CA2777064C

Dynamic real-time calibration for antenna matching in a radio frequency receiver system

Abstract

Real-time calibration of a tunable matching network that matches the dynamic impedance of an antenna in a radio frequency receiver system. The radio frequency receiver system includes two non-linear equations that may be solved 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 are then adjusted to match the input impedance of the antenna.

CA2777064C, drawing sheet 1
Sheet 1 of 12

Term

4.1 yearsleft in the term

Expires 14 October 2030.

  1. Priority
  2. Filed
  3. Granted
  4. Today
  5. Expires

20 claims: 3 independent, 17 dependent

  1. 1
    CA 02777064 2014-05-13 Claims:1. A wireless communications system, comprising: a tunable matching network having an input and an output, the output of the tunable matching network connected via a low noise amplifier to an input of a power detector, an output of the power detector connected to a radio frequency receiver in a receiver system;an antenna connected at the antenna feedpoint to the input of the tunable matching network to input electromagnetic signals from the antenna to the radio frequency receiver;a control system configured to use three different measurements of power levels detected at a single location by the power detector to calculate, in real-time, a complex value of an input impedance of the antenna at the antenna feedpoint, by using the three different power measurements simultaneously to solve two non-linear equations, and to tune the matching network to match its input impedance to the calculated value of the input impedance of the antenna.
  2. 14
    A network server comprising a computer recordable storage medium tangibly embodying computer executable program code, which when executed by a controller, performs actions comprising:solving, with a non-linear optimizer, for a reflection coefficient of an antenna in a receiver by calculating a solution to two non-linear equations wherein the calculation uses three different power measurements simultaneously, where the three different power measurements of power level were detected at a single location by a power detector;converting, through the controller, the reflection coefficient to a value of an input impedance of the antenna;and tuning a number of reactive elements of a matching network to values that match the input impedance wherein the reactive elements are a tunable matching network having an input and an output, the output of the tunable matching network connected via a low noise amplifier to an input of the power detector, an output of the power detector connected to the receiver.
  3. 17
    A computer implemented method of matching the impedance of an antenna in a receiver, the computer implemented method comprising:solving with a non-linear optimizer, for a reflection coefficient of an antenna, Ta, by calculating simultaneously a solution to two non-linear equations, wherein the calculation uses three different power measurements, where the three different power measurements of power level were detected at a single location by a power detector;converting, through a controller, the reflection coefficient to a complex value of an input impedance of the antenna;and tuning a number of reactive elements of a matching network to values that match the input impedance wherein the reactive elements are a tunable matching network having an input and an output, the output of the tunable matching network connected via a low noise amplifier to an input of a power detector, an output of the power detector connected to the receiver.