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:
Aug. 27, 1991
Filed:
Feb. 12, 1990
William S Dipoala, Fairport, NY (US);
Daniel F Pedtke, Fairport, NY (US);
Detection Systems, Inc., Fairport, NY (US);
Abstract
An autodyne microwave motion-detection system includes a supervisory circuit for monitoring the operating status of the microwave energy-producing component of the system. According to a preferred embodiment, the supervisory circuit of the invention comprises a relatively low-cost, 'general purpose UHF' diode, i.e. a multipurpose diode commonly used in circuits designed to accommodate UHF frequencies of up to only about 3 Gigahertz. The supervisory diode is positioned within, or in close proximity to, the resonant cavity of the microwave energy-producing element, the latter being designed to produce microwave energy at a substantially higher frequency (e.g., 10.5 Gigahertz). Due to its close proximity to the microwave energy-producing element (e.g. a Gunn diode) and its presence within the energy field produced thereby, the supervisory diode develops a small, but readily detectable, voltage whenever such element is radiating microwave energy. A voltage-sensing circuit is provided for sensing the instantaneous voltage across the supervisory diode, and the absence of a detectable voltage indicates that the microwave energy-producing element is not functional. Alternatively, the supervisory diode is replaced by an operational amplifier having a capacitor connected across its input leads, and the voltage induced on such input leads by the microwave field is detected to determine the operating status of the microwave transmitter.