Design and fabrication of multiband p-i-n diode switches with ladder circuits

Single-pole double-throw switches composed of p-i-n diodes are proposed for multiband operations. A ladder resonance circuit is introduced to simplify their configuration and to reduce the cost. The isolation greater than 20 dB and the insertion loss less than 2 dB are achieved in experiments at three frequency bands: 1.6, 2.5, and 5.8 GHz. Resonance frequency variations are investigated in detail for two types of switches consisting of: 1) lumped circuit elements and 2) semimicrostrip elements. The variations on the semimicrostrip configuration are about 25% of those with lumped circuit elements. The proposed switch does not influence the switching speed and signal distortion characteristics. It also showed good temperature stability from -30°C to +85°C.