Showing papers on "Comb generator published in 1980"

Comb filter device

Abstract: A comb filter device has two operation modes, one mode being a conventional comb filter when input signals have high correlation between sequential lines, and the other mode being a simple amplifier when input signals have low or no line correlation. Therefore, this comb filter has little deterioration of vertical resolution of a television picture.

Audio distortion eliminator

Abstract: An audio distortion elimination circuit is provided which eliminates the effects of periodic decreases in signal amplitude of an audio signal. A comb filter includes an undelayed signal path, a signal path including a delay line and a combining circuit coupled between a source of audio signals and an audio output circuit. The combining circuit combines the delayed and undelayed audio signals to provide a response for the comb filter which is a function of the delay of the delay line and exhibits periodically recurring points of maximum attenuation at the fundamental frequency of the periodic decreases in signal amplitude and at harmonics thereof. The comb filter may be made adaptive so that comb filtering is provided only during reception of a distorted signal.

Injection locked saw oscillators

Abstract: SAW oscillators are finding increased application in direct frequency synthesizers due to their excellent phase noise and good temperature stabil ity. In such applications it is often desirable to injection lock a bank of SAW oscillators to a single reference to establish coherence and improve stability. The injection locking properties of SAW oscillators have therefore been investigated. It has been found that with minor modification, the classic theory of injection locked oscillators can be applied to SAW oscillators. As the theory p redicts, phase slope is the delay line parameter which establishes the injection locking p roperties of SAW oscillators. I njection locking bandwidth can be calculated from phase slope and the ratio of injected voltage and oscillator signal levels. Data is presented showing the excellent fit of theoretical and measured injection locking bandwidth for SAWs of various delay times. standing of injection locking, a bank of SAW oscillators has been fabricated and locked to a comb generator. Data for this circuit is also presented. Based on this under