CN106848608B - Broadband mixed beam forming integrated antenna array - Google Patents

Abstract

The invention discloses a broadband hybrid beam-forming integrated antenna array, comprising a bidirectional phase-shifted transceiver array, an antenna array and a control and calibration unit; the bidirectional phase-shifted transceiver array includes at least one in-phase power division module and a plurality of bidirectional phase-shifted transceiver units. The in-phase power division module is used to divide a radio frequency signal into multiple radio frequency signals with equal and equal amplitude. Interchange into a phase-shifting module; the antenna array is used to radiate or receive signals from each radio frequency channel; one end of the control and calibration unit is used to control and calibrate the beamforming of the entire broadband hybrid beamforming integrated antenna array. Through the antenna array, the signal adjustment accuracy of each radio frequency channel is high, and accurate beam pointing with low sidelobe or no sidelobe can be formed in the horizontal plane, which is more conducive to simultaneous multi-user communication.

Description

Broadband Hybrid Beamforming Integrated Antenna Array

technical field

The invention relates to a wireless communication MIMO transceiver array, in particular to design a high-performance broadband hybrid beam forming integrated antenna array, which belongs to the communication multi-beam synthesis application technology.

Background technique

In the fifth-generation mobile communication, the data transmission speed between the user terminal and the base station will be greatly improved. Therefore, the single-channel communication system will be gradually eliminated, and the massive MIMO technology will become the key technology of the fifth-generation mobile communication system. . However, with the increase in the number of radio frequency channels and the number of antenna arrays, the hardware cost of communication base stations also increases significantly. All-digital beamforming base stations require that each antenna array corresponds to a complete radio frequency channel and digital baseband processing unit, so the hardware design is complicated. , and a large number of high-speed broadband analog-to-digital converters and high-speed digital processor units are not only expensive, but also have large power consumption and complex control, which are not conducive to large-scale integrated applications of base stations.

In contrast, the hybrid beamforming structure combining digital baseband domain precoding and RF analog domain shifting can effectively reduce digital hardware and system complexity, which has great advantages in practical applications. Among them, the phase adjustment of the RF signal directly on the RF link has the advantages of high response speed and accurate phase shifting accuracy. Compared with other phase shifting structures, the phase shifting on the RF link is undoubtedly the simplest structure. And will not introduce additional noise to deteriorate the signal-to-noise ratio of the radio frequency signal.

However, the phase-shifting module in the RF link often becomes the bottleneck restricting the development of the phase-shifting of the RF link. The traditional ESC phase shifter or digital phase shifter has the disadvantages of high price, low precision and narrow bandwidth; the vector modulator chip can It has high precision, but it is mostly used as a phase shifting module in low frequency band (less than 2.4GHz).

SUMMARY OF THE INVENTION

In order to overcome the deficiencies in the prior art, the present invention provides a high-performance broadband hybrid beamforming integrated antenna array capable of forming accurate beam pointing in a horizontal plane, which can be applied to a multi-user beamforming communication system.

In order to achieve the above purpose, the present invention discloses a broadband hybrid beamforming integrated antenna array, including a bidirectional phase-shifted transceiver array, an antenna array and a control and calibration unit; wherein:

The bidirectional phase-shifting transceiver array includes at least one in-phase power division module and a plurality of bidirectional phase-shifting transceiver units; the in-phase power division module includes multiple power dividers, which are used to divide one radio frequency signal into multiple radio frequency signals with equal and equal amplitude power; The phase-shifting transceiver unit includes a radio frequency transceiver front-end module and a quadrature synthesis phase-shift module that are electrically connected. The radio frequency transceiver front-end module is used to amplify the signal of the radio frequency channel, and the quadrature synthesis phase-shift module is used to adjust the phase and amplitude of the radio frequency channel. The radio frequency channel includes Receive and transmit signal channels; the antenna array includes multiple antenna units for radiating or receiving signals from each radio frequency channel; one end of the control and calibration unit is connected to each bidirectional phase-shifting transceiver unit, and the other end is connected to the baseband processing board for Control and calibrate the beamforming of the entire broadband hybrid beamforming integrated antenna array.

Further, the quadrature synthesis phase-shifting module includes a quadrature coupler, a first digitally controlled attenuator, a third radio frequency switch, a first transmission line transformer, a second numerically controlled attenuator, a fourth radio frequency switch, a second transmission line transformer and a power combiner. The input end of the quadrature coupler is connected to the in-phase power division module, and the 0-degree output end of the quadrature coupler is connected to the first input port of the power combiner through the first numerical control attenuator, the third radio frequency switch, and the first transmission line transformer in turn. The 90-degree output end of the quadrature coupler is connected to the second input port of the power combiner through the second numerically controlled attenuator, the fourth radio frequency switch, and the second transmission line transformer in turn, and the common port of the power combiner is connected to the radio frequency transceiver front end modules are connected.

