US Patent No. 10,893,583

APPARATUS AND METHODS FOR DEFROSTING OPERATIONS IN AN RF HEATING SYSTEM


Patent No. 10,893,583
Issue Date January 12, 2021
Title Apparatus And Methods For Defrosting Operations In An Rf Heating System
Inventorship Lionel Mongin, Chandler, AZ (US)
David Paul Lester, Phoenix, AZ (US)
James Eric Scott, Gilbert, AZ (US)
Assignee NXP USA, Inc., Austin, TX (US)

Claim of US Patent No. 10,893,583

1. A method, comprising:providing, by a radio frequency (RF) signal source, an RF signal through a transmission path to an electrode that is proximate to a cavity of a defrosting system;
repeatedly determining a forward RF power measurement and a reflected RF power measurement along the transmission path and calculating a ratio between the reflected RF power measurement and the forward RF power measurement;
while providing the RF signal and repeatedly determining the forward RF power measurement and the reflected RF power measurement, repeatedly reconfiguring a variable impedance matching network coupled along the transmission path in order to reduce the ratio by improving impedance matching between the RF signal source and the cavity plus a load in the cavity;
while repeatedly reconfiguring the variable impedance matching network, repeatedly determining a frequency at which the variable impedance matching network is reconfigured to improve matching between the RF signal source and the cavity plus the load;
determining, that the frequency at which the variable impedance matching network is reconfigured has dropped below a threshold; and
at a point in time when the frequency at which the variable impedance matching network is reconfigured has dropped below the threshold:
determining an additional time duration for provision of the RF signal to the electrode to achieve a desired state of a load in the cavity of the defrosting system,
continuing to provide the RF signal to the electrode for the additional time duration beyond the point in time, and
ceasing provision of the RF signal to the electrode when the additional time duration has expired.