Enhancing Linear Output and Stability in Class C UHF Power Amplifiers using Coplanar Waveguide Impedance Matching

The design and development of a Power Amplifier (PA) operating within the Ultra High Frequency (UHF) range, specifically targeting applications that require high efficiency and stability, such as handheld transceivers, satellite, IoT, 5G base stations is presented. The amplifier, which uses a Class C topology, was designed to generate continuous output power between 400 MHz and 500 MHz while maintaining an efficiency of more than 70%. Key advancements include the use of a feedback network to ensure unconditional stability and the optimization of linearity to reduce harmonic emissions. Simulations and hardware testing demonstrated improvements. The results demonstrate the effectiveness of the applied techniques in balancing efficiency and linearity for UHF PA applications.