Further, the quadrature coupler, digitally controlled attenuator, radio frequency switch, transmission line converter and power combiner all use broadband devices, the operating bandwidth range is 500MHz, and the center frequency coverage range is from 2.5GHz to 3.5GHz.

Further, the radio frequency transceiver front-end module includes a receive amplifying chain, a transmit amplifying chain, a first radio frequency switch and a second radio frequency switch; wherein, the common end of the first radio frequency switch is connected to the quadrature synthesis phase-shifting module, and the first radio frequency switch The transmit port is connected to the transmit port of the second radio frequency switch through a transmit amplification link; the common end of the second radio frequency switch is connected to the antenna array, and the receive port of the second radio frequency switch is connected to the receive port of the first radio frequency switch through a receive amplification link.

Further, the transmitting and amplifying chain includes a band-pass filter, a radio frequency amplifier and a power amplifier connected in sequence, and is used to filter and amplify the signal from the quadrature synthesis phase-shifting module when the radio frequency switch is turned on the transmitting port and then send it to the The antenna array radiates; the receiving and amplifying chain includes a low-noise amplifier, a band-pass filter and a radio frequency amplifier connected in sequence, which are used to amplify and filter the radio frequency signal received from the antenna array when the radio frequency switch is turned on the receiving port. into the quadrature synthesis phase-shifting module.

Further, the working frequency of the low noise amplifier is 50MHz to 4GHz, and the noise figure is 1.5dB; the working range of the radio frequency amplifier is 50MHz to 6GHz; the working range of the power amplifier is 200MHz to 6GHz; the performance requirement of the bandpass filter is within the passband. The insertion loss is less than 2dB, and the out-of-band spurious suppression reaches 30dB.

Further, the control and calibration unit includes a control part, a control interface and a read-only memory; the read-only memory is connected and communicated with the control part, the input end of the control part is connected to the baseband processing board, and the output end is connected to each bidirectional phase-shifting transceiver unit through the control interface; The control part can choose programmable logic device or single-chip microcomputer.

Further, a control word table is stored in the read-only memory, and the control word table includes pre-written phase and amplitude values as control words; It is written during initial phase calibration, including the initial phase value of each RF channel and the corresponding control of relative changes.

Further, when the baseband processing board performs initial phase calibration on each radio frequency channel, the initial amplitudes are adjusted to be the same for different radio frequency channels, and only the initial phases are different.

Further, the integrated antenna array adopts a linear array structure, including at least two groups of bidirectional phase-shifted transceiver sub-arrays and at least one group of antenna sub-arrays; the antenna array includes multiple antenna units and multiple power dividers, and the power divider The common end is connected to the antenna unit, and the split end of the power divider is connected to two bidirectional phase-shifted transceiver units in two adjacent two-way phase-shifted transceiver sub-arrays.

Further, the antenna unit adopts a broadband dipole antenna with a bandwidth range of 500MHz.

Beneficial effects:

(1) By adjusting the amplitude and phase of each channel of the bidirectional phase-shifting transceiver array, accurate beam pointing can be formed in the horizontal plane, and antenna side lobes can be suppressed; and the beam pointing accuracy can reach 0.31 degrees, and the coverage can be Up to 110 degrees; the conversion time between different angles can be completed within 3us through the quadrature synthesis phase-shifting module, which does not affect the normal transmission of communication symbols.

(2) The quadrature synthesis phase-shifting module can adjust the phase and amplitude of the signal separately. The phase accuracy of the RF signal adjustment in each channel can reach 1 degree, and the amplitude accuracy can reach 0.5dB; the generated low sidelobe or no sidelobe beams , in order to reduce sidelobe interference, which is more conducive to the function of multi-user simultaneous communication; and the quadrature synthesis phase-shifting module does not change the frequency of the radio frequency signal, so it has little effect on the phase noise of the radio frequency signal. And the phase noise does not affect the signal itself when adjusting the phase.

(3) Since the passive quadrature synthesis phase-shifting module is used to control the phase and amplitude changes of the radio frequency signal, the out-of-band spurs of the transmitted signal are very small, the noise introduced is also very small, and the signal-to-noise ratio of the radio frequency signal is not obvious. deterioration.

