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:
Jun. 17, 1980
Filed:
Nov. 01, 1978
Roland Allezard, Verrieres le Buisson, FR;
U.S. Philips Corporation, New York, NY (US);
Abstract
This detection system of the radar type transmits a sawtooth-shaped frequency-modulated centimeter wave. The wave reflected by an obstacle, if any, is received by two fixed receiving antennas, each of these receiving antennas being connected to a circuit for processing the received signal. The phase shift between the waves is a measure for the angle .theta. formed between the path of flight of the aircraft and the straight line which connects the aircraft with the obstacle. Said phase shift is analyzed in an output circuit of the detection device which also comprises a control loop for controlling the amplitude of the beat-frequency signal between the transmitted signal and the received signal, a synthesizing circuit for a signal fan creating a range window by demodulation of the beat-frequency signal by means of the synthesized signal, a Doppler effect tracking loop and a circuit for analyzing the leading edge of the Doppler effect in the demodulated and filtered signal. In the case of an obstacle which is substantially directly in the direction of flight, last-mentioned circuit produces an information which possibly evaluates the information with respect to the angle .theta. and which is already present in the output circuit, in response whereto an alarm circuit becomes operative.