阅读说明：本技术 毫米波实时成像人员安检系统的收发天线模块及系统 (Receiving and transmitting antenna module and system of millimeter wave real-time imaging personnel security check system ) 是由 费鹏 温鑫 李文扬 郭洧华 于 2020-12-09 设计创作，主要内容包括：本发明公开一种毫米波实时成像人员安检系统的收发天线模块及系统,包括：压控振荡器,用于产生微波频段调频连续波信号；倍频器,用于将所述微波频段调频连续波信号倍频后频率提升；毫米波信号与点频信号源,用于产生中频信号；混频器,用于对所述中频信号进行调制；第一放大器,用于对调制后的信号进行放大；发射开关阵列,用于接收放大后的信号,同时依次打开各发射通道,经多个发射天线发出毫米波电磁波；接收开关阵列,用于依次打开各接收通道,通过多个接收天线接收所述发射天线发出的经目标反射后的回波信号；第二放大器,用于对回波信号进行信号放大；第二混频器,用于对放大后的回波信号进行调制；本发明成像精度高和成像性能好。(The invention discloses a receiving and transmitting antenna module and a system of a millimeter wave real-time imaging personnel security check system, comprising: the voltage-controlled oscillator is used for generating a microwave frequency band frequency modulation continuous wave signal; the frequency multiplier is used for increasing the frequency of the microwave frequency band frequency modulation continuous wave signal after frequency multiplication; the millimeter wave signal and dot frequency signal source is used for generating an intermediate frequency signal; a mixer for modulating the intermediate frequency signal; a first amplifier for amplifying the modulated signal; the transmitting switch array is used for receiving the amplified signals, simultaneously opening each transmitting channel in sequence and transmitting millimeter wave electromagnetic waves through a plurality of transmitting antennas; the receiving switch array is used for sequentially opening each receiving channel and receiving echo signals sent by the transmitting antenna and reflected by the target through a plurality of receiving antennas; the second amplifier is used for amplifying the echo signal; the second mixer is used for modulating the amplified echo signal; the invention has high imaging precision and good imaging performance.)

1. The utility model provides a millimeter wave real-time imaging personnel security check system's receiving and dispatching antenna module which characterized in that includes:

the voltage-controlled oscillator is used for generating a microwave frequency band frequency modulation continuous wave signal;

the frequency multiplier is used for increasing the frequency of the microwave frequency band frequency modulation continuous wave signal after frequency multiplication to form a millimeter wave FMCW signal;

the millimeter wave signal and dot frequency signal source is used for generating an intermediate frequency signal;

a mixer for modulating the intermediate frequency signal;

a first amplifier for amplifying the modulated signal;

the transmitting switch array is used for receiving the amplified signals, simultaneously opening each transmitting channel in sequence and transmitting millimeter wave electromagnetic waves through a plurality of transmitting antennas;

the receiving switch array is used for sequentially opening each receiving channel and receiving echo signals sent by the transmitting antenna and reflected by the target through a plurality of receiving antennas;

the second amplifier is used for amplifying the echo signal;

the second mixer is used for modulating the amplified echo signal;

the third mixer is used for demodulating the modulated signal to obtain a baseband signal;

the analog-to-digital converter is used for receiving the baseband signal and performing analog-to-digital conversion;

and the FPGA is used for carrying out digital processing on the signals after the analog-digital conversion.

2. The transceiving antenna module of the millimeter wave real-time imaging personnel security check system of claim 1, wherein the plurality of transmitting antennas and the plurality of receiving antennas are arranged in a sparsely distributed structure.

3. The transceiving antenna module of the millimeter wave real-time imaging personnel security inspection system of claim 2, wherein the sparsely distributed structure comprises a plurality of minimum array modules, the plurality of minimum array modules are sequentially arranged according to a unit structure formed by a receiving antenna unit having a certain number of rows and a transmitting antenna unit having a certain number of columns, and an equivalent phase center formed by sequentially opening the transmitting switch array and the receiving switch array is formed between the receiving antenna unit and the transmitting antenna unit.

4. The transceiving antenna module of the millimeter wave real-time imaging personnel security check system of claim 3, wherein: the number of the transmitting antenna units is equal to or different from the number of the receiving antenna units.

