A S-C- / K-band Reconfigurable GaAs MMIC Power Amplifier for 5G Applications

This work presents a power amplifier design approach for frequency reconfiguration between two arbitrarily-spaced bands. The method uses two parallel matching networks whose designs are de-coupled through the topology choice. The low-band matching network is constrained to consist of a shunt reactive element connected through quarter-wavelength transmission lines at the higher frequency. A shunt switch is placed in parallel to the matching reactance to enable isolation of this path from the high-frequency response when the switch is on. The architecture is demonstrated in a GaAs MMIC operating at C and K bands appropriate for a multi-function 5G transmitter. In CW operation at 5.8 / 22 GHz, the power amplifier achieves a power-added efficiency of 29.5 / 28 % with a corresponding output power of 20 / 20.5 % dBm and a single-stage gain of 8 / 6 dB. The amplifier is characterized with a 100-MHz LTE-like signal over a 2.8-6.8 and 18-23 GHz range.