A New Emitter-Base-Collector-Base-Emitter SiGe HBT for High Power, Single-Pole Double-Throw X-Band Switches

This letter proposes a new emitter-base-collector-base-emitter (EBCBE) SiGe HBT suited for high power RF switches. Two collector-base-emitter (CBE) SiGe HBTs are merged into a single EBCBE SiGe HBT, not only to double its maximum voltage swing, but also to decrease its active area and parasitics. To further boost its power handling, a capacitive voltage distribution and a collector floating are incorporated into the new EBCBE SiGe HBT. A X-band λ/4 shunt single-pole-double-throw (SPDT) switch using the EBCBE SiGe HBT achieves measured insertion losses and isolations of 1.2/1.3 and 29.2/23.0 dB at 10 GHz in TX/RX modes, respectively. In TX mode, measured input 1-dB power compression ( P_1dB) is 25.4 dBm, and it can be extended to 28.5 dBm at -0.6 V base bias of the EBCBE SiGe HBT.