Perturbation-based dynamic measurement of antenna impedance in real-time

摘要

Devices and methods are disclosed for real-time calibration of a tunable matching network that matches the dynamic impedance of an antenna in a receiver. Processing logic is operable to solve multiple non-linear equations to determine the reflection coefficient of the antenna. The tunable matching network is repeatedly perturbed and the power received by the antenna is measured after each perturbation at the same node in the matching network. The measured power values are used by an optimizer in converging to a solution that provides the reflection coefficient of the antenna. The reflection coefficient of the antenna may be used to determine the input impedance of the antenna. The elements of the matching circuit may then be adjusted to match the input impedance of the antenna.

主权项

1. A wireless communications system, comprising:
an antenna; a matching circuit coupled to said antenna, said matching circuit having an operating frequency; a control system operable to calculate, in real-time, a value for an input impedance of the antenna, wherein said input impedance is calculated based on a first received power measurement corresponding to said matching circuit tuned at said operating frequency, a second received power measurement corresponding to said matching circuit tuned at a first perturbed frequency equal to the operating frequency minus a frequency perturbation step interval, and a third received power measurement corresponding to said matching circuit tuned at a second perturbed frequency equal to the operating frequency plus the frequency perturbation step interval.