p-i-n-Diode-Based Four-Channel Switched Filter Bank With Low-Power TTL-Compatible Driver

The design of a four-channel switched filter bank in the S- and C-band using p-i-n-diode switches is described. Narrowband filters (3.2%-3.5%) are designed on suspended substrate stripline. The biasing circuit allows the switches to be driven with transistor-transistor-logic-compatible voltages and minimum biasing current. The average insertion loss measured is 3.6 dB corresponding to a Q-factor of 580. Spurious responses were suppressed from dc to roughly 19 GHz.