RF Coaxial Switch

Principle of coaxial Switch device

The principle of ferrite switch is to change the direction of bias magnetic field, realize the change of permeability, change the transmission constant of the signal to achieve the switch purpose.

The pin tube has a switching effect on the microwave signal under the action of the positive and negative low frequency signal. The attenuation of the microwave signal is very small (0.5dB) in the forward bias, and the attenuation of the microwave signal is very large (25dB) when the reverse bias is placed.

The principle of the BJT and FET switches is the same as for low frequency transistor switches, and the control signal of the base (gate) determines the switching of the Collector (drain) and emitter (source). Amplifier has gain, reverse isolation large, especially suitable for mmic switch.

MEMS micro-mechanical circuit is a new device developed in recent years, it can also be used as a switching device.

Microwave Switch circuit

The combination of the switching device and the microwave transmission line constitutes the microwave switch assembly. The equivalent circuit of the connection form of various switching devices and microwave circuits. The switch is defined by the number of interfaces, codenamed #p#t, such as Spst (SPST), SPDT (SPDT), double-throw (DPDT), SPDT (sp6t), etc.

The microwave design of these circuits should consider the parasitic parameter design matching network of the switch, and also consider the installation size of the device.