Symmetrical Multiport mmWave Chalcogenide Phase-Change RF Switches

This article demonstrates ultra-compact multiport chalcogenide phase-change germanium telluride (GeTe)-based RF switches. RF series switches in a single-pole single-throw (SPST), single-pole double-throw (SPDT), single-pole triple-throw (SP3T), and a single-pole eight-throw (SP8T) are developed in-house using an eight-layer microfabrication process. The devices are designed with design symmetry to achieve consistent RF performance across all output RF ports. All the multiport switches have chip area less than 0.36 mm
²
including all the RF and DC terminals. The SPST, SPDT, and SP3T switches are measured over DC to 67 GHz with less than 0.25 for SPST and lower than 1 dB loss for SPDT and SP3T, respectively. The SP8T switch is measured from DC to 40 GHz with loss lower than 1.5 dB and isolation better than 20 dB.