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:
Jul. 04, 1989
Filed:
Apr. 07, 1988
James L Carr, Landover, MD (US);
Marvin S Maxwell, Silver Spring, MD (US);
Other;
Abstract
A direction finding method and apparatus utilizes two receiving antennas which are disposed on a baseline that is rotated around its midpoint at a constant angular velocity. Signals received from a transmitter by the antennas are processed by circuitry that includes a balanced mixer. The balanced mixer multiplies the signals from the two antennas, which are time varying and of different phase due to their rotation and spacing. The output from the balanced mixer is a signal which includes a high frequency component, and a low frequency component. The high frequency component can be used to determine incoming signal amplitude and frequency. The low frequency component can be used to determine the azimuth and elevation angles of the transmitter relative to the plane of rotation of the receiver through analysis of the signal at a number of different times.