A ku‐band distributed SPDT switch in 0.5 μm AlGaN/GaN HEMT technology

Abstract

AbstractIn this paper, a wideband single‐pole double‐throw (SPDT) switch using the traveling‐wave concept was demonstrated. Realized in 0.5 μm AlGaN/GaN HEMT process, it achieves good performance at Ku‐band despite the process being intended for low‐frequency applications. This type of switch combined the off‐state shunt transistors and series coplanar waveguide (CPW) lines to form an artificial transmission line. CPW is also used to eliminate parasitics associated with through‐substrate microstrip vias and coupling of adjacent transmission lines. An accurate switch HEMT model was extracted and used in the design. A 9–25 GHz single‐pole double‐throw (SPDT) switch in conjunction with quarter‐wavelength impedance transformers demonstrates an insertion loss of less than 6 dB, return loss better than 10 dB and an isolation of better than 25 dB.