Multi-Octave GaN MMIC Circulator for Simultaneous Transmit Receive Applications

This paper presents a microwave implementation of the novel sequentially-switched delay line (SSDL) for simultaneous transmit and receive (STAR) applications. The circuit is non-reciprocal and non-magnetic and is implemented in a high frequency GaN MMIC process. It isolates the transmit and receive paths. Measurements confirm the non-reciprocal nature of the circuit. The insertion loss is 5–8 dB with 20–35 dB isolation over DC–2 GHz.