US 5,598,130 A · Phase modulator capable of individually defining modulation degree and modulation frequency

Abstract

An FM signal generator generates an FM signal obtained by frequency-modulating a reference frequency signal with a modulating frequency signal. A first mixer mixes the FM signal and an input signal having a predetermined carrier frequency and outputs a pair of frequency signals having sum and difference frequencies thereof. A first signal extracting unit extracts one of the pair of frequency signals as an intermediate frequency signal. A delay circuit delays the extracted intermediate frequency signal by a predetermined time. A second mixer mixes the delayed intermediate frequency signal and the FM signal and outputs a pair of frequency signals having sum and difference frequencies. A second signal extracting unit extracts the frequency signal of the pair of frequency signals which corresponds to the carrier frequency component as a phase-modulated signal. The modulation degree and modulation frequency in phase modulation for the phase-modulated signal can be set in wide ranges.

Claims14

Dependent claims

A phase modulator comprising:

FM signal generating means for generating an FM signal obtained by frequency-modulating a reference frequency signal with a modulating frequency signal in order to set a modulation degree and a modulation frequency in phase modulation;
first frequency conversion means for mixing an input signal having a predetermined carrier frequency with the FM signal from said FM signal generating means;
first signal extracting means for extracting one of upper and lower sideband signals obtained from said first frequency conversion means as an intermediate frequency signal;
delay means for delaying the intermediate frequency signal from said first signal extracting means by a predetermined time in order to set the modulation degree in said phase modulator;
second frequency conversion means for mixing the intermediate frequency signal delayed by said delay means with the FM signal from said FM signal generating means;
and
second signal extracting means for extracting a frequency signal corresponding to the carrier frequency component of upper and lower sideband signals obtained from said second frequency conversion means.

4 more elements

A phase modulator comprising:

FM signal generating means for generating an FM signal obtained by frequency-modulating a reference frequency signal with a modulating frequency signal in order to variably set a modulation degree and a modulation frequency in phase modulation;
first frequency conversion means for mixing an input signal having a predetermined carrier frequency with the FM signal from said FM signal generating means;
first signal extracting means for extracting one of upper and lower sideband signals obtained from said first frequency conversion means as an intermediate frequency signal;
delay means for delaying the intermediate frequency signal from said first signal extracting means by a predetermined time in order to variably set the modulation degree in said phase modulator;
second frequency conversion means for mixing the intermediate frequency signal delayed by said delay means with the FM signal from said FM signal generating means;
and
second signal extracting means for extracting a frequency signal corresponding to the carrier frequency component of upper and lower sideband signals obtained from said second frequency conversion means.

4 more elements

Dependencies are inferred from the claim text.

Phase modulator capable of individually defining modulation degree and modulation frequency

Life of this patent

Phase modulator capable of individually defining modulation degree and modulation frequency

Life of this patent

Abstract

Claims14