5. The utility model provides a millimeter wave real-time imaging personnel safety inspection system's receiving and dispatching antenna system which characterized in that includes: a plurality of arrays, the unit structure that a plurality of arrays formed according to the receiving antenna unit that has certain row number and the transmitting antenna unit that has certain column number arranges in proper order, wherein, array module includes:

the voltage-controlled oscillator is used for generating a microwave frequency band frequency modulation continuous wave signal;

the frequency multiplier is used for increasing the frequency of the microwave frequency band frequency modulation continuous wave signal after frequency multiplication to form a millimeter wave FMCW signal;

the millimeter wave signal and dot frequency signal source is used for generating an intermediate frequency signal;

a mixer for modulating the intermediate frequency signal;

a first amplifier for amplifying the modulated signal;

the array composed of the transceiving antenna units is used for transmitting and receiving millimeter wave electromagnetic waves in a specified power, bandwidth and polarization mode;

the second amplifier is used for amplifying the echo signal of the millimeter wave electromagnetic wave;

the second mixer is used for modulating the amplified echo signal;

the third mixer is used for demodulating the modulated signal to obtain a baseband signal;

the analog-to-digital converter is used for receiving the baseband signal and performing analog-to-digital conversion;

and the FPGA is used for carrying out digital processing on the signals after the analog-digital conversion.

6. The transceiving antenna system of the millimeter wave real-time imaging personnel security check system of claim 5, wherein a receiving antenna circuit board or a transmitting antenna circuit board is integrated on the array consisting of the transceiving antenna units.

7. The transceiving antenna system of the millimeter wave real-time imaging personnel security check system of claim 6, wherein: and the output port of the receiving antenna circuit board or the transmitting antenna circuit board is connected with the antenna circuit board control switch.

8. The transceiving antenna system of the millimeter wave real-time imaging personnel security check system of claim 6, wherein the transmitting antenna circuit board or the receiving antenna circuit board adopts a trapezoidal outer profile.

Technical Field

The invention belongs to the technical field of communication, and particularly relates to a receiving and transmitting antenna module and a system of a millimeter wave real-time imaging personnel security check system.

Background

As the global process advances, terrorist activities evolve from local problems to global crisis. Particularly, after the 911 event, the security inspection problem of personnel becomes the focus of attention of all countries in the world, and the security inspection technology of various new systems is emerging. In the human body security inspection technology based on imaging detection, millimeter wave human body security inspection has attracted people's wide interest. Compared with X-ray, the millimeter wave does not cause ionization effect, is safe and harmless to human body under certain power, and is more easily accepted by the public; compared with the infrared and visible light frequency bands, the microwave millimeter waves can penetrate through the shielding of clothes to directly image hidden dangerous goods; compared with low-frequency microwaves, millimeter wave imaging has higher imaging resolution and smaller device size, is very suitable for the characteristics of concealment, diversification and miniaturization of the existing explosion devices and prohibited articles, and is an ideal frequency band for human body security inspection. In the existing millimeter wave security inspection technology, passive millimeter wave security inspection imaging inverts the radiation bright temperature of a target, and the passive millimeter wave security inspection imaging is essentially a millimeter wave radiometer and has the advantage of good real-time performance, but the technology has poor imaging quality and low precision. In contrast, the active imaging technology has a complete signal transmitting and receiving system, can provide higher signal-to-noise ratio and target contrast, and has higher imaging quality and precision than passive imaging. However, in the existing active millimeter wave human body security inspection embodiments, such as the Provision series cylindrical scanning millimeter wave security inspection instrument of L3, the same-square MW1000 series planar scanning millimeter wave security inspection instrument, and the like, the synthetic aperture radar imaging technology combining electrical scanning and mechanical scanning is adopted, the data acquisition time is in the second level, and the person to be inspected must scan in accordance with the designated station and posture. A QPS100 flat millimeter wave security inspection instrument of Rohde & Schwarz company in Germany adopts an electric scanning human body imaging system based on a digital beam forming technology, can realize quasi-real-time data acquisition of detected personnel, but cannot realize real-time imaging at present due to huge data volume. The active millimeter wave security check efficiency is low, and the requirement of real-time passing under a large passenger flow scene cannot be met. In recent years, with the continuous progress of radar technology and computer technology, the fast processing capability of radar signals has been greatly improved. Two-dimensional and even three-dimensional radar target real-time imaging becomes possible. At a data acquisition end, the working mode of MIMO (Multi Input Multi output) of radar Multi-antenna simultaneous transmission and Multi-antenna simultaneous reception can obtain equivalent observation channels far more than the number of actual antennas at relatively low cost, and the system performance of radar in radar imaging is superior to that of radar in a traditional system. Therefore, the millimeter wave real-time three-dimensional imaging technology based on the MIMO technology is called as an important development direction of next-generation human body security check, and the prior art needs to wait for the transceiver antenna module of the millimeter wave real-time imaging personnel security check system to achieve the purposes of high imaging precision and good imaging performance.

