Wide band multiple side-lobe canceller

• US 4,586,045 A
• Filed: 10/05/1970
• Issued: 04/29/1986
• Est. Priority Date: 10/05/1970
• Status: Expired due to Term

• Current Assignee: United States Of America As Represented By The Secretary Of The Air Force
• Original Assignee: United States Of America As Represented By The Secretary Of The Air Force
• Inventors: Downie, John W.
• Primary Examiner(s): Tubbesing, T. H.
• Application Number:
  US05/090,196
• Time in Patent Office: 5,685 Days
• Field of Search: 343/18 E, 343/100 LE, 343/379-382
• US Class Current: 342/17
• CPC Class Codes: G01S 7/2813 Means providing a modification of the radiation pattern for cancelling noise, clutter or interfering signals, e.g. side lobe suppression, side lobe blanking, null-steering arrays specially adapted to secondary radar systems G01S13/762; aerials or aerials systems H01Q21/29, H01Q25/00
• CPC Class Codes: G01S 7/36 Means for anti-jamming , e.g. ECCM, i.e. electronic counter-counter measures
• CPC Class Codes: H01Q 3/2635 the auxiliary unit being composed of a plurality of antennas

Abstract

An IF side-lobe canceller having a main channel and a pair of auxiliary channels in which the signal from the main channel is mixed with a stable local oscillator and fed to a subtractor, while in each of the pair of auxiliary channels the signal from an omnidirectional antenna is fed to a mixer and then to the subtractor. The subtractor'"'"'s output is fed to mixers together with the signals from the omnidirectional antennas. The outputs of these mixers are fed to additional mixers together with the mixed outputs of the stable local oscillator and a second oscillator.

Claims

1. An IF side-lobe canceller comprising:

(a) a main channel including,

(1) a radar antenna,

(2) a first local oscillator,

(3) a first main mixer fed by the radar antenna and the first local oscillator,

(4) a subtractor to which the output of the first mixer constitutes one input,

(5) a second local oscillator, and

(6) a second main mixer fed by the first and second local oscillators, and

(b) a plurality of auxiliary channels, each channel including,

(1) an omnidirectional antenna,

(2) a first auxiliary mixer fed by the omnidirectional antenna and the subtractor,

(3) a second auxiliary mixer fed by the first auxiliary mixer and the second main mixer,

(4) a third auxiliary mixer fed by the second auxiliary mixer and the second main mixer, and

(5) a fourth auxiliary mixer fed by the third auxiliary mixer and the omnidirectional antenna, the output of the fourth auxiliary mixer being fed to the subtractor.

2. An IF side-lobe canceller according to claim 1 which further comprises in each auxiliary channel a narrow band filter interposed between the second and third auxiliary mixers.

3. An If side-lobe canceller according to claim 2 which further comprises a duplexer interposed between the radar antenna and the first main mixer.