(4) Each device of the quadrature phase-shift synthesis module of the present invention adopts broadband devices, the working bandwidth can reach 500MHz, and the center frequency coverage is from 2.5GHz to 3.5GHz, which can cover part of the frequency band of the fifth generation mobile communication in the future, and solve the problem of The traditional structure has the disadvantages of narrow coverage and narrow working bandwidth.

(5) The baseband processing board can individually adjust the amplitude and phase of the signals in each radio frequency channel through the control part, and the control method is simple; the control and calibration unit adopts the automatic calibration method, and the initial phase can be automatically adjusted by the control part and the baseband processing board. Calibration reduces time and waste of resources.

(6) Two sets of two-way phase-shifted transceiver sub-arrays can respectively beamform the input RF signals, and connect different sub-arrays to the same group of antenna sub-arrays through a power divider to radiate two antenna sub-arrays on the same group of antenna sub-arrays. Incoherent beams are independent of each other and do not affect each other, so as to achieve the purpose of communicating with two users at the same time. Realize simultaneous multi-user communication.

(7) The antenna array adopts a linear array structure, which can increase the radiated power of the antenna, improve the directivity, and the array is simple, and the mutual coupling between the antennas is small; the antenna array adopts a broadband dipole antenna, which has a wide coverage and ensures the working frequency range. The electromagnetic wave signal inside can be transmitted and received, and the manufacturing cost is low.

(8) The integrated antenna array adopts a modular and innovative design, which realizes independent control of each bidirectional phase-shifting transceiver unit, and can still maintain a relatively accurate beam pointing even when some of the two-way phase-shifting transceiver units are damaged. Replace the damaged bidirectional phase-shifting transceiver unit to improve system stability and reduce maintenance costs; at the same time, the modular design also greatly reduces the cost of the system and the complexity of the circuit, while ensuring the phase-shifting accuracy and response speed. The out-of-band spurious amplitude is greatly reduced and the phase noise index of the signal is improved; the overall structure is simple, and the production and maintenance costs are also low.

Description of drawings

FIG. 1 is a schematic structural diagram of the hybrid beamforming integrated antenna array provided by the present invention.

FIG. 2 is a schematic diagram of a module of a bidirectional phase-shifting transceiver unit provided by the present invention.

FIG. 3 is a schematic diagram of the control and calibration unit provided by the present invention.

FIG. 4 is a schematic diagram of the principle of the quadrature phase-shift synthesis module.

Fig. 5 is the beam scanning test result of receiving state in the horizontal plane provided by the present invention

Fig. 6 is the beam scanning test result of the transmitting state in the horizontal plane provided by the present invention

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings.

As shown in FIG. 1 , Embodiment 1 discloses a high-performance broadband hybrid beamforming integrated antenna array, including a bidirectional phase-shifted transceiver array, an antenna array, and a control and calibration unit. in,

The bidirectional phase-shifted transceiver array includes an in-phase power division module 6 and a plurality of bidirectional phase-shifted transceiver units 1 . Each bidirectional phase-shifting transceiver unit 1 further includes a radio frequency transceiver front-end module 4 and a quadrature synthesis phase-shift module 5 which are connected to each other. The radio frequency transceiver front-end module 4 is used for amplifying the signal of the radio frequency channel, and the quadrature synthesis phase-shift module 5 is used for adjusting the radio frequency channel. The other end of the RF transceiver front-end module 4 is connected to the antenna array, the other end of the quadrature synthesis phase shifting module 5 is connected to the in-phase power division module 6, and the other end of the in-phase power division module 6 is connected to the control and calibration unit. The in-phase power division module 6 is used to divide the input radio frequency signal into N channels by in-phase power, and input them to each bidirectional phase-shifted transceiver unit respectively.

The antenna array 2 at least includes a plurality of antenna units 21 for radiating and receiving signals of each radio frequency channel, and the antenna array 2 may also include a power divider 22 for synthesizing different radio frequency signals of several sub-arrays into one.

The control and calibration unit 3 is used to control and calibrate the beamforming of the entire broadband hybrid beamforming integrated antenna array. As shown in FIG. 2 , the RF transceiver front-end module 4 is composed of a reception amplification chain, a transmission amplification chain, a first RF switch 41 and a second RF switch 42, and the RF switches 41 and 42 are used for switching between reception and transmission chains; The input end of the receiving amplification chain is connected to the output end of the second RF switch 42, and the output end is connected to the input end of the first RF switch 41; the input end of the transmitting amplification chain is connected to the output end of the first RF switch 41, and the output end is connected to the input end of the first RF switch 41; The input terminal of the second RF switch 42 . The receiving amplifying chain includes a low noise amplifier 43, a first bandpass filter 44 and a first radio frequency amplifier 45 connected in sequence; the transmitting amplifying chain includes a second bandpass filter 47, a second radio frequency amplifier 46 and a power amplifier 47 connected in sequence Amplifier 48.