Disclosure of Invention

The invention aims to provide a receiving and transmitting antenna module and a receiving and transmitting antenna system of a millimeter wave real-time imaging personnel security check system, and solves the problems of high imaging precision and good imaging performance of the millimeter wave imaging personnel security check system.

In view of this, the present invention provides a transceiving antenna module of a millimeter wave real-time imaging personnel security check system, which is characterized by comprising:

the voltage-controlled oscillator is used for generating a microwave frequency band frequency modulation continuous wave signal;

the frequency multiplier is used for increasing the frequency of the microwave frequency band frequency modulation continuous wave signal after frequency multiplication to form a millimeter wave FMCW signal;

the millimeter wave signal and dot frequency signal source is used for generating an intermediate frequency signal;

a mixer for modulating the intermediate frequency signal;

a first amplifier for amplifying the modulated signal;

the transmitting switch array is used for receiving the amplified signals, simultaneously opening each transmitting channel in sequence and transmitting millimeter wave electromagnetic waves through a plurality of transmitting antennas;

the receiving switch array is used for sequentially opening each receiving channel and receiving echo signals sent by the transmitting antenna and reflected by the target through a plurality of receiving antennas;

the second amplifier is used for amplifying the echo signal;

the second mixer is used for modulating the amplified echo signal;

the third mixer is used for demodulating the modulated signal to obtain a baseband signal;

the analog-to-digital converter is used for receiving the baseband signal and performing analog-to-digital conversion;

and the FPGA is used for carrying out digital processing on the signals after the analog-digital conversion.

Further, the plurality of transmitting antennas and the plurality of receiving antennas are arranged in a sparsely distributed structure.

Furthermore, the sparsely distributed structure includes a plurality of minimum array modules, the minimum array modules are sequentially arranged according to a unit structure formed by a receiving antenna unit having a certain number of rows and a transmitting antenna unit having a certain number of columns, and an equivalent phase center formed by sequentially opening the transmitting switch array and the receiving switch array is arranged between the receiving antenna unit and the transmitting antenna unit.

Further, the number of the transmitting antenna elements is equal to or different from the number of the receiving antenna elements.

Another object of the present invention is to provide a transmitting/receiving antenna system of a millimeter wave real-time imaging personnel security check system, comprising: a plurality of arrays, the unit structure that a plurality of arrays formed according to the receiving antenna unit that has certain row number and the transmitting antenna unit that has certain column number arranges in proper order, wherein, array module includes:

the voltage-controlled oscillator is used for generating a microwave frequency band frequency modulation continuous wave signal;

the frequency multiplier is used for increasing the frequency of the microwave frequency band frequency modulation continuous wave signal after frequency multiplication to form a millimeter wave FMCW signal;

the millimeter wave signal and dot frequency signal source is used for generating an intermediate frequency signal;

a mixer for modulating the intermediate frequency signal;

a first amplifier for amplifying the modulated signal;

the array composed of the transceiving antenna units is used for transmitting and receiving millimeter wave electromagnetic waves in a specified power, bandwidth and polarization mode;

the second amplifier is used for amplifying the echo signal of the millimeter wave electromagnetic wave;

the second mixer is used for modulating the amplified echo signal;

the third mixer is used for demodulating the modulated signal to obtain a baseband signal;

the analog-to-digital converter is used for receiving the baseband signal and performing analog-to-digital conversion;

and the FPGA is used for carrying out digital processing on the signals after the analog-digital conversion.

Furthermore, a receiving antenna circuit board or a transmitting antenna circuit board is integrated on the array formed by the transmitting and receiving antenna units.

Further, the output port of the receiving antenna circuit board or the transmitting antenna circuit board is connected with an antenna circuit board control switch.

Further, the transmitting antenna circuit board or the receiving antenna circuit board adopts a trapezoidal outer contour.

