Impact of the Doped Areas Sizes in the Performances of Microwave SPST Switches Integrated in a Silicon Substrate
Résumé
This paper deals with the impact of the doped areas sizes on the performances of microwave switches. The RF switches are designed on a silicon substrate in microstrip technology and use semiconductors diodes (N+P junctions) as active elements to commute from the OFF-state to the ON-state. Therefore, the co-design of the microstrip transmission lines and the active elements gives a great design flexibility. The manufacturing process is based on classical steps used to fabricate semiconductor components and this allows to choose the size of the active elements (i.e. the size of the doped areas). Five demonstrators with as many different integrated diode sizes are presented and the size impact on their performances is discussed on the frequency band going from 0.1 GHz to 10 GHz. With a very low bias voltage, the insertion losses are lower than 2 dB and the isolation can be higher than 40 dB.