With the development of modern wireless communication system, mobile communication, radar, satellite communications and other communication systems on the transceiver switch switch speed, power capacity, integration and other aspects of a higher demand, so the study of VXI bus technology,RF Switch Side special requirements of the VXI bus module, has a very important significance.
With the development of modern wireless communication system, mobile communication, radar, satellite communications and other communication systems on the transceiver switch switch speed, power capacity, integration and other aspects of a higher demand, so the study of VXI bus technology, Side of the special requirements of the VXI bus module, has a very important significance, we will use the virtual instrument ideas, the hardware circuit to achieve the software, the following design of the RF Switch can be directly controlled by the computer can be easily with the VXI bus test system Integration, the maximum play computer and microelectronics technology in today's test field applications, has broad prospects for development.
Usually the RF system has many inputs and outputs of the port,RF Switch the microwave switch can be multi-input multi-output signal to switch, although a number of parameters and RF and microwave switch performance, but the following four because of their strong correlation between each other But is considered a critical parameter: isolation, insertion loss, switching time, power handling capability.
The degree of isolation between the circuit input and the output is the measure of the effectiveness of the cut-off.
Insertion loss (also called transmission loss) is the total power dissipation when the switch is on. Since the insertion loss can directly lead to an increase in the system noise figure, the insertion loss is the most critical parameter for the designer.
The switch time is the time required for the switch to transition from the "on" state to the "off" state and from the "off" state to the "on" state. The most common definition of switching time is the time required for the input control voltage to reach 50% of its final RF output power to 90%. In addition, the power handling capability is defined as the maximum RF input power that the switch can withstand without any permanent electrical performance degradation.
RF and microwave switches can be divided into electromechanical relay switches and solid state switches two categories. These switches can be designed for a variety of different configurations - from single-pole single-throw to single-pole, six-throw, or more-throw configurations that can convert a single input into 16 different output states. The switch is a double pole double throw configuration switch. This type of switch has four ports and two possible switch states, which allow the load to switch between the two sources.
However, in the operation of electromechanical RF Switches, there are some problems worthy of our attention. The standard service life of these switches is only about 1 million times, and its components are more sensitive to vibration. The service life is the number of times the electromechanical switch can complete the RF and repeatability requirements. High quality or high reliability Electromechanical switches are ideal for applications where longer service life is required. The reliability and other performance of this type of switch is extremely superior, and the service life of up to 10 million times. The longer service life comes from the design of a more robust actuator and a more optimized drive link for magnetic and mechanical rigidity. In addition, such switches are designed to withstand more severe environmental conditions and meet the requirements of the MIL-STD-2002 standard for both sinusoidal and random vibration and mechanical shocks.