A method for constructing time-division MIMO antennas with overlapping subarrays

Abstract

This invention discloses a method for constructing a time-division MIMO antenna with overlapping subarrays, relating to the technical field of information sensing and recognition technology. The invention involves a receiving antenna array (N×M), a transmitting antenna array (q)×(p(M)+L), a time-division control unit, a MIMO array acquisition unit, etc., equivalent to simulating a receiving array size of (q×N)×(p×M). A practical example of this method shows that an active transmitting array in the elevation dimension is divided into two elevation subarrays through time-division control. Each elevation subarray is equivalent to one transmitting element in a time-division MIMO, achieving a subarray element reuse rate of 66.7%. This solves the problem of short detection range in time-division MIMO radar, enabling time-division MIMO technology and active phased array technology to complement each other in engineering, achieving flexibility and practicality in MIMO implementation.

Description

Technical Field

[0001] This invention relates to the technical field of information perception and recognition technology, and belongs to a method for constructing a time-division MIMO transmit antenna with overlapping subarrays related to intelligence perception and detection. It is applicable to the radio frequency antenna application of reconnaissance and detection radar systems. Background Technology

[0002] Currently, traditional phased array radar antennas have solid apertures, and due to antenna limitations, their radar resolution is comparable to that of solid aperture antennas. MIMO (Multiplexing Induction Mode) antenna arrangements utilize time-division multiplexing to achieve spatial synthesis of the receiving antennas. However, due to limitations in the transmitting antenna array, the power amplifier output power required for a single transmitting antenna is significantly higher than that of a traditional phased array antenna, placing certain requirements on heat dissipation, power supply, size, and weight. Employing overlapping subarrays of transmitting antennas combines the advantages of the rational power distribution of phased array radar transmitting antennas with the ability to achieve large-scale receiving arrays, thus improving angular resolution. Summary of the Invention

[0003] This invention discloses a method for constructing a time-division MIMO antenna with overlapping subarrays. Unlike traditional radar phased array antenna arrays, it adopts a time-division multiplexing-spatial synthesis MIMO method to combine the multiplexing high power of overlapping subarrays with time-division array reception synthesis.

[0004] To achieve the above-mentioned technical effects, the technical solution adopted by the present invention is as follows: A method for constructing a time-division MIMO antenna with overlapping subarrays includes the following steps: Step 1: Construct a receiving antenna array. The receiving antenna array adopts a phased array antenna form, which has N×M receiving antenna elements, where N is the number of horizontal array elements and M is the number of vertical array elements. The selection of N and M meets the requirements of angular coverage and angular resolution. The horizontal spacing between adjacent receiving antenna elements is X, which meets the azimuth scanning range and grid lobe requirements of the phased array antenna. The vertical spacing between adjacent receiving antenna elements is Y, which meets the elevation scanning range and grid lobe requirements of the phased array antenna. The equivalent gain of the receiving antenna array is Gr, the azimuth resolution is θa, and the elevation resolution is θe. Step 2: Construct the transmitting antenna array, which adopts a MIMO phased array antenna; the transverse array of the transmitting antenna array is implemented using the MIMO method, the total transverse width of the transmitting antenna element is (q-1)×(N×X), the element spacing is NX, q is the number of columns of the transmitting antenna array; the equivalent antenna gain of the transverse array of the transmitting antenna array is Gt. The longitudinal array of the transmitting antenna array is implemented by subarray overlap and phased array, where the number of overlapping subarrays is L; the number of elements in the longitudinal array is (p-1)M+L, and the longitudinal spacing between the transmitting antenna elements is Y, where p is the equivalent longitudinal number of elements in the transmitting antenna array; Step 3: Construct a time-division control unit. The time-division control unit forms a MIMO antenna through time-division multiplexing and spatial synthesis. The number of synthesized receiving antenna elements is (q×(N))×(p×(M)); the equivalent antenna azimuth resolution is θa / q, and the equivalent antenna elevation resolution is θe / p. Step 4: Construct a MIMO array acquisition unit, which is designed for the antenna element arrangement of the receiving antenna array and linked with the radio frequency unit, frequency conversion unit and acquisition unit according to the actual usage to realize the reception of radar signals; and realize the acquisition of receiving antenna array data through the time division control unit.

[0005] Furthermore, in step 3, time division multiplexing specifically refers to: according to the time distribution, controlling the transmitting antenna array to switch elevation from (1, L), (M+1, M+L), ..., ((p-1)M+1, (p-1)M+L), and simultaneously switching azimuth according to 1 to q, so as to realize MIMO synthesis control of the receiving antenna array.

[0006] The advantages of this invention compared to the prior art are: By employing a spatial synthetic transmitter with overlapping subarrays, the feasibility of high transmit power for MIMO radar is improved. The use of time-division multiplexing MIMO radar system improves the angular resolution of the corresponding space; It balances the feasibility of transmitting power with spatial resolution. Attached Figure Description

[0007] Figure 1 This is a schematic diagram of the components of the present invention.

[0008] Figure 2 This is a schematic diagram of the actual MIMO transmit and receive antennas and the synthesized antenna of this invention. Detailed Implementation

[0009] The present invention will be further explained and described below with reference to the accompanying drawings and specific embodiments.

