Codesign of High-Efficiency Power Amplifier and Ring-Resonator Filter Based on a Series of Continuous Modes and Even–Odd-Mode Analysis

A method enabling the codesign of a high-efficiency power amplifier (PA) and a ring-resonator microstrip bandpass filter is proposed in this paper. Even-odd-mode analysis and a series of continuous modes (SCMs) are combined to realize broadband or multiband impedance matching as well as the suppression of undesired signals. The proposed codesign method can achieve both broadband and multiband frequency responses, and the designed component is relatively easy to analyze and fabricate due to its microstrip structure. For verification, a broadband and triband PA-filter components are designed and fabricated separately. The first component operates across 0.8-3.2 GHz (120%) with 39.7-42.9-dBm maximum output power and 57%-74% drain efficiency (DE). The second component, which has three passbands, covers several commercial frequencies with a measured output power of 39.6-41.3 dBm and DE from 62% to 68%. When these two components are driven by a 20-MHz long-term evolution signal with a peak-to-average power ratio of 6.2 dB, adjacent channel leakage ratios from -26.4 to -33.8 dBc and from -29.4 to -33.1 dBc are measured, respectively.