Multiple intermediate frequency side-lobe canceller

• US 4,044,359 A
• Filed: 01/09/1962
• Issued: 08/23/1977
• Est. Priority Date: 01/09/1962
• Status: Expired due to Term

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: General Electric Company
• Inventors: Applebaum, Sidney P., Kovarik, James C., Howells, Paul W.
• Primary Examiner(s): Wilbur, Maynard R.
• Assistant Examiner(s): Berger, Richard E.
• Application Number:
  US04/165,259
• Time in Patent Office: 5,705 Days
• Field of Search: 343/100.7, 343/18, 343/5, 343/100, 343/100.12, 343/18 E, 325/473-477, 325/301-307, 325/365-367, 325/371
• US Class Current: 342/379
• CPC Class Codes: G01S 3/06 Means for increasing effective directivity, e.g. by combining signals having differently oriented directivity characteristics or by sharpening the envelope waveform of the signal derived from a rotating or oscillating beam antenna comparing amplitude of signals having differently oriented directivity characteristics to determine direction G01S3/16, G01S3/28
• 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: H01Q 3/2635 the auxiliary unit being composed of a plurality of antennas
• CPC Class Codes: H04K 2203/32 including a particular configuration of antennas
• CPC Class Codes: H04K 3/228 Elimination in the received signal of jamming or of data corrupted by jamming interference suppression in receivers H04B1/10

Abstract

1. In an undesired signal canceller, a main signal transmission channel having an output terminal, a plurality of auxiliary signal transmission channels having output terminals, means for cross coupling each of said auxiliary channels separately to said main signal transmission channel, means for generating error signals representing the relative amplitude and phase of each undesired signal in the auxiliary channels cross-coupled with undesired signals in the main channel, compensating cross feed networks capable of adjustment for minimizing cross coupling at said main channel output terminal, and means responsive to said error signals for adjusting said cross feed networks in order to minimize cross coupling.

Claims

1. In an undesired canceller, a main signal transmission channel having an output terminal, a plurality of auxiliary signal transmission channels having output terminals, means for cross coupling each of said auxiliary channels separately to said main signal transmission channel, means for generating error signals representing the relative amplitude and phase of each undersired signal in the auxiliary channels cross-coupled with undesired signals in the main channel, compensating cross feed networks capable of adjustment for minimizing cross coupling at said main channel output terminal, and means responsive to said error signals for adjusting said cross feed networks in order to minimize cross coupling.

2. In an intermediate frequency multiple sidelobe canceller, a main signal transmission channel having a directional antenna adapted to receive desired signals, a plurality of auxiliary signal transmission channels having omni-directional antennas adapted to receive primarily undesired signals, means coupling said directional antenna thru a conventional mixer to produce an intermediate frequency signal and thru a signal combining circuit to an output terminal, means coupling said omni-directional antennas thru conventional mixers to produce intermediate frequency signals and to one input of each of a plurality of band pass cross correlators, means coupling said output terminal to another input of each of said cross correlators, said cross correlators having output signals representative of the amplitude and phase difference of the components of said undesired signal in each of said channels, means for heterodyning said cross correlator output signals with said intermediate frequency signals of said auxiliary channels to produce auxiliary channel outputs at the same frequency as the intermediate frequency in said main channel and with any phase differences removed, and means coupling said auxiliary channel outputs to said combining circuit in order to subtract them from the signal in said main channel.

3. In combination, a main signal transmission channel having an output terminal and an input terminal adapted to receive a desired signal and a plurality of undesired signals, a plurality of auxiliary signal transmission channels adapted primarily to receive said undesired signals, a plurality of means for combining each of the auxiliary channel undesired signals with said first channel signals to provide a plurality of first signals, a plurality of means for mixing each of the undersired auxiliary channel signals with a related one of said first signals to provide a plurality of second signals, means for substantially modifying the undesired signals available at said output terminal comprising means responsive to the amplitudes and phases of said second signals for controlling the amplitude and phase of each of said undesired signals.