The invention achieves the following significant beneficial effects:

simple structure includes: the voltage-controlled oscillator is used for generating a microwave frequency band frequency modulation continuous wave signal; the frequency multiplier is used for increasing the frequency of the microwave frequency band frequency modulation continuous wave signal after frequency multiplication to form a millimeter wave FMCW signal; the millimeter wave signal and dot frequency signal source is used for generating an intermediate frequency signal; a mixer for modulating the intermediate frequency signal; a first amplifier for amplifying the modulated signal; the transmitting switch array is used for receiving the amplified signals, simultaneously opening each transmitting channel in sequence and transmitting millimeter wave electromagnetic waves through a plurality of transmitting antennas; the receiving switch array is used for sequentially opening each receiving channel and receiving echo signals sent by the transmitting antenna and reflected by the target through a plurality of receiving antennas; the second amplifier is used for amplifying the echo signal; the second mixer is used for modulating the amplified echo signal; the third mixer is used for demodulating the modulated signal to obtain a baseband signal; the analog-to-digital converter is used for receiving the baseband signal and performing analog-to-digital conversion; and the FPGA is used for carrying out digital processing on the signals after the analog-digital conversion. The imaging precision is high, the imaging performance is good, and the millimeter wave real-time imaging personnel security inspection system is suitable for.

Drawings

FIG. 1 is a schematic structural diagram of a transmitting-receiving antenna module of the millimeter wave real-time imaging personnel security inspection system of the present invention;

FIG. 2 is a schematic diagram of the distribution of the transceiver units according to the present invention;

fig. 3 is a schematic diagram of a layered structure of the millimeter wave transceiver antenna module according to the present invention;

FIG. 4 is a schematic diagram of an expanded embodiment among the modules of the present invention;

FIG. 5 is a schematic diagram of another expanded embodiment among the modules of the present invention;

FIG. 6 is a schematic diagram of an embodiment of a circularly polarized array with the antenna radiation direction on the broad side of the antenna circuit board;

FIG. 7 is a schematic view of an embodiment of a linearly polarized array with antenna radiation directions on the narrow sides of the antenna circuit board;

fig. 8 is a schematic structural diagram of a transmitting-receiving antenna array of the millimeter wave real-time imaging personnel security inspection system of the present invention.

Schematic of the reference numerals

101 a voltage controlled oscillator; 102 a frequency multiplier; 103 a mixer; 104 an amplifier; 105 an array of transmit switches;

106 a transmit antenna; 107 target; 108 receiving antenna, 109 low noise amplifier; 110 receive a switch array;

111 a mixer; 113 an analog-to-digital converter; 114 a Field Programmable Gate Array (FPGA); 105 electric frequency signal source

201 a minimum array module; 202 a receiving antenna unit; 203 a transmit antenna unit; 204 equivalent phase centers;

205 may share transmit antenna elements; 206 may share receive antenna elements; 207 adjacent to the smallest array module;

208 adjacent to the smallest array module; 209 millimeter wave transceiver antenna module

301 an array of transceiving antenna elements; a signal distribution layer of the 302 millimeter wave transceiver antenna module; 303 transceiver

401 millimeter wave transceiver antenna module; 402 millimeter wave transceiver antenna module; 403 millimeter wave transceiver antenna module;

404 millimeter wave transceiver antenna module; 405 signal processing layer

501 receive (or transmit) antenna circuit board; 502 an antenna element; 503 a primary switch; 504 a secondary switch;

505 the antenna circuit board controls the switch module; 506 antenna circuit board control switch input (output) port

601 a transmit antenna circuit board; 602 a receive antenna unit; 603 receiving an antenna circuit board; 604 transmit antenna unit

701 a transmitting antenna circuit board; 702 a receive antenna unit; 703 a receiving antenna circuit board; 704 a transmit antenna unit;

705 fixing the structure; 801 receiving antenna circuit board, 802 transmitting antenna circuit board;

803 receive the antenna circuit board control switch module; 804 the transmitting antenna circuit board controls the switch module; 805 transceiver

Detailed Description

The advantages and features of the present invention will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings and detailed description of specific embodiments of the invention. It is to be noted that the drawings are in a very simplified form and are not to scale, which is intended merely for convenience and clarity in describing embodiments of the invention.

