CN102938504A - Single-board microstrip slot phased-array antenna with simple beam control system - Google Patents

Abstract

A single-board microstrip slot phased array antenna based on single-board system integration technology, compact in structure and simple in wave control system, comprising: a dielectric substrate, a grounded metal plate is arranged on one surface of the dielectric substrate, and a grounded metal plate is arranged on the other surface of the dielectric substrate. There are at least two row-direction microstrip lines and one column-direction microstrip line on one surface, and equally spaced slits are etched on the ground metal plate along a straight line corresponding to each row-direction microstrip line-microstrip slits Antenna; the column microstrip line is connected to one end of the row microstrip line through a DC blocking capacitor, and the other end of the row microstrip line is connected to a matching load through a DC blocking capacitor; one end of the column microstrip line is connected to a DC blocking capacitor Match the load, and the other end is connected to the radio frequency end through a DC blocking capacitor; a row-oriented barium strontium titanate BST strip is arranged between each row-oriented microstrip line and the dielectric substrate, and a column-oriented microstrip line and the dielectric substrate Barium strontium titanate BST strips are also available.

Description

A Simple Single Board Microstrip Slot Phased Array Antenna for Wave Steering System

1. Technical field:

The invention relates to a single-board microstrip slot phased array antenna based on single-board system integration technology, compact structure and very simple wave control system. The antenna can be used for portable low-cost millimeter-wave real-time imaging and radar systems.

2. Background technology

Antenna is an essential and important part of systems such as radar, millimeter wave imaging and wireless communication. The beam pointing of the antenna transmitting or receiving electromagnetic waves requires regular movement in many applications (such as target search radar or millimeter wave scanning imaging system) , that is, scan. The scanning of the antenna beam can be realized by means of mechanical driving, and also can be realized by means of electrical control. Mechanical scanning is the beam scanning realized by the mechanical movement of the antenna according to the instruction. The scanning rate of the antenna is not high, which affects the data transmission rate, and the precise scanning of the beam needs to overcome the inertia of the mechanical movement, especially the larger size and mass of the antenna. so it is. The electronic scanning antenna does not make mechanical movement, and the transmitting or receiving beam of the antenna can change the direction without inertia in the set airspace, and the scanning rate is also greatly improved.

The inherent advantages of electronically scanned antennas make them play a pivotal role in radar and millimeter-wave imaging systems. Taking millimeter-wave imaging as an example, in addition to electronic scanning imaging, there are also imaging methods such as mechanical scanning imaging and staring focal plane array imaging, but these two imaging methods have insurmountable shortcomings. Mechanical scanning imaging uses a mechanical device to drive the sensor to scan the focal plane of the imaging antenna, or drive the entire antenna to scan the far field. The main disadvantage of this scanning method is that the moving speed of the mechanical device is difficult to ensure real-time imaging, and the mechanical scanning device Existence reduces the portability of the system; while the staring focal plane array is similar to the CCD of a household digital camera, in theory, this system needs to have multiple receivers equal to the number of elements of the focal plane array, so that the entire focal plane array can be imaged The cost of the system is quite expensive. If electronic scanning imaging is adopted, the number of receivers can be greatly reduced or even only one receiver can be used, cost can be effectively controlled, and real-time imaging can be achieved. In the radar system, the phased array antenna, an outstanding representative of the electronic scanning antenna, plays an irreplaceable role. At present, the highest level of military radars in various countries are phased array radars.

The traditional phased array antenna system is composed of a large number of phase shifters (Phase shifter-PS) and antennas (Antenna) connected to each other. These phase shifters are independent devices, except for connecting radio frequency (Radio Frequency-RF) lines In addition, they are also connected to their own beam control lines (Control Line-CL) and connected to the beam controller (BeamController), which makes the traditional phased array system complex, low integration, poor portability, and expensive.

Utilizing the dielectric tunability of ferroelectric materials (for example: barium strontium titanate Ba _x Sr _1-x TiO ₃ -BST) under the action of DC voltage, electrical tuning elements with excellent performance can be produced. Compared with semiconductor tubes, iron Oxygen and MEMS devices, this BST-based electrical adjustment element has the characteristics of low power consumption, low cost, and high reliability. The dielectric tunability of BST is used in phased array design, and new phased arrays with excellent structure and performance can be designed. The present invention is based on BST materials, combined with an integrated antenna array, and proposes a novel and simple phased array structure. The beam control system of the phased array antenna designed with this structure is very simple, and the whole system is integrated on a PCB board On (System onBoard-SoB), the high level of integration is conducive to the miniaturization and weight reduction of the entire imaging or radar system.

3. Contents of the invention:

The invention relates to a single-board microstrip slot phased array antenna based on single-board system integration technology, compact structure and simple wave control system. The antenna can be used for portable, low-cost millimeter-wave real-time imaging and radar systems. The feature of this phased array antenna is that the phase shifter in the system is organically combined with the antenna array, so that the entire antenna system can be integrated on a single PCB, and the beam scanning control system is very simple.

