Texas Instruments Corporation

The United States of America As Represented by the Secretary of

James Benedict Couvillon

Robert A Maher

William Dorsey Daniels

Ronald Lee Gassner

Disclosed is a pulsed FM receiver with automatic centering of the intermediate frequency at the true center of the input filter passband. The frequency standard of the frequency discriminator which controls the local oscillator frequency is adjusted to produce zero discriminator output during the period between signal pulses. The discriminator frequency standard remains automatically aligned with the center of the input filter passband and the input bandwidth may then be reduced for optimum receiver sensitivity.

Automatically centered pulsed FM receiver

Disclosed is improved distance measuring equipment comprising an airborne FM coded, chirp, interrogator transmitter in combination with a weighted matched receiver in a ground transponder. The airborne transmitter produces a long low power frequency modulated output pulse. Detection in the transponder receiver is accomplished by pulse compression matched filter techniques.

Distance measuring equipment

Disclosed is a magnetron powered selectable pulsewidth radar system having minimum receiver bandwidth for each pulsewidth and automatic centering of the intermediate frequency at the true center of the input filter pass band. A frequency discriminator adjusts the local oscillator frequency after each transmitted pulse to cause the intermediate frequency on the return of that pulse to equal an internal adjustable frequency reference. The filtered IF noise signal between received pulses is compared to the internal reference by the frequency discriminator and its output is used to adjust the reference to equal the center frequency of the actual receiver input pass band.

Automatically centered pulsed radar receiver

Disclosed is a zero center frequency IF system having an all digital complex multiplier in which DC components in the IF signals are removed from an A/D converter output. Any DC level which reaches the input of the A/D converter or any misalignment in the A/D converter causes the digital outputs to contain unequal numbers of positive and negative words. The sign bit of the digital output is coupled to the input of an integrator which generates a DC output proportional to the DC offset in the A/D converter output. The integrator output is substracted from the IF signal coupled to the input of the A/D converter and cancels any DC components present.

Growing community of inventors

Dallas, TX, United States of America

James Benedict Couvillon