It should be noted that, for clarity of description of the present invention, various embodiments are specifically described to further illustrate different implementations of the present invention, wherein the embodiments are illustrative and not exhaustive. In addition, for simplicity of description, the contents mentioned in the previous embodiments are often omitted in the following embodiments, and therefore, the contents not mentioned in the following embodiments may be referred to the previous embodiments accordingly.

While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood that the inventors do not intend to limit the invention to the particular embodiments described, but intend to protect all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the claims. The same meta-module part number may be used throughout the drawings to represent the same or similar parts.

Referring to fig. 1 to 8, the present invention provides a transceiver antenna module of a millimeter wave real-time imaging personnel security inspection system, including:

the voltage-controlled oscillator is used for generating a microwave frequency band frequency modulation continuous wave signal;

the frequency multiplier is used for increasing the frequency of the microwave frequency band frequency modulation continuous wave signal after frequency multiplication to form a millimeter wave FMCW signal;

the millimeter wave signal and dot frequency signal source is used for generating an intermediate frequency signal;

a mixer for modulating the intermediate frequency signal;

a first amplifier for amplifying the modulated signal;

the transmitting switch array is used for receiving the amplified signals, simultaneously opening each transmitting channel in sequence and transmitting millimeter wave electromagnetic waves through a plurality of transmitting antennas;

the receiving switch array is used for sequentially opening each receiving channel and receiving echo signals sent by the transmitting antenna and reflected by the target through a plurality of receiving antennas;

the second amplifier is used for amplifying the echo signal;

the second mixer is used for modulating the amplified echo signal;

the third mixer is used for demodulating the modulated signal to obtain a baseband signal;

the analog-to-digital converter is used for receiving the baseband signal and performing analog-to-digital conversion;

and the FPGA is used for carrying out digital processing on the signals after the analog-digital conversion.

In one embodiment, the plurality of transmitting antennas and the plurality of receiving antennas are arranged in a sparsely distributed structure.

In one embodiment, the sparsely distributed structure includes a plurality of minimum array modules, the minimum array modules are sequentially arranged according to a unit structure formed by a receiving antenna unit having a certain number of rows and a transmitting antenna unit having a certain number of columns, and an equivalent phase center formed by sequentially turning on the transmitting switch array and the receiving switch array is located between the receiving antenna unit and the transmitting antenna unit.

In one embodiment, the number of transmit antenna elements is equal to or different from the number of receive antenna elements.

Another object of the present invention is to provide a receiving and transmitting antenna system of a millimeter wave real-time imaging personnel security check system, comprising: a plurality of arrays, the unit structure that a plurality of arrays formed according to the receiving antenna unit that has certain row number and the transmitting antenna unit that has certain column number arranges in proper order, wherein, array module includes:

the voltage-controlled oscillator is used for generating a microwave frequency band frequency modulation continuous wave signal;

the frequency multiplier is used for increasing the frequency of the microwave frequency band frequency modulation continuous wave signal after frequency multiplication to form a millimeter wave FMCW signal;

the millimeter wave signal and dot frequency signal source is used for generating an intermediate frequency signal;

a mixer for modulating the intermediate frequency signal;

a first amplifier for amplifying the modulated signal;

the array composed of the transceiving antenna units is used for transmitting and receiving millimeter wave electromagnetic waves in a specified power, bandwidth and polarization mode;

the second amplifier is used for amplifying the echo signal of the millimeter wave electromagnetic wave;

the second mixer is used for modulating the amplified echo signal;

the third mixer is used for demodulating the modulated signal to obtain a baseband signal;

the analog-to-digital converter is used for receiving the baseband signal and performing analog-to-digital conversion;

and the FPGA is used for carrying out digital processing on the signals after the analog-digital conversion.

In one embodiment, a receive antenna circuit board or a transmit antenna circuit board is integrated on the array of transceiver antenna elements.

In one embodiment, an output port of the receiving antenna circuit board or the transmitting antenna circuit board is connected with an antenna circuit board control switch.

In one embodiment, the transmit antenna circuit board or the receive antenna circuit board adopts a trapezoidal outer profile.

