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. 29, 1997
Filed:
Mar. 10, 1995
Paul K Tom, Saratoga, CA (US);
Valentine L Denninger, Sunnyvale, CA (US);
Trimble Navigation Limited, Sunnyvale, CA (US);
Abstract
An antenna system for a navigation satellite receiver tuned to dual-frequency transmissions from orbiting navigation satellites. Respective L1 and L2 microwave patch antennas are mounted flat and adjacent to one another on a common ceramic substrate and have their centers grounded to a groundplane on the opposite side of the substrate with vias. Each patch antenna is connected to a respective near-by low-noise amplifier. The low-noise amplifiers are both connected to a signal combiner and a final radio frequency amplifier for down feed to a navigation satellite receiver. A direct current signal from the navigation satellite receiver is used on the down-feed to selectively control which one of the two low-noise amplifiers is to operate. Thus one coaxial down-feed supplies power to the low-noise amplifiers and provides for the selection between the L1 and L2 carrier frequencies on the down-feed.