physical direction points at θ 0 ＝(θ 1 +θ 2 ) And when the pressure is/2, the angle blind area is the smallest.
When the beams of two independent beams are pointed at theta 1 ,θ 2 Determining and beam spacing greater than the minimum beam spacing, and comparing theta 1 Calculating the simulation weight as the beam pointing direction, pointing direction theta 2 And matching with the first grating lobe of the subarray directional diagram. Calculating to obtain proper f by taking the two angles as grating lobe peak angles by using the formula (5) i . And calculates the analog weight vector and the digital weight vector at that time.
Analog weight vector w a,m (θ 1 )：
w a,m (θ 1 )＝[w a,m,0 (θ 1 ),w a,m,1 (θ 1 ),...,w a,m,K-1 (θ 1 )] (12)
Wherein w a,m,k (θ 1 )＝exp{-j2πf i Mdksinθ 1 /c},(k＝0,1,...,K-1)。
Then, the digital weight vectors w of the two beams are respectively calculated d,m,1 (θ 1 ) And w d,m,2 (θ 2 )：
Wherein w d,m,i (θ i )＝exp{-j2πdf i msinθ i /c},(m＝0,1,...,M-1；i＝1,2)。
By using the characteristics of the digital weight coefficient, the maximum gain can be obtained in the expected direction while suppressing the gain in other peak directions, and simultaneous independent dual beam formation is realized.
The application is explained below with reference to specific embodiments, in which the center frequency f is 0 10GHz and array element spacing d lambda 0 0.0015m for/2, 2/3 for the relative bandwidth δ, and θ for each of the two desired beams 1 ＝30°，θ 2 At-30 °, different operating frequencies f can be obtained by selecting different l according to equation (10) i . In which the closest center frequency f is selected 0 Operating frequency f i 10GHz, where l is 2, i.e. the second beam is directed to theta 2 Matching with the 2 nd grating lobe at the right side of the main lobe of the subarray directional diagram, wherein the distance delta d between the grating lobes is | c/Mdf i 0.5. Respectively calculating to obtain the simulation weight vector w of each subarray according to the formula (12) and the formula (13) a,m (30°)：
w a,m (30°)＝[w a,m,0 (30°),w a,m,1 (30°),...,w a,m,K-1 (30°)] (14)
And the beam pointing direction theta 1 ,θ 2 Of the digital weight vector w d,m,1 (30 ℃) and w d,m,2 (-30°)：
Wherein, w d,m,1 ＝exp{-j2πdf i msin(30°)/c}，w d,m,2 ＝exp{-j2πdf i msin(-30°)/c}。
The system firstly works in a transmitting state, utilizes a transmitting beam digital circuit to carry out signal generation, digital weighting, up-conversion and analog weighting, and finally, the system is to be used for carrying out the following stepsThe signal is radiated to the space domain. Then, the system is switched to a receiving state, and a receiving beam digital circuit is used for data receiving, analog weighting, down-conversion, power synthesis and analog-to-digital conversion, wherein a corresponding subarray directional diagram is shown in fig. 3(a), and then a corresponding mth group of subarray output signals can be represented as
Using the digital weighting factors for two-stage beamforming with the corresponding array pattern as shown in fig. 3(b), the first beamforming output
Can be expressed as
A second beam forming output
Can be expressed as
Compared with the prior art, the method has the following advantages:
the staggered sub-array mixed beam forming system does not need two groups of phased array phase shifters and array element level full digital processing, and beam forming of two independently-directed highest gain beams is achieved. On the premise of the requirement of two simultaneous independent beams, the complexity and the cost of the conventional implementation scheme are effectively reduced.
The staggered subarray beam hybrid forming system can effectively solve the problem that the whole antenna array surface resource cannot be completely utilized because each beam only uses a part of subarrays under the condition that a plurality of beams are formed simultaneously in the existing local subarray beam hybrid forming system. Although the subarray structure is adopted, the two beams formed by the system have the maximum array gain, and the beam pointing directions can be configured independently under the condition that certain interval requirements are met.
The application provides a scheme for adjusting the working frequency point of a staggered subarray wave beam hybrid forming system by changing the working frequency, realizing the position control of grating lobes and further reducing the mutual limitation of the pointing directions of two independent wave beams. The working frequency point can be selected according to the pointing angles of two expected beams, and the digital weighted values of the analog phased array subarrays and the subarrays are determined, so that simultaneous dual beams are realized.