As a specific embodiment, the internal components of the transceiver antenna array module of the present invention are shown in fig. 1, a voltage-controlled oscillator 101 generates a microwave frequency-modulated continuous wave (FMCW) signal, which is frequency-multiplied by a frequency multiplier 102 and then frequency-boosted to become a millimeter-wave FMCW signal. The millimeter wave signal and the intermediate frequency signal generated by the dot frequency signal source 115 are modulated by the mixer 103, amplified by the amplifier 104, and then enter the 105-channel switch array. 105, the channels are opened in turn, the signal is transmitted by the transmitting antenna 106, reflected by the target 107, received back by the receiving antenna 108, and amplified by the low noise amplifier 109. The receiving channel switch array 110 is sequentially turned on, the echo signals received by each channel enter the mixers 111 and 112 to be demodulated to obtain baseband signals, and finally the baseband signals are sent to the analog-to-digital converter 113 and then enter a digital domain to enter a digital signal processing flow.

As a specific example, to achieve real-time imaging, the present invention employs an all-electric scanning embodiment to increase the rate of data acquisition. According to the characteristics of the real-time imaging personnel security check system, the transmitting and receiving antennas are sparsely distributed. Fig. 2 shows the distribution of the transceiver units. 201 is the smallest array module. Reference numeral 202 denotes a receiving antenna unit, which is shown as an upper row and a lower row, each row has 10 antenna elements, and the antenna element pitch is generally selected from 0.5 λ to 3 λ, where λ is the wavelength of the operating frequency. 203 transmitting antenna units, wherein the figure has a left and a right 2 columns, each column is 10, and the antenna spacing is generally selected to be 0.5 lambda-3 lambda. 204 is the equivalent phase center when 202 receiving antenna units and 204 transmitting units are opened, and in 201, 20 transmitting and 20 receiving antenna units are opened in sequence, and paired in pairs to form 20 × 20 equivalent phase centers. It should be noted that the number of receiving and transmitting units in fig. 3 is only illustrative, the number of receiving antenna units in each column may be any number N, the number of transmitting antenna units in each row may be any number M, and M may be equal to or different from N. In practical engineering, the larger the values of N and M, the larger the size of the array and the higher the sparsity, the better the economy, but the increase of N and M can significantly increase the deterioration degree of the point spread function of the system, thereby affecting the imaging quality. 207 is the smallest array module adjacent to 201. They are adjacent to each other, and in order to further reduce the cost, a preferred embodiment is that M units of the linear array of transmitting antenna units 205 can be shared by the smallest array modules of 201 and 207. Similarly, the N number of units in the linear array of receiving antenna units 206 can be shared by the smallest array modules 201 and 208. In fig. 2, 4 minimum array modules constitute a larger millimeter wave transceiver antenna module 209. It is noted that it is preferable to have 209 a minimum array of 4, and in practice 209 may be made up of other minimum arrays, such as 9 or 16, taking into account the complexity and cost-effectiveness of the system. For convenience of description, the following figures and description are provided for the case where 1 millimeter wave transceiver antenna module is composed of 4 minimum arrays.

As a specific embodiment, fig. 3 is a schematic diagram of a layered structure of a millimeter wave transceiver antenna module. 301 is an array of transceiving antenna elements, corresponding to 106 and 108 in fig. 1. The function is to transmit and receive millimeter wave electromagnetic waves in a specified power, bandwidth, polarization. 302 is the signal distribution layer of the millimeter wave transceiver antenna module, corresponding to 105 and 110 in fig. 1. The function is to control the opening and closing of the receiving and transmitting units, realize the switching of the receiving and transmitting channels, and complete the signal acquisition in all equivalent phase centers in all the receiving and transmitting channels in 209. Reference numeral 303 denotes a transceiver, corresponding to reference numerals 101 to 104 and 111 to 115 in fig. 1, which functions to generate, amplify, mix, demodulate and analog-to-digital convert the echo signals.

As a specific example, fig. 4 is an extended example between modules. 401-404 are millimeter wave transceiver antenna modules. Through the 405 signal processing layers behind, the data obtained by the millimeter wave transceiving antenna modules can be fused and spliced, and the imaging effect of a larger caliber is achieved. It is to be noted that the extension number of the millimeter wave transceiving antenna is not limited to 4 in the drawing, and they may be arranged adjacent to each other to constitute a larger array. The number of final modules is usually determined by conditions such as floor space size, budget, computing power, etc.

