Direction finding apparatus

• US 5,075,696 A
• Filed: 09/18/1989
• Issued: 12/24/1991
• Est. Priority Date: 10/28/1988
• Status: Expired due to Fees

• Current Assignee: Marconi Holdings Company Limited
• Original Assignee: Marconi Holdings Company Limited
• Inventors: Brett, Anthony R. H., Wilby, William A.
• Primary Examiner(s): Issing, Gregory C.
• Application Number:
  US07/408,666
• Time in Patent Office: 827 Days
• Field of Search: 342/432-434, 342/437, 342/417, 342/444, 342/445
• US Class Current: 342/432
• CPC Class Codes: G01S 3/28 using amplitude comparison of signals derived simultaneously from receiving antennas or antenna systems having differently-oriented directivity characteristics

Abstract

Direction finding apparatus comprising at least ten antenna channels for connection to respective antennae in use, at least five receiver channels each coupled to at least two different antenna channels constituting a group, and circuitry for receiving and comparing the outputs of the receiver channels to determine the angular location of the signal source; the arrangement being such that in use the antennae of each group of antenna channels have a sufficient angular separation such that only one is capable of detecting the signal source at one time, and the nearest neighboring antennae of each group are coupled to respective different receiver channels different from the receiver channel of that group.

Claims

1. Direction finding apparatus for locating a signal source, comprising:

at least ten antenna channels for connection to respective antennas in use, at least five receiver channels having signal outputs, each receiver channel being coupled to at least two different antenna channels constituting a group to provide every pair of adjacent antennas with a different combination of receiver channels, and means for receiving and comparing the signal outputs of all the receiver channels to identify the two highest signal outputs and to determine therefrom the angular location of the signal source, the antennas of each group of antenna channels being sufficiently angularly separated that, at most, one of the antennas of each group is capable of receiving significant signal power from the signal source at one time.

2. Apparatus according to claim 1, further comprising at least ten said antennas coupled to respective said antenna channels.

3. Apparatus according to claim 2, in which the minimum angular separation of the antennas coupled to any one of said receiver channels is three 3 dB beamwidths of the antennas.

4. Apparatus according to claim 2, in which the antenna boresight axes are coplanar.

5. Apparatus according to claim 4, in which the antenna boresight axes coincide at a point.

6. Apparatus according to claim 5, in which the antenna boresight axes are disposed equi-angularly about a central point.

7. Apparatus according to claim 2, in which ten antennas are coupled to five receiver channels and are sequentially and equi-angularly arranged relative to one another;

and wherein a first and a fourth antenna are coupled to a first receiver channel; and

wherein a second and a sixth antenna are coupled to a second receiver channel; and

wherein a third and an eighth antenna are coupled to a third receiver channel; and

wherein a fifth and a ninth antenna are coupled to a fourth receiver channel; and

wherein a seventh and a tenth antenna are coupled to a fifth receiver channel.

8. Apparatus according to claim 2, in which twelve antennas are coupled to six receiver channels and are sequentially and equi-angularly arranged relative to one another;

and wherein a first and a sixth antenna are coupled to a first receiver channel; and

wherein a second and an eighth antenna are coupled to a second receiver channel; and

wherein a third and a tenth antenna are coupled to a third receiver channel; and

wherein a fourth and a twelfth antenna are coupled to a fourth receiver channel; and

wherein a fifth and a ninth antenna are coupled to a fifth receiver channel; and

wherein a seventh and an eleventh antenna are coupled to a sixth receiver channel.

9. Apparatus according to claim 2, in which twenty-one antennas are coupled to seven receiver channels and are sequentially and equi-angularly arranged relative to one another;

and wherein a first, fifth and eighth antenna are coupled to a first receiver channel; and

wherein a twelfth, seventeenth and twenty-first antenna are coupled to a second receiver channel; and

wherein a third, sixth and thirteenth antenna are coupled to a third receiver channel; and

wherein a seventh, tenth and sixteenth antenna are coupled to a fourth receiver channel; and

wherein a ninth, fourteenth and eighteenth antenna are coupled to a fifth receiver channel; and

wherein a fourth, fifteenth and twentieth antenna are coupled to a sixth receiver channel; and

wherein a second, eleventh and nineteenth antenna are coupled to a seventh receiver channel.