Model-Referenced Tuning Algorithm for L-Network Impedance Tuner of Long-Wave Antenna

Imprecise impedance matching between transmission line and long-wave antenna will cause damage to the front-end transmitter. The existing tuning algorithms have the disadvantages of low tuning accuracy and slow search speed in the strong electromagnetic interference working environment of long-wave communication. To realize accurate and fast longwave antenna tuning, this paper proposes a model-referenced tuning algorithm for L-network impedance tuner. The proposed algorithm divides the tuning process into three stages: initial value calculation, adjustment-value-calculation-based coarse tuning and fine tuning. In the “adjustment-value-calculation-based coarse tuning” stage, the adjustment values of the tuning elements are calculated quantitatively referring to the impedance matching network model. Compared with the conventional functional tuning algorithm, the proposed algorithm has higher tuning accuracy and faster search speed. The performance of the proposed algorithm is verified by the simulation.