A 1.2 to 5.7GHz Multi-Mode Dual-Input Power Amplifier using a Novel Sigmoid-Function-Based Power Splitter

We report a novel power splitting scheme for multi-mode dual-input power amplifier at sub-6GHz. The main novelty is the use of a sigmoid function to enable multi-mode load modulation over a wide frequency range with a modulated signal. One input signal is converted to two inputs based on the sigmoid function, which provides optimum signal magnitude and phase of dual input signals. The amplifier, using 0.15┬Ám GaN HEMT FETs, achieved an averaged PAE of 36-56% with a modulated signal over 1.2-5.7GHz, which is 130% fractional bandwidth. This is a promising PA technology for 5G base stations, enabling operators to reduce their total cost of ownership.