As a specific embodiment, each millimeter wave transceiver antenna module in this embodiment shares one transceiver, so that only 1 receiving channel and 1 transmitting channel can be allowed to be opened at the same time. When the number of the receiving and transmitting antennas of the minimum array module is large (for example, more than 20 antennas), the switching control of each channel can be realized only by a multi-stage switch. The signal distribution function of 302 in fig. 3 is partially integrated into the feed network of the antenna of 301, which can effectively improve the integration level of the system and reduce the insertion loss of the module. In a preferred embodiment, as shown in fig. 5, 501 is a receiving (or transmitting) antenna circuit board, on which a primary switch 503 and a secondary switch 504 are integrated in addition to an antenna unit 502, and if necessary, a three-stage and a four-stage … switch can be further integrated. The opening and closing of each antenna of the antenna circuit board can be realized through each stage of switch and the control signal corresponding to the switch. The output port of each receiving (or transmitting) antenna circuit board is connected with 505 an antenna circuit board control switch, and the switch controls the on and off of each antenna circuit board, and 505, 504 and 503 work cooperatively, so that only 1 antenna is switched on at the same time and is in a working state. The antenna is connected to a receiver or transmitter via a port 506 at 505.

As specific examples, the form of the antenna element may be selected from a microstrip antenna, a horn antenna, a Vivaldi antenna, a dipole antenna, a helical antenna, and the like. The polarization form of the antenna element may be linear polarization, circular polarization or elliptical polarization. As shown in fig. 6, a transmitting antenna circuit board 601 and a receiving antenna circuit board 603 have trapezoidal outer contours to avoid interference with each other. Since the circular polarization changes after the target reflects once, the receiving antenna unit 602 and the transmitting antenna unit 604 have opposite linear polarization directions to ensure polarization matching. Preferably, a microstrip antenna or a horn antenna can be selected as an antenna array unit under the array layout. A linear polarization array with antenna radiation direction on the narrow side of the antenna circuit board as shown in fig. 7, the transmitting antenna circuit board 701 and the receiving antenna circuit board 703 are vertically spliced with each other and can be reinforced by fixing structures 705 and 706. The receive antenna elements shown at 702 have the same linear polarization as the transmit antenna elements shown at 704 to ensure polarization matching. Preferably, dipole antennas or Vivaldi antennas can be selected as array elements in such an array layout.

As a specific embodiment, the antenna circuit boards 601, 603, 701, and 703 may be integrated with level 1 and level 2 switches, thereby improving the system integration. Fig. 8 is a preferred integrated embodiment of a transceiver antenna module. As shown in the figure, the receiving antenna circuit board 801 and the transmitting antenna circuit board 802 form the back of the array, and a receiving antenna circuit board control switch module 803 and a transmitting antenna circuit board control switch module 804 are fixed, and are respectively connected with all the receiving antenna circuit board and transmitting antenna circuit board ports. 805 is a transceiver, which is connected to ports of 803 and 804, so as to realize the transceiving of signals.

The invention achieves the following significant beneficial effects:

simple structure includes: the voltage-controlled oscillator is used for generating a microwave frequency band frequency modulation continuous wave signal; the frequency multiplier is used for increasing the frequency of the microwave frequency band frequency modulation continuous wave signal after frequency multiplication to form a millimeter wave FMCW signal; the millimeter wave signal and dot frequency signal source is used for generating an intermediate frequency signal; a mixer for modulating the intermediate frequency signal; a first amplifier for amplifying the modulated signal; the transmitting switch array is used for receiving the amplified signals, simultaneously opening each transmitting channel in sequence and transmitting millimeter wave electromagnetic waves through a plurality of transmitting antennas; the receiving switch array is used for sequentially opening each receiving channel and receiving echo signals sent by the transmitting antenna and reflected by the target through a plurality of receiving antennas; the second amplifier is used for amplifying the echo signal; the second mixer is used for modulating the amplified echo signal; the third mixer is used for demodulating the modulated signal to obtain a baseband signal; the analog-to-digital converter is used for receiving the baseband signal and performing analog-to-digital conversion; and the FPGA is used for carrying out digital processing on the signals after the analog-digital conversion. The imaging precision is high, the imaging performance is good, and the millimeter wave real-time imaging personnel security inspection system is suitable for.

Any other suitable modifications are possible according to the technical embodiments and concepts of the present invention. All such alternatives, modifications and improvements as would be obvious to one skilled in the art are intended to be included within the scope of the invention as defined by the appended claims.