Dual-frequency microwave radio antenna system
Patent 5625365 Issued on April 29, 1997. Estimated Expiration Date: 
March 10, 2015. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
March 10, 2015. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesMicrowave antenna structure Directional scanning circular phased array antenna Floating antenna system Patent #: 5406294 InventorsAssigneeApplicationNo. 402194 filed on 03/10/1995US Classes:343/700MS, Microstrip343/701, Having electric space discharge device343/872With housing or protective coveringExaminersPrimary: Le, HoanganhAttorney, Agent or FirmForeign Patent References
International ClassesH01Q 001/38H01Q 001/42 AbstractAn 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. | |