4. In combination, a main signal transmission channel capable of receiving a desired signal and a plurality of undesired signals and having an output terminal, a plurality of auxiliary signal transmission channels adapted primarily to receive said undesired signals, correlating means for comparing the portions of said undesired signals present in said main and auxiliary channels to determine their phase and amplitude relationship, means for mixing the output of said correlating means with said undesired signals in said individual auxiliary channels to provide compensating signals, means for subtracting said compensating signals from the signals present in said main channel for minimizing the amount of said undesired signals at said output terminal.

5. In an intermediate frequency sidelobe canceller, a main signal transmission channel having a directional antenna adapted to receive desired signals, a plurality of auxiliary signal transmission channels having a plurality of omni-directional antennas arranged in a linear array and adapted to receive primarily undesired signals, means coupling said directional antenna in series thru a mixer to produce a first intermediate frequency signal and thru a signal combining circuit to an output terminal, means coupling each of said omni-directional antennas thru a separate mixer to produce an intermediate frequency signal, means connecting each of the outputs of the separate mixers associated with said omni-directional antennas to one input of one of a plurality of cross correlators, means coupling said output terminal to another input of each of said cross correlators, said cross correlators generating output signals representative of the amplitude and phase differences of the components of said undesired signals present at the outputs of each of said mixers, means for heterodyning each of said cross correlator output signals with the intermediate frequency signal from each of said auxiliary channels to produce auxiliary channel outputs having components at the same frequencies as the intermediate frequencies of the signal components in the main channel and with any phase differences removed, and means coupling said auxiliary channel outputs to said combining circuit in order to substract the signal components having intermediate frequencies the same as those present in the main channel from the signals in said main channel.

6. In combination, a main signal transmission channel having a directional antenna capable of receiving desired and undesired signals and having an output terminal, a plurality of auxiliary signal transmission channels each coupled to an omni-directional antenna primarily to receive said undesired signals, a plurality of correlating means for comparing the portions of each of said undesired signals present in said main channel and each of the corresponding undesired signals in said auxiliary channels to determine their phase and amplitude relationship, means for heterodyning the outputs of each of said correlating means with the undesired signals in each auxiliary channel to provide compensating signals, means for subtracting the frequency components of said compensating signals having frequency counterparts in said main channel from the signals present in said main channel for minimizing the amount of said undesired signals at said output terminal.

7. In an intermediate frequency sidelobe canceller, a main signal transmission channel having an output terminal and an input terminal coupled to receive a desired signal and undesired signals, a plurality of auxiliary signal transmission channels having output terminals and input terminals coupled to receive predominantly said undesired signals, a plurality of cross correlation means each of which is coupled to the output terminal of said main channel and to a separate one of the output terminals of said auxiliary channels, said cross correlation means detecting the relative amplitudes and phases of said undesired signals in said main channel and said undesired signals in said auxiliary channels and providing control signals accordingly, a plurality of cross feed networks coupled to separate output terminals of the auxiliary channels to receive said undesired signals and to said cross correlation means to receive said control signals, said cross feed networks including means automatically responsive to said control signals to adjust the amplitude and phase of each of said undesired signals to provide correcting signals equal in amplitude and phase to each of the undesired signals appearing at the output terminal of said main channel, and means for substracting said correcting signals from said desired signal distorted by undesired signals to provide a pure signal.

8. In an intermediate frequency sidelobe canceller, a main signal transmission channel having an output terminal and an input terminal coupled to receive a signal distributed by noise from a plurality of sources, a plurality of auxiliary signal transmission channels having output terminals and input terminals coupled to receive predominantly said noise from a plurality of sources, a plurality of cross correlation means each of which is coupled to the output terminal of said main channel and to a separate one of the output terminals of said auxiliary channels, said cross correlation means detecting the relative amplitudes and phases of said noise in said main channel and said noise in said auxiliary channels and providing control signals accordingly, a plurality of cross feed networks coupled to separate output terminals of the auxiliary channels to receive said noise and to said cross correlation means to receive said control signals, said cross feed networks including means automatically responsive to said control signals to adjust the amplitude and phase of said noise in each auxiliary channel to provide correcting signals equal in amplitude and phase for subtracting said correcting signals from said desired signal distorted by noise to provide a pure signal.