CN104409855A - Novel phased-array antenna - Google Patents

Abstract

The invention provides a novel phased-array antenna which comprises antenna radiation components arranged on a PCB board and a phase shift feed network, wherein the radiation components are arranged on the upper surface of the PCB board in an array manner, and the phase shift feed network is arranged at the middle layer of the PCB board and adopts liquid crystal as a voltage-controlled phase shift material; every line or every column of array type radiation components are connected through microstrip lines, and phase shift chips are arranged among very line or every column of microstrip lines; liquid crystal areas of the phase shift feed network are uniformly and symmetrically arranged in the array of the radiation components. The novel phased-array antenna adopts liquid crystal phase shift to achieve a phase shift effect; the liquid crystal is manufactured in the laminated PCB board, so that manufacture is convenient, and beam scanning can be realized; therefore, positioning can be realized through a single radio frequency link, the system deployment is greatly simplified, and the cost is reduced; the liquid crystal phase shift and the phase shift chips are combined to realize two-dimensional scanning of beams, so that a lot of traditional phase shift networks are reduced, and the reliability of equipment in the running process is improved.

Description

New Phased Array Antenna

technical field

The invention belongs to the communication field, in particular to a phased array antenna using new materials.

Background technique

ETC free flow belongs to the field of highway monitoring and management. The application frequency band is 5800MHz. The application scenario is urban roads. The reader is set up on the gantry of the road and communicates with the vehicle-mounted unit of the car. It can monitor the vehicle and know the location information of the vehicle through communication. , capable of monitoring and managing vehicle violations. Since the actual lane is relatively narrow, only 3.4 meters, if you want to accurately know the location information of the vehicle, you need to control the positioning accuracy within a small range, so how to accurately locate becomes the most important issue in the system , and the premise of accurate positioning is how to design an antenna with simple structure and low cost.

Contents of the invention

The problem to be solved by the present invention is to provide a phased array antenna with simple structure and low cost.

In order to solve the above problems, the technical solution adopted by the present invention is: a novel phased array antenna, including an antenna radiating part and a phase-shifting feeding network, and the antenna radiating part and the phase-shifting feeding network are all arranged on a PCB board , the antenna radiating components are arranged in an array on the upper surface of the PCB, the phase-shifting feed network is arranged on the middle layer of the PCB, the phase-shifting feed network uses liquid crystal as a voltage-controlled phase-shifting material, and the array Each row or column of the antenna radiating parts is connected by a microstrip line, and a phase-shifting chip is connected between each row or column of microstrip lines through a microstrip line, and the liquid crystal area of the phase-shifting feed network is uniform and symmetrical The ground is arranged in the array of antenna radiating elements.

The lower surface of the PCB board is an antenna ground layer.

Each row and/or each column of the array of antenna radiating elements has an even number of antenna radiating elements. The use of an even number of radiating elements is beneficial to the nature of the antenna beam.

The liquid crystal regions are evenly distributed to both sides with the median line of the even-numbered antenna radiating components as the center. Symmetrical layout, easy to process.

The phase-shifting chip is arranged on the median line of the even-numbered antenna radiating components. This configuration requires the fewest phase shifting devices.

The distance between the antenna radiating components satisfies that there is no interference between the antenna radiating components.

The advantages and positive effects of the present invention are: 1. The present invention adopts the liquid crystal phase shifting method to achieve the effect of phase shifting, and the liquid crystal can be made in the laminated circuit board, which is easy to make, so that beam scanning can be realized, so that The positioning problem is realized through a single radio frequency link, which greatly simplifies system deployment and reduces costs. 2. The present invention adopts the combination of liquid crystal phase shifter and phase shifter chip to realize the two-dimensional scanning of the beam, and the layout of the whole antenna is relatively reasonable, which can reduce a large number of traditional phase shifter networks and improve the operation process of the equipment. in the reliability. 3. This form provides a brand-new method to solve the problem of ETC free flow positioning and expand coverage. It has high positioning accuracy, and only needs a single device to work, with simple structure and low cost.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Fig. 2 is a functional block diagram of the present invention applied to the ETC antenna system;

In the figure: 1 radiating part 2 liquid crystal 3 phase shifting chip 4 PCB board.

Detailed ways

The present invention is described in more detail according to accompanying drawing now, as shown in Figure 1, a kind of novel phased array antenna comprises antenna radiating part and phase-shift feeding network, and described antenna radiating part and described phase-shifting feeding network are all arranged on the PCB board, the antenna radiating parts are arranged in an array on the upper surface of the PCB board, the phase-shifting feeding network is arranged on the middle layer of the PCB board, and the phase-shifting feeding network uses liquid crystal as a voltage-controlled shifting phase material, each row or column of antenna radiating components arranged in array is connected by a microstrip line, and a phase-shifting chip is connected between each row or column of microstrip lines through a microstrip line, and the phase-shifting feed network The liquid crystal regions are uniformly and symmetrically arranged in the array of antenna radiating components.

The lower surface of the PCB board is an antenna ground layer.

Each row and/or column of the antenna radiating element array has an even number (6 in this embodiment) of antenna radiating elements.

The liquid crystal regions are evenly distributed to both sides with the median line of the even-numbered antenna radiating components as the center.

The phase-shifting chip is arranged on the median line of the even-numbered antenna radiating components.

The antenna radiating part of the present invention, because the non-parking toll collection system has a high operating frequency, and the thickness of the equipment installation is relatively small, we adopt the form of microstrip line connection, and adopt foreign imported plates. It can be seen from the figure that the radiating parts of each antenna are exactly the same. The antenna port adopts an SMA connector and is connected to the radio frequency channel of the radio frequency circuit board through a radio frequency cable. This ETC antenna system is just one of our application methods, and the method of this patent application can adopt many other forms. The number of antenna radiating components can also be adjusted according to actual positioning requirements.