The band-pass filter is used to filter out out-of-band interference, including the interference introduced by the impure spectrum of the radio frequency input of the base station itself. Other forms can also be used here, such as a combination of a high-pass filter and a low-pass filter; the radio frequency amplifier is used to offset the loss of the entire link, because the quadrature coupling module is passive, only the loss has no gain, so it needs to be in the A radio frequency amplifier is added to the radio frequency transceiver module in the latter stage. In the embodiment, the radio frequency transceiver front-end module 4 includes two radio frequency amplifiers, but the number of radio frequency amplifiers in practical applications is not limited to this. The number and model of radio frequency amplifiers depend on the required output power. The actual need can contain one or more radio frequency amplifiers;

The low-noise amplifier 43 is used for low-noise amplification of the received signal. Since the radio frequency signal received in the space is relatively weak, the noise of the amplifier itself will seriously interfere with the signal, while the noise of the low-noise amplifier itself is very small. Does not interfere with RF signals and can significantly reduce the signal-to-noise ratio.

The power amplifier 48 is used to amplify the transmitted signal at the final stage. Because the signal power required for transmission is relatively large, the linearity of ordinary radio frequency amplifiers cannot meet the requirements, while the linearity of the power amplifier is very excellent, which can complete high-power amplification output. .

The working state of the radio frequency transceiver front-end module 4 is divided into a transmitting state and a receiving state. In the receiving state, the first radio frequency switch 41 and the second radio frequency switch 42 are connected to the receiving end, and the low noise amplifier 43 and the band pass filter 44 are connected to the slave The radio frequency signal received by the antenna array 2 is subjected to low-noise amplification and filtering and then sent to the quadrature synthesis phase-shifting module 5; in the transmitting state, the No. 1 radio frequency switch 41 and No. 2 radio frequency switch 42 are placed on the transmitting end, and the band-pass filter 47 and power amplifier 48 amplify the signal output from the quadrature synthesis phase shifting module 5 and send it to the antenna array 2 for radiation.

As a preferred solution in the embodiment, the working range of the low noise amplifier 43 is 50MHz～4GHz, and the noise figure is 1.5dB; the working range of the power amplifier 48 is 200MHz～6GHz, and the 1dB compression point is 27dBm; The working range of the two RF amplifiers 46 is 50MHz to 6GHz, and the gain is 19dB, so as to meet the requirements of the communication base station for transmitting power and receiving sensitivity; the performance requirements of the bandpass filter are that the insertion loss in the passband is less than 2dB, and the out-of-band spurious suppression is up to 30dB.

In the Cartesian coordinate system, any vector signal can be decomposed into the sum of two orthogonal vectors, and after the decomposition of the two orthogonal vectors is attenuated and then synthesized, the two orthogonal vectors can be obtained. A vector of any angle and magnitude on a plane composed of vectors.

As shown in Figure 4, any vector in the figure corresponds to a radio frequency signal, the angle between it and the origin is the phase value, and the absolute value of the vector length is the amplitude value. For such a vector A, it can be decomposed into the sum of a vector B on a 0-degree coordinate axis and a vector C on a 90-degree coordinate axis, as shown in the vector corresponding to the dotted line in Figure 4. At this time, by adjusting the vector amplitudes on the 0-degree and 90-degree coordinate axes respectively, the amplitude and phase of the vector A are changing. However, the new RF vector only completes the change within the 90-degree range in Figure 4. If you want to complete the 360-degree change, you can switch the quadrant by introducing the structure of the RF switch and the transmission line converter. The principle is to use the inversion mechanism of the transmission line converter. The transmission line converter has two input ports, one output port, and the other is connected to the matching load port. Its function is that the phase of the RF signal input from port 1 is unchanged when it is output from the output port. , the phase of the RF signal input from port 2 changes 180 degrees when it is output from the output port. In FIG. 4, it can be considered as an operation of inverting the vector B and the vector C, respectively. The function of selecting two port inputs is completed by the RF switch, so that it can be extended to 360-degree phase adjustment. If it is only necessary to complete the phase-shifting operation, that is, keep the amplitude unchanged, and only change the phase, the new radio frequency vector A' only needs to change along the circle in Fig. 4 .

