James D Proctor

US Patent:

20020079845, Jun 27, 2002

Filed:

Feb 6, 2001

Appl. No.:

09/776698

Inventors:

Douglas Kirkpatrick - Great Falls VA, US
Gary Bass - Mt.Airy MD, US
Jesse Copsey - Germantown MD, US
Lauren Dymond - North Potomac MD, US
William Garber - Poolesville MD, US
Aleksandr Gitsevich - Montgomery Village MD, US
William Grimm - Silver Spring MD, US
Vincent Kwong - Vancouver, CA
Izrail Levin - Silver Spring MD, US
Donald MacLennan - Gaithersburg MD, US
Samuel Ola - Forest VA, US
James Proctor - Monrovia MD, US
Robert Roy - Frederick MD, US
James Simpson - Gaithersburg MD, US
Paul Steiner - Olney MD, US
Peter Tsai - Olney MD, US
Brian Turner - Damascus MD, US

International Classification:

H05B041/16

US Classification:

315/248000, 315/246000, 315/005000

Abstract:

An ultra bright, low wattage inductively coupled electrodeless aperture lamp is powered by a solid state RF source in the range of several tens to several hundreds of watts at various frequencies in the range of 400 to 900 MHz. Numerous novel lamp circuits and components are disclosed including a wedding ring shaped coil having one axial and one radial lead, a high accuracy capacitor stack, a high thermal conductivity aperture cup and various other aperture bulb configurations, a coaxial capacitor arrangement, and an integrated coil and capacitor assembly. Numerous novel RF circuits are also disclosed including a high power oscillator circuit with reduced complexity resonant pole configuration, parallel RF power FET transistors with soft gate switching, a continuously variable frequency tuning circuit, a six port directional coupler, an impedance switching RF source, and an RF source with controlled frequency-load characteristics. Numerous novel RF control methods are disclosed including controlled adjustment of the operating frequency to find a resonant frequency and reduce reflected RF power, controlled switching of an impedance switched lamp system, active power control and active gate bias control.