CA2777064A1

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.

CA2777064A1, drawing sheet 1
Sheet 1 of 12

Term

4.1 yearsto projected expiry

Projected expiry 14 October 2030, counted from filing; an application has no term until it is granted.

  1. Priority
  2. Filed
  3. Published
  4. Today
  5. Projected expiry

14 claims: 1 independent, 13 dependent

  1. 1
    CA 02777064 2012-04-05 CLAIMS What is claimed is:1. A wireless communications system, comprising: an antenna;a control system that calculates, in real-time, a value of an input impedance of the antenna to match a load in a receiver system;and a matching network that is tunable by the control system to match the calculated values of the input impedance of the antenna to a load on the receiver system.
  2. 13
    14. The wireless communications system of claim 13, a first non-linear equation of the two non-linear equations is expressed as:„(1) k (1) | 2 |i ς (0) Γ | 2 |i r γ (0) | 2 py _ | 5 22| | 1 ~ 5 22 γ ι-| II P ( , o) |ς(°’| 2 |ι ç«r I 2 |i r r (1 J 2 ’ L | S 21| ( 1 -- y 22 r i| p-GlPinl wherein is the ratio of power received by the load at a first tuning p L position of the reactive elements of the matching network;S^is a scattering matrix parameter that represents an output reflection coefficient of a 50 ohm terminated input after a first perturbation of the matching network;S® is a matrix parameter that represents an output reflection coefficient of a 50 ohm terminated input in a previous tuning period;S® is a scattering matrix parameter which represents the forward transmission coefficient of a 50 ohm terminated output in a previous tuning period;r L is a reflection coefficient of the load, and Γ is an input reflection coefficient of the matching network as seen from the antenna in a previous tuning period;Γ is an input reflection coefficient of the matching network as seen from the antenna after a Docket No. 36250-WO-PCT Page 37 of 39 CA 02777064 2012-04-05 first perturbation of the matching network;and Γ Α is the reflection coefficient of the antenna.