Tracking radar receiver
AssigneeGeneral Dynamics Decision Systems, Inc.
InventorChester D. Shupe
Life of this patent
Estimating the term…
Abstract
A tracking radar receiver as described herein is relatively invulnerable to image frequency jamming. Partial image-rejection down-converters down-convert RF signals to IF signals in each of various sum and difference receiver channels. Image frequency components of the IF signals exhibit a predetermined amplitude and phase relationship relative to corresponding real frequency components for each of the channels. Thus, phase and amplitude tracking between the various channels is achieved even when image frequency signals are received.
Claims12
A receiver for a tracking radar, said receiver comprising:
- an antenna having a plurality of elements;
- a combination hybrid having a plurality of inputs each of which is coupled to a, unique one of said plurality of elements of said antenna and having sum and difference outputs;
- a first partial image-rejection down-converter coupled to the sum output of said combination hybrid;
- a second partial image-rejection down-converter coupled to the difference output of said combination hybrid;
- and
- a demodulator having a first input coupled to the output of said first down-converter and a second input coupled to the output of said down-converter, said demodulator being for providing an error output signal.
A method of processing signal in a tracking radar, said method comprising the steps of:
- receiving, at a plurality of antenna elements, a radio frequency signal;
- combining signals from the antenna elements of said receiving step to produce a sum signal and a difference signal;
- imbalancing image frequency components of the sum signal from said combining step in a first partial image-rejection down-converter that produces a first IF signal so that an image ratio of the first down-converter is between 10 db and 16 db;
- imbalancing image frequency components of the difference signal from said combining step in a second partial image-rejection down-converter that produces a second IF signal so that an image ratio of the second down-converter is between 10 db and 16 db;
- and
- demodulating the first and second IF signals to produce an error signal.
Dependencies are inferred from the claim text.