The present invention adopts following technical scheme:

A single-board microstrip slot phased array antenna with a simple wave control system, comprising: a dielectric substrate, a grounded metal plate is arranged on one surface of the dielectric substrate, and at least two row directions are arranged on the other surface of the dielectric substrate. Microstrip line and a column-oriented microstrip line, etch equally spaced slots on the grounded metal plate along a straight line corresponding to each row-oriented microstrip line-microstrip slot antenna, and the column-oriented microstrip line passes through the DC-isolated The capacitors are respectively connected to one end of the row microstrip line, the other end of the row microstrip line is respectively connected to a matching load through a DC blocking capacitor, one end of the column microstrip line is connected to a matching load through a DC blocking capacitor, and the column to the microstrip line is connected to a matching load through a DC blocking capacitor. The other end of the line is connected to the radio frequency end through a DC blocking capacitor. A row-oriented barium strontium titanate BST strip is respectively set between each row-oriented microstrip line and the dielectric substrate, and a row-oriented barium strontium titanate BST strip is arranged between each column-oriented microstrip line and the dielectric substrate. There are barium strontium titanate BST strips. When no voltage is applied between the microstrip line and the ground plane, there is an initial column-phase phase difference δ _y between the electromagnetic signals of every two adjacent row-to-row microstrip lines, and at the same time, along each row-to-microstrip The electromagnetic signal between two adjacent microstrip slot antennas that propagate through the line and couple to the corresponding straight line of the ground plane also has an initial row phase difference δ _x , so that the antenna array produces a beam pointing corresponding to δ _y and δ _x . When a DC voltage V ₂ is applied between the microstrip line and the grounded metal plate in each row and a DC voltage V ₁ is applied between the microstrip line and the grounded metal plate in the column, the row to barium strontium titanate BST strip and the column As the dielectric constant of the barium strontium titanate BST strip changes, the propagation speed of the electromagnetic signal changes accordingly, causing δ _x and δ _y to change accordingly, to δ _x + Δδ _x and δ _y + Δδ _y , Δδ _x is the variation of the phase difference in the row direction, and Δδ _y is the variation of the phase difference in the column direction. At this time, the antenna generates the beam pointing corresponding to δ _x + Δδ _x and δ _y + Δδ _y , so as to achieve the purpose of beam scanning.

Compared with prior art, the present invention has following advantage:

With an extremely simple beam control system, for an M×N array, no matter what the values of M and N are, only two beam control lines are needed to realize two-dimensional scanning of the beam—that is, two voltage control lines, while a traditional An M×N array phased array antenna requires M×N beam control lines (for example, the 3×3 array shown in Figure 1 requires a total of 9 beam control lines). Usually, the phased array has thousands or even tens of thousands of units, that is to say, tens of thousands of beam control lines are required, which seriously affects the simplicity and cost of the system; The scan control only needs two voltage control lines, the system is simple and the cost is saved. In addition, the microstrip line part located on the BST film in the present invention is not only a part of the phase-shifting circuit structure, but also plays the role of connecting the antenna, so that the entire phased array structure forms a quasi-seamless connection, which is beneficial to reduce system volume and weight, and make the present invention compact. However, in a common phased array system, each phase shifter needs its own independent control line, and each phase shifter cannot be connected as a whole like the phase shifting part in the present invention, and form a quasi-seamless connection with the antenna.

The content involved in the present invention is of great significance not only for developing a low-cost, portable electrical scanning millimeter-wave imaging system, but also for developing a low-cost, compact electrical scanning radar antenna.

4. Description of drawings

FIG. 1 is a schematic diagram of beam steering of an existing common phased array.

Fig. 2 is a schematic diagram of the two-dimensional phased array of the present invention.

Fig. 3 is a structural schematic diagram of the present invention.

Figure 4 is a schematic diagram of a microstrip slot antenna on a ground plane.