[0010] A method for constructing a time-division MIMO transmit antenna with overlapping subarrays is presented. A practical example of this method divides an active transmit array into two elevation subarrays via time-division control. Each elevation subarray is equivalent to one transmit element in a time-division MIMO system. The reuse rate of elements between subarrays reaches 66.7%, solving the problem of short detection range in time-division MIMO radar. This method allows time-division MIMO technology and active phased array technology to complement each other in engineering, achieving a close integration and greater flexibility and practicality in MIMO implementation. The method includes the following steps: Practical example of a receiving antenna array: The antenna element size is 32×4 elements. The horizontal element N is chosen to be 32, primarily based on ensuring a 90° azimuth scanning range and approximately 3.5° azimuth resolution. The azimuth element spacing is 0.55λ. The vertical element M is chosen to be 4, and MIMO is proposed to improve elevation resolution. Considering the 30° scanning range requirement, the vertical element spacing is 0.7λ, resulting in an elevation resolution of 30°. The antenna's equivalent gain is approximately 23dB.

[0011] Practical example of transmitting antenna array: The horizontal antenna array adopts a single antenna form to meet the requirement of horizontal coverage of 90° azimuth; the total number of vertical elements is 16, and the equivalent antenna gain is 18dB.

[0012] The transmitting longitudinal antenna array adopts a subarray overlapping method and is implemented using a general phased array method. There are 12 overlapping subarrays, and the practical example of the transmit power of a single element is 30W (typically 10W to 50W). The spacing between the elements is the same as the spacing between the longitudinal elements of the receiving antenna array (0.7λ). The total number of elements in the longitudinal antenna array is (2-1)4+12=16.

[0013] The total transmit power is 360W. The elevation of the transmitting antenna array can be shaped by amplitude and phase weighting.

[0014] Practical example of a time-division control unit: It primarily relies on two time-division multiplexing operations plus elevation spatial synthesis to form a MIMO antenna system. The number of synthesized receiving antenna elements is 32×8. The equivalent antenna azimuth resolution is 3.5°, and the equivalent antenna elevation resolution is 15°. The time-division multiplexing method controls the elevation switching of the transmitting antenna using two arrays (1, 12) and (5, 16) based on the time distribution. This achieves MIMO synthesis control of the receiving antenna array.

[0015] Practical example of a MIMO array acquisition unit: For a 32×4 receiving antenna array, it can be linked with the RF unit, frequency conversion unit, and acquisition unit according to the receiving antenna and actual usage to achieve acquisition of 128 channels. Combined with a time-division control unit that operates every 200ms, it takes a total of 400ms to acquire data from the entire array of 256 elements across 32×8 channels.

[0016] Completing the above steps completes the construction of the time-division MIMO transmit antenna with overlapping subarrays.

Claims

1. A method for constructing a time-division MIMO antenna with overlapping subarrays, characterized in that, Specifically, the following steps are included: Step 1: Construct a receiving antenna array. The receiving antenna array adopts a phased array antenna form, which has N×M receiving antenna elements, where N is the number of horizontal array elements and M is the number of vertical array elements. The selection of N and M meets the requirements of angular coverage and angular resolution. The horizontal spacing between adjacent receiving antenna elements is X, which meets the azimuth scanning range and grid lobe requirements of the phased array antenna. The vertical spacing between adjacent receiving antenna elements is Y, which meets the elevation scanning range and grid lobe requirements of the phased array antenna. The equivalent gain of the receiving antenna array is Gr, the azimuth resolution is θa, and the elevation resolution is θe. Step 2: Construct the transmitting antenna array, which adopts a MIMO phased array antenna; the transverse array of the transmitting antenna array is implemented using the MIMO method, the total transverse width of the transmitting antenna element is (q-1)×(N×X), the element spacing is NX, q is the number of columns of the transmitting antenna array; the equivalent antenna gain of the transverse array of the transmitting antenna array is Gt. The longitudinal array of the transmitting antenna array is implemented by subarray overlap and phased array, where the number of overlapping subarrays is L; the number of elements in the longitudinal array is (p-1)M+L, and the longitudinal spacing between the transmitting antenna elements is Y, where p is the equivalent longitudinal number of elements in the transmitting antenna array; Step 3: Construct a time-division control unit. The time-division control unit forms a MIMO antenna through time-division multiplexing and spatial synthesis. The number of synthesized receiving antenna elements is (q×(N))×(p×(M)); the equivalent antenna azimuth resolution is θa / q, and the equivalent antenna elevation resolution is θe / p. Step 4: Construct a MIMO array acquisition unit, which is designed for the antenna element arrangement of the receiving antenna array and linked with the radio frequency unit, frequency conversion unit and acquisition unit according to the actual usage to realize the reception of radar signals; and realize the data acquisition of the receiving antenna array through the time division control unit.

2. The method for constructing a time-division MIMO antenna with overlapping subarrays according to claim 1, characterized in that, In step 3, time division multiplexing specifically refers to: according to the time distribution, controlling the transmitting antenna array to switch elevation from (1, L), (M+1, M+L), ..., ((p-1)M+1, (p-1)M+L), and simultaneously switching azimuth according to 1 to q, so as to realize MIMO synthesis control of the receiving antenna array.

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