NanoMount Switches For Microwave Applications

This MicroNOTE was written to help switch designers interface Microsemi's NanoMount PIN diode assemblies with the bias (control) circuits and to understand the DC power requirements of the bias circuits used to turn the PIN diodes on and off.

The first section of this MicroNOTE is an introduction to silicon PIN diode RF control circuits with an emphasis on the RF power switching function.

The discussion starts with the basic PIN diode equivalent circuit parameters that relate to the PIN diode switch performance characteristics in VHF band. Both the control (DC bias) and RF power aspects are discussed in detail.

Next we discuss how these switch circuits and circuit elements change as operating frequencies increase from VHF to 2GHz and finally, beyond 2GHz to the present WLAN bands (2.4GHz to 5.8GHz).

We then present three types of NanoMount assemblies that Microsemi Corproation offers the microwave industry. The major RF and biasing features of these assemblies are emphasized and performance is provided.

Finally, we look at some methods to broadband the RF and bias circuits, the treatment of resistive loss in switch circuit elements, and the importance of reliable electrical grounding for all shunt elements in the switch design.