5. Specific implementation

A single-board microstrip slot phased array antenna with a simple wave control system, comprising: a dielectric substrate 1, a grounded metal plate 6 is arranged on one surface of the dielectric substrate 1, and at least Two row-direction microstrip lines 3 and one column-direction microstrip line 2 are etched on the ground metal plate 6 along a straight line corresponding to each row-direction microstrip line to etch equally spaced slots—microstrip slot antennas 12, The column microstrip line 2 is respectively connected to one end of the row microstrip line 3 through a DC blocking capacitor 8, and the other end of the row microstrip line 3 is respectively connected to a matching load 9 through a DC blocking capacitor 8. The column microstrip line One end of 2 is connected to a matching load 9 through a DC blocking capacitor 8, the other end of the column microstrip line 2 is connected to the radio frequency terminal 10 through a DC blocking capacitor 8, and each row microstrip line 3 and the dielectric substrate 1 are respectively set There are row barium strontium titanate BST strips 4 , and column barium strontium titanate BST strips 11 are arranged between the column microstrip line 2 and the dielectric substrate 1 . When no voltage is applied between the microstrip line and the ground plane, there is an initial column-phase phase difference δ _y between the electromagnetic signals of every two adjacent row-to-row microstrip lines, and at the same time, along each row-to-microstrip The electromagnetic signal between the two adjacent microstrip slot antennas 1 propagating on the line 3 and coupled to the corresponding straight line of the ground plate 6 also has an initial row-wise phase difference δ _x , so that the antenna array generates a corresponding to δ _y and δ _x beam pointing. When a DC voltage V 2 is applied between the microstrip line 3 and the ground metal plate ₆ in each row and a DC voltage V 1 is applied between the microstrip line 2 and the ground metal plate ₆ in the column, the row direction barium strontium titanate The dielectric constant of the BST strip 4 and the columnar barium strontium titanate BST strip 11 changes, and the propagation speed of the electromagnetic signal changes accordingly, so that δ _x and δ _y change accordingly, changing to δ _x + Δδ _x and δ respectively _y +Δδ _y , Δδ _x is the amount of change in the phase difference in the row direction, and Δδ _y is the amount of change in the phase difference in the column direction. At this time, the antenna generates a beam pointing corresponding to δ _x + Δδ _x and δ _y + Δδ _y , so as to achieve Purpose of beam scanning.

The key to realizing this two-dimensional phased array structure is to realize the isolation of AC and DC signals, the parallel connection between the DC power supply V ₁ and the column microstrip line 2, the different row microstrip lines 3, and the row microstrip line 3 After parallel connection, the connecting line with the DC power supply V ₂ adopts a high-frequency serpentine line 7 through DC resistance to prevent the mutual influence of the AC signals transmitted between the row microstrip lines 3 and the leakage of the AC signals to the DC circuit; the row direction microstrip Between the line 3 and the radio frequency terminal 10, between the row microstrip line 3 and the matching load 9, between the row microstrip line 3 and the column microstrip line 2, and between the column microstrip line and the matching load 9 A DC blocking capacitor 8 for blocking DC and high frequency is provided to prevent the DC signal from leaking to the AC circuit. The matching load 9 is used to absorb a small amount of electromagnetic waves that are not radiated out, so as to prevent adverse effects of reflected waves at the end.

Claims (1)

1. A single-board microstrip slot phased array antenna with a simple wave control system, comprising: a dielectric substrate, a grounded metal plate (6) is provided on one surface of the dielectric substrate, and a grounded metal plate (6) is provided on the other surface of the dielectric substrate. At least two row-direction microstrip lines (3) and one column-direction microstrip line (2), etch equally spaced slits on the ground metal plate (6) along a straight line corresponding to each row-direction microstrip line -Microstrip slot antenna (12), the column microstrip line (2) is respectively connected to one end of the row microstrip line (3) through a DC blocking capacitor (8), and the other end of the row microstrip line (3) passes through DC blocking capacitors (8) are respectively connected to matching loads (9), one end of the column-to-microstrip line (2) is connected to the matching load (9) through a DC-blocking capacitor (8), and the other end of the column-to-microstrip line (2) One end is connected to the radio frequency end (10) through a DC blocking capacitor (8), and a row direction barium strontium titanate BST strip (4) is respectively arranged between each row direction microstrip line (3) and the dielectric substrate (1), A column-oriented barium strontium titanate BST strip (11) is provided between the column-oriented microstrip line (2) and the dielectric substrate (1). When no voltage is applied between the microstrip line and the ground plate, every two adjacent There is an initial column-phase phase difference δ _y between the electromagnetic signals of the row-toward microstrip lines, and at the same time, propagate along each row-towards microstrip line (3) and couple to the two corresponding straight lines of the ground plate (6). The electromagnetic signals between adjacent microstrip slot antennas (1) also have an initial row phase difference δ _x , so that the antenna array produces a beam pointing corresponding to δ _y and δ _x ; when each row direction microstrip line (3) After applying a DC voltage V ₂ between the ground metal plate (6) and applying a DC voltage V ₁ between the column microstrip line (2) and the ground metal plate (6), the row direction barium strontium titanate BST The dielectric constant of the bar (4) and the barium strontium titanate BST bar (11) changes, and the propagation speed of the electromagnetic signal changes accordingly, so that δ _x and δ _y change accordingly to δ _x + Δδ _x and δ _y + Δδ _y , Δδ _x is the amount of change in the phase difference in the row direction, and Δδ _y is the amount of change in the phase difference in the column direction. At this time, the antenna generates a beam pointing corresponding to δ _x + Δδ _x and δ _y + Δδ _y , so as to achieve the purpose of beam scanning.

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