Airborne frequency-modulation radar and its application to a missile homing head
AssigneeThomson-CSF
InventorRemy Tabourier
Life of this patent
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Abstract
In an airborne frequency-modulation radar designed for the homing head of a guided missile, enhanced resolution both in distance and in velocity is obtained by making use of a solid-state transmitter in conjunction with a frequency-modulating oscillator and by means of a receiver comprising a controlled frequency-shift oscillator.
Claims11
An airborne frequency-modulation radar comprising a transmission-reception antenna and a duplexer connected on the one hand with transmission means for delivering a wave which is frequency-modulated by first modulating means and pulse-modulated by second modulating means and on the other hand with reception means including demodulating means, means for sampling, coding and filtering demodulated signals, wherein the form factor of the modulation pulses generated by the second modulating means being much lower than 1/2, the reception means further comprises:
- means for adding the frequency of the output frequency-modulated signal of the first modulating means and the frequency F=f.sub.i +m.tau.+fm of the signal delivered by a voltage-controlled oscillator, wherein m is the slope of the frequency-modulation carried out by the first modulating means, fi a constant predetermined intermediate frequency, .tau. a time-delay (2d/Vc) representing the selected search distance d, Vc being the velocity of the light in the medium considered, f.sub.m is equal to 2 f.sub.0 (V.sub.m cos .theta.+V.sub.k)/Vc, V.sub.m being the velocity of the missile, V.sub.k the radial velocity of the target, f.sub.0 the nominal frequency transmitted and .theta. the angle between the velocity V.sub.m of the missile and the direction of the target;
- and
- means for mixing the echo signal reflected from the target and the signal delivered by the adding means.
An airborne frequency-modulation radar comprising a transmission-reception antenna and a duplexer connected on the one hand to transmission means delivering a wave which is frequency modulated by first modulating means and pulse-modulated by second modulating means and on the other hand to reception means including demodulating means, means for sampling, coding and filtering demodulated signals, wherein the second modulating means generating pulses with a form factor much lower than 1/2, the first modulating means comprises:
- a master oscillator delivering a signal linearly frequency-modulated by a sawtooth voltage;
- a controllable frequency oscillator supplying a frequency divider;
- and
- means for mixing the output signals of the master oscillator and of the frequency divider and supplying the transmission means.
Dependencies are inferred from the claim text.