Radar apparatus
AssigneeHollandse Signaalapparaten B.V.
InventorsAlbert Groenenboom, Bernard J. Reits
Life of this patent
Estimating the term…
Abstract
Radar apparatus provided with a transmit generator and antenna means for the transmission of comparatively long, linearly frequency-modulated transmitter pulses. Echo signals are received by antenna means and a heterodyne signal is generated in mixer stage. Propagation time differences for different echo pulses are compensated by means of a dispersive delay element incorporated in the radar receiver. Distortion of the echo pulses in the dispersive delay element is corrected on the basis of a Fresnel ripple correction. A Fourier transformation unit transfers the corrected echo pulses to time domain video with low sidelobes.
Claims22
A radar apparatus comprising:
- a transmitter means for generating a transmitter pulse modulated at a predetermined frequency sweep rate and a reference signal modulated at the predetermined frequency sweep rate;
- an antenna means for radiating the generated transmitter pulse and reference signal and for receiving reflected transmitter pulse and reference signals;
- a receiver means comprising a mixer stage for receiving the reflected transmitter pulse and reference signals from the antenna means and for generating a heterodyne signal from the received reflected transmitter pulse and reference signals;
- a dispersive delay element for receiving the heterodyne signal from the receiver means and for frequency-dependent delaying the heterodyne signal;
- and
- a Fourier transformation means comprising:
- a correction means having a weighting means for transforming the delayed heterodyne signal output by the dispersive delay element for correcting distortion of the delayed heterodyne signal to generate a corrected heterodyne signal;
- and
- Fourier transforming means for Fourier transforming the corrected heterodyne signal.
A radar apparatus comprising:
- a transmitter for generating a transmitter pulse and a reference signal modulated at a same predetermined frequency sweep rate;
- an antenna for radiating the generated transmitter pulse and reference signal and for receiving reflected transmitter pulse and reference signals;
- a receiver comprising a mixer for receiving the reflected transmitter pulse and reference signals from the antenna and for generating a heterodyne signal from the received reflected transmitter pulse and reference signals;
- a dispersive delay element for receiving the heterodyne signal from the receiver and for frequency-dependent delaying the heterodyne signal;
- and
- a Fourier transformation circuit comprising:
- a correction circuit having a weighting means for transforming the delayed heterodyne signal output by the dispersive delay element for correcting distortion of the delayed heterodyne signal to generate a corrected heterodyne signal;
- and
- Fourier transforming means for Fourier transforming the corrected heterodyne signal.
Dependencies are inferred from the claim text.