Research/Patents/US 4652864
US 4652864

MICROWAVE PROXIMITY SENSOR

Assignee

Filed

Jul 26, 1982

Granted

Mar 24, 1987

Location

PORTOLA VALLEY CA US

Abstract

Microwave oscillator means wherein the resonant frequency determining element is a 1/2 or 1/4-wavelength folded dipole antenna that also serves as the transmitting and receiving antenna, capacitor means that is alternately charged and then discharged through said oscillator means until the voltage drops so low that oscillation ceases at which point the capacitor is charged again, negative peak follower means to convert the minimum voltage across the capacitor into a DC voltage, and comparator means to detect changes in the output voltage of the peak follower caused by the approach of a person or object to the 1/2 or 1/4-wavelength antenna.

Source: Google Patents

35 USC §181 Secrecy Order

Imposed

Nov 29, 1982

Rescinded

Nov 14, 1985

Duration

2 years, 11 months

Inventor

  • 1NOEL M. CALVIN

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Back to patent indexSource: USPTO 35 USC §181 secrecy order records