Patent ID: 8536982

Claim:
A reader for reading a memory tag, the reader comprising: a resonant circuit component having a resonant frequency and comprising at least a first variable capacitive element and a second variable capacitive element; a frequency source operable to generate a driving signal and coupled to the resonant circuit component to provide inductive coupling to the memory tag; a tuning detector configured to generate a tuning signal responsive to relative resonant frequencies of the resonant circuit component and a resonant circuit component of the memory tag; and a tuning controller, responsive to the tuning signal, to control the resonant frequency of the resonant circuit component, the tuning controller being configured to perform a tuning operation of the resonant circuit component by: (i) changing a value of the first variable capacitive element while detecting an error signal provided by the resonant circuit component a first predetermined number of times, (ii) then changing a value of the second variable capacitive element while detecting the error signal a second predetermined number of times, each of the first and second predetermined numbers being greater than zero, and (iii) repeating (i) and (ii) until the error signal is determined to be less than a threshold error amount or until a time out limit has been reached.