US 4,225,866 AGranted

Automatic failure-resistant radar transmitter

AssigneeInternational Telephone and Telegraph Corporation

InventorArnold M. Levine

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Abstract

Apparatus is shown for controlling pulse width in pulsed, step-wise frequency modulated transmitters employing relatively long pulse widths and receiving pulse compression. Also disclosed is a pulsed pseudo-random coded radar system having fixed code word duration. Individual solid-state, RF power amplifier modules are paralleled, all spares included, and the full parallel group is operated at a power level such that individual units operate substantially below maximum power rating. RF solid-state device life is thereby increased. Failures of individual solid-state modules are recognized by a power monitor which operates to lengthen the pulse width in the FM staircase embodiment and to increase power supply input and, therefore, peak pulse power in the pseudo-random coded embodiment, thereby restoring average nominal transmitter power, notwithstanding one or more failed solid-state RF amplifiers.

Claims4

Dependent claims

A failure resistant pulsed radar system transmitter of the FM chirp type comprising:

first means having a radio frequency input and radio frequency power output and N substantially identical solid-state radio frequency amplifier units operating in parallel electrically and each contributing 1/N of the predetermined level of the total output power of said transmitter, said units each operating at a power level below its maximum rating;
second means comprising apparatus for providing successive pulses of radio frequency energy for driving said first means, said second means varying the transmitted frequency throughout each of said successive pulses;
third means responsive to said first means power output for developing a control signal as a function of said total output power, and for applying said control signal in a manner to maintain said total output power substantially at said predetermined level by modifying the duration of each of said successive pulses;
and fourth means within said first means for substantially isolating failed ones of said modules for limiting interaction with the remaining operative modules.

1 more element

Dependencies are inferred from the claim text.