The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 04, 2000
Filed:
Jul. 22, 1998
Yogendra K Chawla, Pittsford, NY (US);
Craig A Covert, Rochester, NY (US);
ENI Technologies, Inc., Rochester, NY (US);
Abstract
A high power grounded-drain source follower RF amplifier circuit employs a high voltage MOSFET. The RF signal at the input is applied with respect to ground via an isolation transformer whose secondary feeds the signal between gate and source. The output is taken from the source with respect to drain, which is grounded. A 13.56 MHz 3 KW power amplifier topology with isolated RF input drive for each MOSFET die uses a pair of kilowatt power transistors or KPTs, in which there are multiple large area MOSFET dies, with the drain regions of the dies being formed over a major portion of the die lower surface. The drain regions are in direct electrical and thermal contact with the conductive copper flange. The source and gate regions are formed on the dies away from the flat lower surface. One or more pairs of multi-chip KPTs can be configured to design stable 2.5 KW, 5 KW and 10 KW RF plasma generators at 13.56 MHz. The generators employ a low pass/high pass filter arrangement (diplexer) at the output for low harmonic distortion and dissipative harmonic termination. The terminated high pass filter reduces the gate-to-source differential RF voltage and protects the MOSFETS from damage.