US Patent 7138885 Transmit receive switch with high power protection

Microwave switch (MS) comprising an antenna branch (AB), a receive branch (RB), and a transmit branch (TB). According to one embodiment, the switch comprises a protection circuit (CPL, DTC, CTRL), which upon a high power signal (Dtc_h) being present on the antenna branch effectuates a biasing of semiconductors on both the receive branch (RB) and the transmit branch (TB). According to one embodiment PIN diodes are provided for controlling switching between the transmit and the receiv branch as well as enabling a protective mode, the control being accomplished by selectively biasing respective diodes.