A novel Q‐band asymmetric T/R switch in GaAs pHEMT using second‐order band‐stop filter for wideband RX‐mode isolation

To improve the RX‐mode isolation of asymmetric T/R switches, a new circuit topology is proposed. The proposed asymmetric T/R switch topology features a second‐order band‐stop filter in its TX path, which extends the bandwidth of isolation in the RX mode. Based on the proposed topology, a Q‐band asymmetric T/R switch is designed and implemented in a 0.15‐µm GaAs pHEMT technology. Measured isolation in the RX mode is greater than 18.4 dB from 31.7 to 46.3 GHz, corresponding to a 1.46:1 bandwidth.