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US 5,416,449 AGranted
Modulator with harmonic mixers
AssigneeSynergy Microwave Corporation
InventorShankar R. Joshi
Life of this patent
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Abstract
An improved modulator circuit for mixing a modulation signal with a carrier signal includes first and second harmonic mixers which are operative to produce modulated output signals at an output frequency corresponding to both the sum and the difference of the modulation signal frequency and the even harmonic frequencies of the carrier signal frequency. In one configuration employing a 90.degree. hybrid, the output signals of the harmonic mixers are combined to produce a single sideband modulated output signal. A novel harmonic mixer circuit is also provided along with demodulator circuits and methods of modulating and demodulating modulation signals.
Claims39
A modulator circuit comprising:
- a first harmonic mixer having first and second inputs and an output for providing a first electrical output signal;
- a second harmonic mixer having first and second inputs and an output for providing a second electrical output signal;
- carrier input means for providing first and second electrical input carrier signals to said first inputs of said first and second harmonic mixers respectively, said first and second carrier signals having a carrier frequency;
- and
- modulation input means for providing first and second electrical input modulation signals to said second inputs of said first and second harmonic mixers respectively, said first and second modulation signals having a modulation frequency and a 90.degree. phase difference therebetween,
- said first and second harmonic mixers being operative to produce said first and second output signals having output frequencies corresponding to both the sum and the difference of said modulation frequency and even harmonic frequencies of said carrier frequency.
3 more elements
The circuits as claimed in claim 7, wherein said single sideband frequency corresponds to the difference of said modulation frequency and a second harmonic frequency of said carrier frequency.
A harmonic mixer comprising:
- a first transformer comprising primary and secondary windings;
- a second transformer comprising a transmission line formed by a pair of conductors;
- a first input being coupled to said primary windings of said first transformer;
- a second input coupled to said secondary windings of said first transformer;
- an output coupled to one of said conductors of said transmission line;
- and
- a diode ring quad having a first diode junction between first and second adjacent diodes, a second diode junction between said second and third adjacent diodes, a third diode junction between said third and fourth adjacent diodes and a fourth diode junction between said fourth and said first adjacent diodes, said first diode junction being coupled to said secondary windings of said first transformer and said second and said fourth diode junctions being coupled to the other one of said conductors of said transmission line.
4 more elements
A demodulator circuit comprising:
- a first harmonic mixer having first and second inputs and an output for providing a first electrical output signal;
- a second harmonic mixer having first and second inputs and an output for providing a second electrical output signal;
- carrier input means for providing first and second electrical input carrier signals having a carrier frequency to said first inputs of said first and second harmonic mixers respectively, said first and second carrier signals having a carrier frequency;
- and
- modulated input means for providing first and second electrical input modulated signals to said second inputs of said first and second harmonic mixers respectively, said first and second modulated signals having a 90.degree. phase difference therebetween and a modulated frequency corresponding to either the sum or the difference of a modulation frequency of a modulation signal and at least one even harmonic frequency of said carrier frequency,
- said first and second harmonic mixers being operative to produce first and second demodulated output signals at said modulation frequency with a 90.degree. phase difference therebetween.
3 more elements
A method of modulating electrical signals comprising the steps of:
- (a) providing a first electrical input carrier signal to a first input of a first harmonic mixer;
- (b) providing a second electrical input carrier signal to a first input of a second harmonic mixer, said first and second carrier signals having a carrier frequency;
- (c) providing a first electrical input modulation signal to a second input of said first harmonic mixer;
- (d) providing a second electrical modulation signal to a second input of said second harmonic mixer, said first and second modulation signals having a modulation frequency and a 90.degree. phase difference therebetween;
- (e) mixing said first carrier signal and said first modulation signal in said first harmonic mixer to produce a first output signal;
- and
- (f) mixing said second carrier signal and said second modulation signal in said second harmonic mixer to produce a second output signal,
- said first and second output signals having an output frequencies at the sums and the differences of said modulation frequency and even harmonic frequencies of said carrier frequency.
5 more elements
A method of demodulating an electrical signal comprising the steps of:
- (a) providing a first electrical input carrier signal to a first input of a first harmonic mixer;
- (b) providing a second electrical input carrier signal to a first input of a second harmonic mixer, said first and second signals having a carrier frequency;
- (c) providing a first electrical input modulated signal to a second input of said first harmonic mixer;
- (d) providing a second electrical input modulated signal to a second input of said second harmonic mixer, said first and second modulated signals having a 90.degree. phase difference therebetween and a modulated frequency at either the sum or the difference of a modulation frequency of a modulation signal and even harmonic frequencies of said carrier frequency;
- (e) mixing said first carrier signal and said first modulated signal in said first harmonic mixer to form a first demodulated output signal;
- and
- (f) mixing said second carrier signal and said second modulated signal in said second harmonic mixer to form a second demodulated output signal,
- said first and second demodulated output signals having said modulation frequency and a 90.degree. phase difference therebetween.
5 more elements
Dependencies are inferred from the claim text.