US Patent No. 10,893,581

HEATING OF OBJECTS BY MICROWAVE ENERGY


Patent No. 10,893,581
Issue Date January 12, 2021
Title Heating Of Objects By Microwave Energy
Inventorship Zalman Ibragimov, Rehovot (IL)
Assignee GOJI LIMITED, Hamilton (BM)

Claim of US Patent No. 10,893,581

1. A heating apparatus for heating an object, the apparatus comprising an enclosure for accepting the object adjacent to a radiating plate for heating and a microwave power source coupled to the radiating plate and configured to feed the radiating plate at one or more microwave frequencies, wherein:the radiating plate is an object heating radiating plate configured to heat the object with feed signals having a range of microwave working frequencies of between 300 MHz and 3 GHz, and the radiating plate comprises:
a ground plate; and
at least one or more radiating elements spaced from the ground plate by a dielectric layer,
wherein at least a size and a shape of the one or more radiating elements and at least a thickness of the dielectric layer satisfy the following conditions:
a free space efficiency of the radiating plate is less than ?6 dB and a contact efficiency of the radiating plate is greater than 50%,
the free space efficiency is a ratio of power not returned from the radiating plate to power fed to the radiating plate at a test frequency in the range of working frequencies in a free space condition in which there is a volume of free space covering the radiating plate,
the contact efficiency is a ratio of power not returned from the radiating plate when a test load rests on top of the radiating plate to power fed to the radiating plate at the test frequency, and
the test load has a dielectric constant in the range of 20 to 60 and a loss tangent in the range of 0.1 to 0.5 at the test frequency,
wherein said conditions are configured to provide a first amount of energy transfer from the radiating plate to the test load with the radiating plate being in contact with the test load while providing a second amount of energy transfer, smaller than the first amount, with the radiating plate not being in contact with the test load.