Ku-Band Cascode Balanced SiGe Power Amplifier with High Robustness to Active SWR

This paper presents the first efficient Ku-Band SiGe cascode power amplifier (PA) with a highly robust power combination to the active SWR. Two twisted couplers distribute 70.2um2 emitter area in a balanced architecture to achieve reduced impedance transformation through baluns. As proof of concept, the PA was simulated with the 0.13-um SiGe BiCMOS technology. The post layout simulations show a saturated power (Psat) of 25.6dBm and a peak PAE of 30% at 18GHz and 90°C. With a 2:1 SWR the PAE and Pout drop less than 5.5% and 1.1dBm, respectively.