The quadrature synthesis phase shifting module 5 in the embodiment of FIG. 2 includes a quadrature coupler 51 , a first digitally controlled attenuator 52 , a second digitally controlled attenuator 55 , a third radio frequency switch 53 , a fourth radio frequency switch 56 , and a first transmission line transformer 54 , the second transmission line transformer 57 and the power combiner 58 .

The quadrature coupler 51 performs quadrature power division of the input signal, outputs an unphase-shifted signal from the 0-degree port, and outputs a 90-degree phase-shifted signal from the 90-degree port; the first digitally controlled attenuator 52 and the second digitally controlled attenuator 55 It is used to attenuate the amplitude and phase of the 0-degree signal and the 90-degree signal respectively; among them, the numerically controlled attenuator is used to adjust the amplitude, respectively adjusting the amplitude of the two orthogonal signals and then synthesizing them in phase is equivalent to adjusting the phase of the synthesized signal and amplitude; as a preferred solution in the embodiment, the digitally controlled attenuator can adopt a power attenuation device commonly used in the field, the maximum upper limit of the attenuation range of the first numerically controlled attenuator 52 and the second numerically controlled attenuator 55 is 31.5dB, and the attenuation interval is 0.5dB; of course, the actual application is not limited to this, and other attenuation intervals and other forms of digital attenuators can be used according to requirements.

The third RF switch 53 , the fourth RF switch 56 , the first transmission line transformer 54 and the second transmission line transformer 57 are used for switching between different quadrants. The two outputs of the third RF switch are respectively connected to the two inputs of the first transmission line transformer. When the signal input from the two input terminals enters the first transmission line transformer, there will be a difference of 180 degrees, and the third RF switch switches between the two input terminals of the first transmission line transformer, which corresponds to the inversion of the signal on the coordinate system. Phase operation; the corresponding fourth RF switch switches between the two input terminals of the second transmission line transformer to perform inversion operation on the other 90-degree signal.

Finally, the 0-degree signal and the 90-degree signal are synthesized in phase by the power combiner 58, thereby completing the adjustment of the phase of the corresponding radio frequency channel signal at any angle and amplitude within the range of 360 degrees. For example, when only the third RF switch is switched at the two input ends of the first transmission line transformer, it is equivalent to the synthesized signal being symmetrical about the Y axis. When only the fourth RF switch is switched at the two input ends of the second transmission line transformer, it is equivalent to The composite signal is symmetric about the X-axis.

Therefore, through the attenuation control of the first digitally controlled attenuator 52 and the second digitally controlled attenuator 55, a point of any angle and amplitude within the range of 0 to 90 degrees can be obtained; Switching can choose to perform normal phase or reverse phase operation on the signal, which is equivalent to performing quadrant selection on the composite vector, so as to complete the adjustment of the phase of the corresponding RF channel signal at any angle and amplitude within a 360-degree range.

The quadrature coupler, numerical control attenuator, radio frequency switch, transmission line changer and power combiner in the quadrature phase-shifting synthesis module 5 disclosed in the present invention all use broadband devices, the working bandwidth can reach 500MHz, and the center frequency coverage is from 2.5GHz to 3.5GHz, which can cover part of the frequency band of the fifth generation mobile communication in the future.

The power attenuation device with a range of 31.5dB and a step size of 0.5dB selected in the embodiment enables the quadrature synthesis phase-shifting module 5 to adjust the phase accuracy of the radio frequency signal in each channel to 1 degree, and the amplitude accuracy to 0.5dB; the generated Low side lobe or no side lobe beam to reduce side lobe interference, which is more conducive to the function of multi-user simultaneous communication. Moreover, the quadrature synthesis phase shifting module 5 does not change the frequency of the radio frequency signal, so it has little effect on the phase noise of the radio frequency signal, and does not affect the phase noise of the signal itself when adjusting the amplitude and phase of the radio frequency signal.

As shown in FIG. 3 , the control and calibration unit 3 in the embodiment includes a field programmable logic device 31 , a read-only memory 32 and a control interface 8 .

The field programmable logic device 31 is used to control the phase and amplitude of the radio frequency signal of each bidirectional phase-shifted transceiver unit in the entire integrated antenna array. In practical applications, the control part in the embodiment can not only select a field programmable logic device (FPGA) 31, but also select other programmable logic devices (PLD) or microcontrollers (MCU) according to requirements.