As shown in Figure 1, the phase-shifting feed network of the present invention is relatively simple, and the liquid crystal is directly embedded in the laminated PCB as a voltage-controlled material, and the effect of phase change is changed by controlling the voltage of the liquid crystal material, thereby achieving phase shifting effect. After adopting this method, the use of more phase shifters can be avoided, and the cost can be greatly reduced.

The working principle of the ETC antenna system composed of this antenna:

As shown in Figure 2, the ETC phased array antenna system mainly includes an antenna part (including a phase-shifting network), a radio frequency transceiver circuit and a digital processing part. The phase shifting network of this scheme adopts a phase shifter made of a new material (liquid crystal), which can greatly reduce the complexity of the system. The phase shifter uses liquid crystal as a voltage-controlled phase shifting material, and when the signal passes through the liquid crystal region, it will produce a phase deflection. This kind of liquid crystal phase shifter is suitable to be made together with the PCB board and made into a laminated structure, which is convenient for feeding the array antenna, so that it can be made into a relatively simple phased array network, and the liquid crystal phase shifter can be changed by controlling the voltage. Phase, so that the purpose of beam scanning can be achieved. When the beam can scan, the coverage of the beam can be adjusted, and the final incoming signal direction can be known by comparing the beams in multiple directions, so that the purpose of the phased array antenna can be achieved. The transceiver link required by this type of antenna is relatively simple, and only one transceiver link is required. The signal processing part mainly uses FPGA processing, and the signal processing is timely and accurate. In order to achieve the accuracy of beam scanning, the following aspects can be used to effectively control the accuracy of the system.

Multiple antenna radiating parts are used in the antenna design, and the mutual coupling between the antenna radiating parts is ensured to be very small by setting the distance between the antenna radiating parts, so that there is no mutual interference between the radiating parts, so that the antenna radiating parts can be obtained Accurate RF phase difference.

The receiving part of the antenna is exactly the same as the antenna radiating part. The individual performance indicators of these radiating parts are exactly the same, and the working frequency band is also the same. The distance between the antenna radiating parts is relatively close, and it can be installed on an antenna board (PCB board). The main function is that each antenna radiating part can receive radio frequency signals. Since the antenna radiating parts keep a certain distance, the signals received by each antenna radiating part have the same amplitude but different phases. The antenna radiating part and the phase-shifting feed network are made on one circuit board. The phase-shifting feed network adopts the method of liquid crystal phase shifting (as shown in Figure 1). The liquid crystal is directly embedded in the laminated PCB as a voltage control material. By controlling the The voltage of the liquid crystal material changes the effect of phase change, thereby achieving the effect of phase shift. After adopting this method, the use of more phase shifters can be avoided, and the cost can be greatly reduced. Compared with the phase shifting in the digital domain, many radio frequency channels can be reduced, and the cost can also be reduced. Combining liquid crystal phase shifting with traditional phase shifter chips (this antenna includes both liquid crystal phase shifting and phase shifting chip phase shifting) can be made into a 2-dimensional beam scanning antenna, so that the radio frequency link only needs A radio frequency link can greatly reduce the cost.

The RF receiving circuit in the RF link mainly converts the signal received by the antenna into an intermediate frequency signal through down-conversion, and then passes through the intermediate frequency amplifier circuit and AD sampling to amplify the signal, and then sends it to the logic chip after AD sampling ( In the FPGA chip of the digital processing part), subsequent signal processing can be performed.

The RF transmission circuit in the RF link mainly converts the digital signal output by the logic chip into an analog signal through DA conversion, and then becomes a RF signal after intermediate frequency amplification and up-conversion, and then radiates out through the antenna.

The digital processing part is mainly responsible for processing the received signal and controlling the scanning state of the beam. The phase of the liquid crystal phase shifter can be changed by controlling the voltage, so that the purpose of beam scanning can be achieved. When the beam can scan, the coverage of the beam can be adjusted, and the final incoming signal direction can be known by comparing the beams in multiple directions.

The embodiments of the present invention have been described in detail above, but the content described is only a preferred embodiment of the present invention, and cannot be considered as limiting the implementation scope of the present invention. All equivalent changes and improvements made according to the scope of the present invention should still belong to the scope of this patent.

Claims (6)

1. a novel phased array antenna, it is characterized in that: comprise antenna radiating element and phase shift feeding network, described antenna radiating element and described phase shift feeding network are all arranged on pcb board, described antenna radiating element array is arranged at the upper surface of pcb board, described phase shift feeding network is arranged at the intermediate layer of pcb board, described phase shift feeding network adopts liquid crystal as shift phase by voltage controlled material, every a line of antenna radiating element that described array is arranged or each row are connected by microstrip line, phase shift chip is connected with by microstrip line between every a line or each row microstrip line, the liquid crystal region of described phase shift feeding network evenly and be arranged at symmetrically in the array of antenna radiating element.

2. novel phased array antenna according to claim 1, is characterized in that: the lower surface of described pcb board is antenna stratum.

3. novel phased array antenna according to claim 1, is characterized in that: described antenna radiating element array is often gone and/or is often classified as even number of antenna radiation component.

4. novel phased array antenna according to claim 3, is characterized in that: described liquid crystal region is uniformly distributed to both sides centered by separated time in described even number of antenna radiation component.

5. novel phased array antenna according to claim 4, is characterized in that: described phase shift chip is located on the middle separated time of described even number of antenna radiation component.

6. the novel phased array antenna according to any one of claim 1-5, is characterized in that: the distance between each described antenna radiating element meets between each antenna radiating element and there is not interference.