A novel RF tunable impedance matching network for correcting the tested result deviation from simulated result

In practical situation of designing a power amplifier, inaccurate model, tolerance of the components, manufacture tolerance, variation in substrate dielectric could make the measurement result different from simulated result. For correcting those errors, a novel tunable matching network with simple structure in load matching network is presented in this paper. Two variable capacitors are integrated in the load as a part of the matching network. The output impedance could be modified by changing the values of these two capacitors. By this method, 8 impedance points around the original simulated maximum PAE (Power added efficiency) point are chosen and measured to get the maximum PAE. A class B power amplifier at one-tone frequency 2.14 GHz with this structure is designed, fabricated and tested for demonstrating the method of correcting. The measurement result before correcting is different from the simulated one. After tuning these two capacitors in load matching network, the PAE is increased by 21.8% from 33.4% to 55.2%, which more agrees with the simulated results.