In the embodiment of FIG. 3 , the control and calibration unit 3 transmits the beam pointing command sent by the baseband processing board to the field programmable logic device 31 through the control interface 8 , and the field programmable logic device 31 converts the beam pointing command into a corresponding read-only memory address, and then read the phase value and amplitude value of each channel stored in the read-only memory 32 according to the corresponding address pair, return it to the field programmable logic device 31 and convert it into an SPI control word, and then output it to the digital control of each channel. Attenuators and RF switches complete the control of the entire beam.

A complete control word table covering the phase value and amplitude value of each RF signal channel is stored in the read-only memory 32, and the control word in the control word table is pre-written when the baseband processing board and the control unit calibrate the RF signal channel . Specifically, in the calibration process, a control word table written with all the corresponding points of amplitude and phase (that is, all possible control word combinations) is scanned, and the baseband processing board is used to automatically read the corresponding control words in the vector network analyzer. The amplitude and phase are determined by algorithm, and the points that meet the requirements are automatically selected and stored in the read-only register 32, that is, the pre-written control word. In this way, the corresponding control of the initial phase value and relative change of each channel is stored in the read-only memory, and when the radio frequency signal is controlled, the pre-written control word table can be read through the field programmable logic device 31. , saving the time and effort of manual calibration of traditional structures.

Further, when controlling the signals of each radio frequency channel, for different radio frequency channels, the initial amplitude can be adjusted to the same through the adjustment on the transceiver link, but the selection of the initial phase is different, thus greatly reducing the workload and resources of the previous calibration. occupancy. By means of automatic calibration, the corresponding control of the initial phase value and relative change of each channel is stored in the read-only memory 32 and read through the field programmable logic device 31, saving the time and effort of manual calibration of the traditional structure.

In summary, the amplitude and phase values of each RF channel can be adjusted through the baseband processing board and the control unit, so that not only can the direction of the beam be quickly and accurately controlled, but also the shape of the beam can be adjusted according to some calculations to achieve no Side lobe beam or double main lobe beam; due to the huge number of combinations of each amplitude and phase, the initial value is automatically calibrated by the field programmable logic device and the baseband processing board. When a radio frequency channel signal is used, the same table can be queried, but the initial phase selection is different, thereby greatly reducing the workload and resource occupancy of the previous calibration.

The integrated antenna array adopts a linear array structure, including at least two groups of bidirectional phase-shifted transceiver sub-arrays and at least one group of antenna sub-arrays; the antenna array includes multiple antenna units and multiple power dividers. As a preferred embodiment of the present invention, there are 2M groups of bidirectional phase-shifted transceiver sub-arrays, and M groups of antenna arrays. Each group of bi-directional phase-shifted transceiver sub-arrays includes N antenna units and N power dividers. The common end of the power divider of the power divider is connected to the antenna unit, and the separate end of the power divider is connected to two bidirectional phase-shifted transceiver units in two adjacent two-way phase-shifted transceiver sub-arrays. The antenna array of the embodiment shown in FIG. 1 includes two groups of bidirectional phase-shifted transceiver sub-arrays, and each group of bidirectional phase-shifted transceiver sub-arrays includes 8 bidirectional phase-shifted transceiver units. The in-phase power division module 6 uses 7 power dividers to divide one radio frequency signal into 8 radio frequency signals of the same amplitude and transmits them to the quadrature synthesis module of the 8 bidirectional phase-shifting transceiver units; a group of antenna sub-arrays includes the power divider 22 There are 8 in total, the common ends of the 8 power dividers 22 are respectively connected with the corresponding 8 antenna units 21, and the separate ends of the power dividers are connected with the two-way phase-shifting transceiver units in the two groups of different two-way phase-shifting transceiver sub-arrays at the same time. The distance between the two antenna units 21 is half the wavelength of the electromagnetic wave. Different from the traditional beamforming antenna array, the two sets of bidirectional phase-shifted transceiver sub-arrays used in the embodiment respectively perform beamforming on the input radio frequency signals. These unrelated beams are independent of each other and do not affect each other, so as to achieve the purpose of simultaneous communication and transmission with two users. Similarly, multiple groups of antenna arrays of bidirectional phase-shifted transceiver sub-arrays can also be designed according to the above method to realize simultaneous multi-user communication.

The antenna unit in the antenna array adopts a broadband dipole antenna, and the coverage can reach 120 degrees on the horizontal plane, which ensures that the electromagnetic wave signal within the working frequency band can be transmitted and received, and the production cost is low.

