A 28GHz, Switched-Cascode, Class E Amplifier in 22nm CMOS FDSOI Technology

Using the stacking technique in CMOS technology for Power Amplifiers (PAs), allows the use of a higher supply voltage. This facilitates achieving a higher voltage swing, and delivering more output power while maintaining a high efficiency. This work presents an improved 2-stacked cascode class-E PA at 28 GHz. Unlike existing topologies, a switching input signal is not only applied at the input transistor, but also at the cascode transistor with an added delay. The design was fabricated in 22 nm FDSOI CMOS technology by GlobalFoundries that offers high performance especially at mm-wave frequencies. Measurement results of the cascode Class-E Power Amplifier achieves a peak PAE of 28%, and 41% DE. The switched-cascode topology showed an improved peak PAE of 35% and DE of 45%. Measured power gain was 8.5 dB with saturated output power (Psat) of 13 dBm. This work reports the best Drain Efficiency (DE) and FoM for a fully integrated PA at 28 GHz in 22 nm FDSOI.