Those skilled in the art will clearly understand that the techniques in the embodiments of the present application may be implemented by way of software plus a required general hardware platform. Based on such understanding, the technical solutions in the embodiments of the present application may be essentially implemented or a part contributing to the prior art may be embodied in the form of a software product, which may be stored in a storage medium, such as a ROM/RAM, a magnetic disk, an optical disk, etc., and includes several instructions for enabling a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the method described in the embodiments or some parts of the embodiments of the present application.
The above-described embodiments of the present application do not limit the scope of the present application.
Claims (8)
1. An interleaved subarray hybrid beamforming system, the system comprising: a receiving circuit and a transmitting circuit;
the receiving circuit and the transmitting circuit jointly comprise a system array antenna and a digital signal processing module;
the system array antenna comprises M groups of subarray antenna units formed by K unit antennas, and the structures of each group of subarray antenna units are the same;
the digital signal processing module comprises a beam forming weight calculation module, a receiving beam forming module and a transmitting beam forming module.
2. The system of claim 1,
the receiving circuit sequentially comprises a system array antenna, a phase shifter, a radio frequency channel receiver, a narrow-band ADC, a down-conversion circuit and a digital signal processing module;
the transmitting circuit sequentially comprises a digital signal processing module, a signal generator, an up-conversion circuit, a narrow-band DAC, a radio frequency channel transmitter and a system array antenna.
3. A method for simultaneous formation of two independent beams, said method being implemented by the interleaved subarray hybrid beamforming system of claims 1 to 2, said method comprising:
the weight calculation module determines the carrier frequency of the system according to the directions of the two expected beams; determining an analog weight coefficient and a digital weight coefficient according to the directions and carrier frequencies of two expected beams;
the transmitting beam forming module controls a system array antenna in a transmitting circuit to transmit a beam according to the analog weight coefficient and the digital weight coefficient;
and the receiving beam forming module controls a system array antenna in the receiving circuit to receive beams according to the analog weight coefficient and the digital weight coefficient.
4. The method of claim 3, wherein the carrier frequency of the system is determined by:
where d is the array element spacing, c is the speed of light, and the two desired beams are each directed at θ 1 ,θ 2 And l is a two-point theta for selecting a desired beam 2 Natural number, f, matched to grating lobe of subarray directional diagram i Is the carrier frequency, carrier frequency f i By local oscillator signals f i -f I Is implemented.
5. A method as claimed in claim 3, characterized in that the M (M-1, 2, …, M) th sub-array is required to form a finger
When the wave beam is formed, the analog weight coefficient corresponding to the subarray is determined by adopting the following method:
in the formula (I), the compound is shown in the specification,
and the simulation weight coefficients corresponding to the sub-arrays.
6. The method of claim 3, wherein the digital weight coefficients are determined by:
wherein, w d,m,1 (θ 1 ) And w d,m,2 (θ 2 ) The digital weighting coefficients of the m-th sub-arrays of the two desired beams, respectively.
7. The method of claim 3, wherein the transmit beamforming module controls a system array antenna in a transmit circuit to transmit a beam according to the analog weight coefficients and the digital weight coefficients, comprising:
the transmitting beam forming module switches the T/R to a transmitting state and generates a baseband signal;
carrying out weighted summation by using two groups of digital weight coefficients to obtain a path of output, and up-converting data into frequency f I The digital intermediate frequency signal is filtered and output, digital-to-analog conversion is carried out, and the local oscillation signal f is adjusted 0 -f I The frequency f is obtained by up-conversion filtering 0 Analog radio frequency signals of (a);
and the signals are shunted through a power distribution network, analog weighting is carried out, and the signals are radiated to an airspace by a system array antenna to realize beam emission.
8. The method of claim 3, wherein the receiving beam forming module controls the system array antenna in the receiving circuit to perform beam receiving according to the analog weight coefficients and the digital weight coefficients, and comprises:
the receiving beam forming module switches the T/R to a receiving state, performs amplification filtering and analog phase shifter weighting on the radio frequency signals, and synthesizes K paths of outputs in the same group to obtain M paths of sub-array output analog signals;
adjusting local oscillator signal f 0 -f I And down-conversion and intermediate frequency filtering are carried out to obtain the frequency f I Performing analog-to-digital conversion and digital down-conversion filtering processing on the intermediate-frequency signal to obtain M baseband data;
and weighting the two groups of digital weighting coefficients respectively to obtain two groups of independent receiving beam forming data so as to realize receiving beam forming.
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| CN116545455A (en) * | 2023-07-04 | 2023-08-04 | 北京紫光青藤微***有限公司 | Method and device for adjusting energy dissipation of transmitter antenna and transmitter |
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