In conclusion, the working principle of the integrated antenna array disclosed in the embodiment is as follows:

When it is in the receiving state, the RF switch of each RF transceiver module is switched to the receiving state, and the RF signal is received and fed into the power divider through the antenna unit, and input into the RF transceiver modules of the two sub-arrays respectively. After passing the filter and RF amplifier, it enters the quadrature synthesis phase-shifting module to control the signal phase and amplitude of each channel, and then through the in-phase power division module, the same and equal-amplitude RF signals of N channels of a sub-array are synthesized into one RF signal The signal is sent to the base station, and N is 8 in the embodiment.

When it is in the transmitting state, the radio frequency switch of each radio frequency transceiver module is switched to the transmitting state, and the radio frequency signal is divided into N channels of equal and equal amplitude signals through the in-phase power division module, which are respectively input to the eight quadrature synthesis phase-shifting modules. The control of the quadrature synthesis phase-shifting module achieves the control of the phase and amplitude of each channel, and then the signals of each channel pass through the transmission chain of the radio frequency transceiver module 5, and pass through the band-pass filter 47, the radio frequency amplifier 46 and the power amplifier 48. The signal output from the power amplifier 48 is combined with the radio frequency signal corresponding to another sub-array through the power divider, and then radiated into the space through the antenna unit.

The following is a further description of this case in conjunction with an implementation case.

In this embodiment, the RF working center frequency of the antenna array is 3.5GHz, and the working bandwidth is 500MHz. The antenna array is a one-dimensional array with 8 elements in the horizontal direction distributed at equal half-wavelength spacing. 2*8, that is, it is divided into upper and lower sub-arrays, each sub-array includes 8 two-way phase-shifting transceiver units, the corresponding two-way phase-shifting transceiver units on the upper and lower layers are connected through a power divider, and the common end of the power divider is then connected. Access the antenna array. Therefore, each antenna array unit corresponds to the upper and lower two-way two-way phase-shifting transceiver units, and can transmit two communication signal streams at the same time; The maximum gain of the transmit chain is 16dB, and the maximum output power is 10dBm. The radiation beam of the antenna array has a 3dB beam width of 14° in the horizontal plane and a 3dB beam width of 78° in the vertical plane. The beam in the horizontal plane can be directed at any angle within the range of ±50°. For the single-channel bidirectional phase-shifting transceiver unit, the EVM (Error Vector Magnitude) test is carried out using the LTE signal of 20MHz TDD mode and different modulation modes. The results are shown in Table 1. At the same time, the adjacent channel power ratio ACPR (Adjacent Channel Power Ratio) It is -43.97dBc, which fully meets the communication requirements.

Table 1 EVM test results of LTE signals under different modulation modes

Modulation EVM value TDD-QPSK 0.321% TDD 16QAM 0.314% TDD 64QAM 0.316%

Figure 5 shows the test results of beam scanning in the horizontal plane of the present invention in the transmitting state, and a gain of 26 dB can be obtained at each angle. Figure 6 shows the beam scanning test results in the horizontal plane of the present invention in the receiving state. A gain of 21dB can be obtained at each angle; in order to ensure the accuracy and linearity of the beamforming angle, the two-way phase-shifting transceiver unit does not work at the maximum gain; although Figures 5 and 6 are 10° intervals Scanning is performed, but the actual beam can be pointed at any angle within ±50° with a phase accuracy of 0.31 degrees and an amplitude accuracy of 0.5dB.

It can be seen that in actual operation, the radio frequency signal is first decomposed into 16 signals of equal and equal amplitude, and then the amplitude and phase are adjusted by the quadrature synthesis phase-shifting module in the two-way phase-shifting transceiver. It can generate stable and accurate beamforming, and the beam pointing accuracy is 0.31 degrees and the coverage range is 110 degrees; the conversion time between different angles is completed within 3us through the quadrature synthesis phase-shifting module, which does not affect the normal communication symbols. Transmission, after testing, the optimized structure can achieve an EVM of 0.316% by transmitting 64QAM modulated LTE signals.

The above is only the preferred embodiment of the present invention, it should be pointed out that: for those skilled in the art, without departing from the principle of the present invention, several improvements and modifications can also be made, and these improvements and modifications are also It should be regarded as the protection scope of the present invention.

