Accession Number : ADD012355

Title :   Apparatus for the Detection of Angles-of-Arrival of Radio Frequency Signals.

Descriptive Note : Patent Application,

Corporate Author : DEPARTMENT OF THE ARMY WASHINGTON DC

Personal Author(s) : Klose,Dirk R ; Czentirmai,George ; French,Barry T

Report Date : 07 May 1986

Pagination or Media Count : 20

Abstract : Incoming radio frequency signals from one or more remote transmitters, that may be changing or 'hopping' in frequency, are received at two closely spaced antennas. A pair of Chirp-Z transform processors are respectively coupled to said antennas. The transform processors are operated in synchronism and produce a pair of sampled comb filter output responses, each of which comprises a multiple of frequency 'bins' distributed over a given spectrum. The bins are read out of the Chirp-Z processors in a synchronous sequential order, and each bin is represented by a pair of signals in phase quadrature. The phase quadrature signals of corresponding bins are multiplied in a predetermined manner and the products there of are selectively added and subtracted to provide a predetermined function (tan psi) of the phase difference (psi) between the signals incident on the pair of antennas. This predetermined function is coupled to a processor that calculates a trigonometric function (are sine) thereof which is indicative of the angle-of-arrival of the incident wave(s).

Descriptors :   *PATENT APPLICATIONS, *RADIO DIRECTION FINDERS, DETECTION, RADIO SIGNALS, ANTENNAS, SIGNALS, READ OUT TECHNIQUES, RADIOFREQUENCY, RESPONSE, TRIGONOMETRY, SAMPLING, FREQUENCY AGILITY, OUTPUT, FUNCTIONS

Subject Categories : Direction Finding
      Radiofrequency Wave Propagation

Distribution Statement : APPROVED FOR PUBLIC RELEASE