Radio frequency signal direction finding systems
First Claim
1. A radio frequency signal direction finding system comprising:
- (a) a multi-beam antenna having a plurality of feed ports, each one in such feed ports receiving radio frequency energy from a received radio frequency signal, the levels of such energy received at the feed ports being associated with the angle of arrival of the received signal;
(b) receiver means, coupled to the plurality of feed ports, for producing a plurality of output signals, each one of the plurality of output signals having a level related to the level of radio frequency energy received at a corresponding one of the plurality of feed ports;
(c) a plurality of high pass filter means, each one fed by a corresponding one of the output signals produced by the receiver means, for differentiating the output signal fed thereto producing a pulse in response to, and having a level related to, a change in level of the output signal fed thereto; and
,(d) means, responsive to the pulse produced by each one of the plurality of high pass filter means, for determining the angle of arrival of the received signal in accordance with the relative levels of pulses produced by each one of the plurality of high pass filter means.
0 Assignments
0 Petitions
Accused Products
Abstract
A radio frequency signal direction finding system including a multi-beam antenna having a plurality of feed ports, each one of such feed ports receiving energy from the received signals, the levels of such energy being associated with the angles of arrival of such received signals. A plurality of high pass filters or differentiator circuits are coupled to the feed ports for producing output signals related to the changes in levels of the energy received at the feed ports. The output signals are used to determine the angles of arrival of the received signal. Because the angle of arrival of a received signal is determined by output signals representative of the changes in level of the signals received at the feed ports, the angle of arrival of a weaker received signal may be determined even if such weaker signal is received during a time period when a first, stronger, ongoing signal is being received from a different direction.
9 Citations
6 Claims
-
1. A radio frequency signal direction finding system comprising:
-
(a) a multi-beam antenna having a plurality of feed ports, each one in such feed ports receiving radio frequency energy from a received radio frequency signal, the levels of such energy received at the feed ports being associated with the angle of arrival of the received signal; (b) receiver means, coupled to the plurality of feed ports, for producing a plurality of output signals, each one of the plurality of output signals having a level related to the level of radio frequency energy received at a corresponding one of the plurality of feed ports; (c) a plurality of high pass filter means, each one fed by a corresponding one of the output signals produced by the receiver means, for differentiating the output signal fed thereto producing a pulse in response to, and having a level related to, a change in level of the output signal fed thereto; and
,(d) means, responsive to the pulse produced by each one of the plurality of high pass filter means, for determining the angle of arrival of the received signal in accordance with the relative levels of pulses produced by each one of the plurality of high pass filter means. - View Dependent Claims (2, 3, 4)
-
-
5. A radio frequency signal direction finding system comprising:
-
(a) a multibeam antenna having a plurality of feed ports, each one of such feed ports receiving energy from a received radio frequency signal, the levels of the energy received at the feed ports being associated with the angle of arrival of the received signal; (b) receiver means, coupled to the plurality of feed ports, for producing a plurality of output signals, each one of the plurality of output signals having a level related to the level of radio frequency energy received at a corresponding one of the plurality of feed ports; (c) a plurality of high pass filter means, each one fed by a corresponding one of the output signals produced by the receiver means, for differentiating the output signal fed thereto producing a pulse in response to, and having a level related to, a change in level of the output signal fed thereto; and
,(d) means, responsive to the pulse produced by each one of the plurality of high pass filter means, for determining the angle of arrival of the received signal in accordance with the relative levels of pulses produced by each one of the plurality of high pass filter means. - View Dependent Claims (6)
-
Specification