Claims (9)

1. A broadband hybrid beamforming integrated antenna array, characterized in that: comprising a bidirectional phase-shifted transceiver array, an antenna array and a control and calibration unit; wherein, The bidirectional phase-shifting transceiver array includes at least one in-phase power division module and a plurality of bidirectional phase-shifting transceiver units; the in-phase power division module includes a plurality of power dividers, which are used to divide a channel of radio frequency signals into multiple channels with equal and equal amplitude power. a radio frequency signal; the two-way phase-shifting transceiver unit includes a radio-frequency transceiver front-end module for amplifying the radio-frequency channel signal and a quadrature synthesis phase-shifting module for adjusting the phase and amplitude of the radio-frequency channel, and the radio-frequency channel includes receiving and transmitting signal channels; The antenna array includes a plurality of antenna units for radiating or receiving signals of each radio frequency channel; one end of the control and calibration unit is connected to each bidirectional phase-shifting transceiver unit, and the other end is connected to the baseband processing board, which is used for the entire broadband. The beamforming of the hybrid beamforming integrated antenna array is controlled and calibrated; The quadrature synthesis phase-shifting module includes a quadrature coupler, a first digitally controlled attenuator, a third radio frequency switch, a first transmission line transformer, a second numerically controlled attenuator, a fourth radio frequency switch, a second transmission line transformer and a power combiner; The input end of the quadrature coupler is connected to the in-phase power division module, and the 0-degree output end of the quadrature coupler is connected to the first input port of the power combiner through the first numerical control attenuator, the third radio frequency switch, and the first transmission line transformer in sequence; The 90-degree output end of the quadrature coupler is connected to the second input port of the power combiner through the second numerically controlled attenuator, the fourth radio frequency switch, and the second transmission line transformer in sequence, and the common port of the power combiner is connected to the radio frequency transceiver front-end module connected. 2. The integrated antenna array according to claim 1, wherein the orthogonal coupler, the numerical control attenuator, the radio frequency switch, the transmission line changer and the power combiner all adopt broadband devices, and the operating bandwidth range is 500MHz, Center frequency coverage from 2.5GHz to 3.5GHz. 3 . The integrated antenna array according to claim 1 , wherein the radio frequency transceiver front-end module comprises a receive amplification chain, a transmit amplification chain, a first radio frequency switch and a second radio frequency switch; wherein, The common terminal of the first radio frequency switch is connected to the quadrature synthesis phase-shifting module, and the transmitting port of the first radio frequency switch is connected to the transmitting port of the second radio frequency switch through the transmission amplification link; the common terminal of the second radio frequency switch is connected to the antenna array, and the second radio frequency switch is connected to the antenna array. The receiving port of the switch is connected to the receiving port of the first radio frequency switch through a receiving amplification link. 4. The integrated antenna array according to claim 3 is characterized in that: the transmitting and amplifying chain comprises a band-pass filter, a radio frequency amplifier and a power amplifier which are connected in sequence, and is used for correcting the slave positive when the radio frequency switch is turned on the transmitting port. The signals from the interleaved phase-shifting module are filtered and amplified, and then sent to the antenna array for radiation; the receiving and amplifying chain includes a low-noise amplifier, a band-pass filter and a radio frequency amplifier connected in sequence, which are used when the radio frequency switch is turned on the receiving port. The RF signal received from the antenna array is amplified and filtered, and then sent to the quadrature synthesis phase-shifting module. 5. The integrated antenna array according to claim 4, characterized in that: the working frequency band of the low-noise amplifier is 50MHz～4GHz, and the noise coefficient is 1.5dB; the working range of the radio frequency amplifier is 50MHz～6GHz; the working range of the power amplifier is 200MHz～6GHz; the performance requirements of the bandpass filter are that the insertion loss in the passband is less than 2dB, and the spurious suppression outside the band reaches 30dB. 6. The integrated antenna array according to claim 1, wherein the control and calibration unit comprises a control part, a control interface and a read-only memory; the read-only memory is connected and communicated with the control part, and the input end of the control part is connected to The baseband processing board, the output end is connected to each bidirectional phase-shifting transceiver unit through the control interface; the control part can choose programmable logic device or single-chip microcomputer. 7. The integrated antenna array according to claim 6, characterized in that: the read-only memory stores a control word table, and the control word table includes pre-written phase and amplitude values as control words; pre-written The phase and amplitude values are written by the baseband processing board during the initial phase calibration of each radio frequency channel, including the corresponding control of the initial phase value and relative change of each radio frequency channel. 8 . The integrated antenna array according to claim 7 , wherein when the baseband processing board performs initial phase calibration on each radio frequency channel, the initial amplitude is adjusted to be the same for different radio frequency channels, and only the initial phases are different. 9 . 9 . The integrated antenna array according to claim 1 , wherein the integrated antenna array adopts a linear array structure, comprising at least two groups of bidirectional phase-shifted transceiver sub-arrays and at least one group of antenna sub-arrays; the antennas The unit adopts a broadband dipole antenna with a bandwidth range of 500MHz.

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