Utilizing Distributed Circuit Topology Techniques to Achieve Greater Power Handling for High Power Impedance Matching RF Applications

With many midband spectrum reallocations for fifth-generation (5G) wireless communications causing a congested spectrum, flexibility in high-power transmitter system operating frequency is needed while maintaining transmission range. Reconfigurable impedance tuners can provide versatile power-amplifier load matching as operating frequency changes to maintain maximum transmission range. A reconfigurable impedance tuner for a high-power transmitter should possess minimal loss, broad Smith Chart coverage, fast reconfigurability, and high-power handling. A periodic capacitor-loaded, distributed, switched-network topology can gradually match the input to the output, reducing spatial voltage and current variations. The reduced variations result in lower maximum branch currents providing higher power handling while maintaining Smith Chart coverage, tuner loss, and real-time switching speeds. This technique is applied for the first time, to our knowledge, toward increasing the power handling of reconfigurable matching networks. Reconfiguration to maintain performance will enable frequency agility in systems with high-power transmitters, such as radars, long-distance communications, and point-to-point communications, enabling spectral coexistence capabilities. A measurement-validated EM simulation demonstrates that a realizable, distributed-circuit impedance tuner, operating from 1 to 2 GHz, achieves at least a 2.1 times increase in worst-case power handling over all frequencies and states compared to a lumped circuit (nondistributed) impedance tuner. This 2.1 times improvement is achieved with similar Smith Chart coverage, only a 9.9% increase in average tuner loss when using a rather lossy switch, a flatter loss response over frequency, and a 34.8% reduction in maximum branch currents. The distributed circuit technique will enable real-time impedance tuners to be integrated with high-power cognitive transmitter systems, enabling maximum transmission range while providing frequency agility in the congested spectrum.