The Marconi Company Limited

Bae Systems Electronics Limited

Michael A Jones

John T Floyd

John R Woods

Christopher D Huggett

Anthony J Benson

John W Attwood

David W Joynson

Oliver H Walter

Alan J Mitchell

Frederick L Pew

John A Gurr

Geoffrey Warman

Richard H Campbell

Peter Szyszko

A dual mode radar seeker comprising a wide-band passive anti-radar antenna system () at the rear of a radome (), operating at relatively low radar frequencies in an amplitude comparison tracking mode, and a high-frequency (W-band) active amplitude-comparison antenna system () in the nose of the radome () and having a common boresight with the anti-radar system. The active system employs coarse phase shift steering () of the antenna 'beam' for the transmit and, optionally, also, the receive 'beam'. The high frequency and the use of phase shift steering both help to keep down the size of the active radar thus enabling it () to be positioned far forward in the nose of the radome () so as not to obscure the field of the anti-radar system ().

Radar system

A tracking radar system comprising an aerial arrangement having a plurality of outputs, means for deriving from the aerial outputs a sum signal representative of the sum of the aerial outputs and a difference signal representative of the direction of a target relative to the aerial, a receiver for processing said sum and difference signals to produce corresponding intermediate frequency sum and difference signals, means for comparing the intermediate frequency sum signal with the output of an oscillator in a first phase-locked loop and using the resulting signal to control the oscillator frequency so as to cause the oscillator to lock on to the frequency of the intermediate frequency sum signal, a phase-sensitive detector for comparing the intermediate frequency difference signal with the output of the oscillator to produce an output signal representative of the phase difference between the sum and difference signals, and bandwidth alteration means responsive to the sum signal to alter the bandwidth of the first phase-locked loop.

Tracking radar systems

Radar seeker transient suppressor

A method of preventing interference between `friendly` pulse doppler radars when in action against a common target or adjacents targets. Despite considerable separation of the radar r.f's the pulsed signals have repeated sideband pulses which may be taken by another radar as a doppler-shifted echo. This problem is to a large extent alleviated by frequency modulating the r.f. transmission at a very low cycle rate of the order of one cycle per second and at a modulation rate sufficient to indicate to a receiving radar that the source could not be a target accelerating at such a high rate.

Pulse doppler radar system

A static-split tracking radar system with substantially improved performance. The system includes parallel signal processing channels for processing sum and difference signals from a target-seeking aerial array, to produce target tracking signals. Novel means are provided for trimming relative phase and gain of these channels to achieve substantially perfect matching, which gives a receiver stability sufficient for homing head use in a guided missile system. The system also includes a receiver for acquiring a reference frequency signal, the receiver having novel bandwidth adaptation and doppler tracking facilities. Other novel features provide improved clutter rejection and jamming immunity.

Static-split tracking radar systems

A missile guidance system having means for deriving from a target angle tracking loop a signal indicative of an apparent movement of a target off a missile-to-target sight line caused by a change in missile attitude, and means for feeding said apparent movement signal into a space stabilization loop to adjust the position of the aerial to compensate for said apparent movement.

A signal acquisition circuit for a missile guidance system has a phase lock loop which is responsive to incoming signals received from a target and will lock on to the frequency of the received signal. The bandwidth of the phase lock loop is altered in dependence on the signal being received in order to distinguish between a valid target and noise.

Signal acquisition circuit with variable bandwidth phase locked loop

A phase-lock loop system with particular use in radar tracking systems is disclosed. From a number of input signals of varying frequencies such as a carrier frequency and several side band frequencies the system can lock into phase and frequency with the input which has the largest amplitude by sweeping across a predetermined range of frequencies and allowing the phase-lock loop to operate only when a predetermined amplitude is exceeded.

Growing community of inventors

Radlett, United Kingdom

Michael A Jones