In this paper, thermostatic element a new ATE microwave controller is designed and developed to automate the control and connection of various ATE RF circuits. According to the overall design scheme of ATE microwave controller and the actual requirements of radio frequency control of ATE microwave controller, the overall architecture, hardware structure and conditioning circuit of ATE microwave controller are planned, and the software control coding design is illustrated by an example. Practice results show that the microwave controller has low radio frequency transmission loss and high switching accuracy. It can realize the high precision connection between ATE system and the RF instrument resources of the microwave controller and the measured RF equipment. In the current technology market, ATE system is very popular among many large-scale airborne electronic equipment systems. ATE test can be divided into video test, radio frequency test, high frequency test and low frequency test according to different test methods. A new type of microwave controller is studied and designed. The ATE system can connect the RF instrument resources of the microwave controller to the RF equipment under test by means of remote operation. The new controller takes industrial computer as the key component and digital I/O control as the basis. It uses special notebook built-in interface card to control each module and complete various tests and system debugging.
The industrial computer connects the chassis with a special main chassis, and uses 1394 bus to realize the communication between key components and VXI controller, so as to achieve the goal of programmable control. Using VMIP interface and VM digital module, the link control between each module and chassis is completed. The microwave controller can automatically switch the RF port signal by remote control. The selection of microwave coaxial switch should consider isolation ability, insertion loss, reliability and other factors. Compared with common coaxial switches, Agilent coaxial switches have the advantages of small interpolation loss, large isolation between adjacent channels, high reliability on-off operation and fast operation speed. Shanghai Huaxiang single-pole double-throw coaxial switch has the characteristics of high throughput tolerance and high power radio frequency. Therefore, two kinds of switches are selected to match reasonably and use optimally in microwave test.
K1 and K 2 choose Shanghai Huaxiang SHX-801001-F-S coaxial switch. K3 and K 4-K 6 choose Agilent 8766-8767 coaxial switch respectively. At the same time, a 250W 30dB RF attenuator is designed to control the attenuation of high RF power signal power and to ensure the safety of each component and instrument in a certain range. The control coding design of coaxial switches in microwave controller consists of six components: an external clock CLK control needle, an I/O control needle and a DATA x.
0-7. A new microwave controller is designed, which combines the above switches to form a new microwave controller by using a combination of the correct level drive to ensure the reliability of the connection between the testing instrument and COM terminals. As shown in Fig. 2, high levels are applied to the K 1 and K 2 control terminals, and the switch common terminals are selectively linked to the NO and NC terminals.
As shown in Table 1, the selection control is not unique because of the high level applied to the K3-K6 control terminal.
In the overall structure layout design, the controller is divided into two large areas, namely switch area and other circuit areas. It is also divided into conditioning circuit, power supply, microwave control area and other different functional areas.
Compared with other controllers, the microwave controller has obvious advantages of high radio frequency transmission accuracy, easy installation and maintenance, and high anti-interference. The debugging of the controller is completed by switching power supply, multimeter and radar synthesizer.
By analyzing the matching load resistance value of attenuator, using multimeter to measure the on-resistance value of each port, line and circuit after conversion operation, the coding control and debugging methods of each port and line of two types of switching power supply are tested and analyzed. Through the test results, we find that the design scheme can meet the basic requirements of the controller and has high feasibility; the single input current of the debugging circuit is much lower than the single output capacity value; the debugging circuit reduces the driving demand for I/O obviously, and enhances the stability and reliability of the module.
The maximum driving current of the microwave switch provided by the conditioning circuit can reach 130 mA, which meets the driving requirement of Agilent microwave switch.
The microwave controller has low radio frequency transmission loss and high switching accuracy. It can realize the high precision connection between ATE system and the RF instrument resources of the microwave controller and the measured RF equipment.
The design scheme has high operability and can provide theoretical basis and reference significance for market production.