VO 2 -based Transmit/Receive Switch

This paper presents a transmit/receive (T/R) switch using vanadium dioxide (VO 2 )-based RF switches. The switch employs a 0-dB coupler and two VO 2 -based switches. The T/R switches self-actuate directing the low power from the antenna port to the receive port and the high power from the transmit port to the antenna port. The T/R switch is capable to handle relatively high power levels since the VO 2 switches do not see directly the total transmit power. Other features of the proposed switch are that it consumes no dc power and offers high isolation between the transmit and receive ports in comparison with existing T/R switches. Another key feature of the proposed T/R switch is that the RF power level that switches the unit to the transmit mode can by controlled by a dc bias voltage. A T/R switch has been designed fabricated and tested demonstrating an isolation of over 40 dB.