Frequency conversion circuit

Claim 2

A frequency conversion circuit comprising: a differential pair of active semiconductive elements having outputs coupled together; means for biasing said active elements only into non-linear operating regions thereof; means for applying, in opposite phases, a superposition signal composed of signals of first and second frequencies to respective control inputs of said active elements; and a common load for differential outputs of said active elements, a frequency-converted signal of said first and second signals produced by non-linear operation of said active elements being present across said load.

Claim 3

The circuit as claimed in claim 1 wherein said active elements comprise bipolar transistors, and said control inputs and said differential outputs are bases and collectors of said bipolar transistors, respectively.

Claim 4

The circuit as claimed in claim 1 wherein said active elements comprises field-effect transistors, and said control inputs and said differential outputs are gate electrodes and drain electrodes of said field-effect transistors.

Claim 5

The circuit as claimed in any of claims 1-3 wherein said common load comprises a resonant circuit having a resonant frequency substantially equal to the frequency of a desired signal.

Claim 6

The frequency conversion circuit of any of claims 1-3 wherein said means for applying said superposition signal comprises a transformer having a primary winding to which said first and second signals are coupled and a center-tapped secondary winding, ends of said secondary winding being coupled to said respective control inputs of said active elements.

Claim 7

A frequency conversion circuit comprising: a first transformer, a superposition signal composed of signals of first and second frequencies being coupled to a first terminal of a primary winding of said first transformer, a second terminal of said primary winding being coupled to a reference voltage point, said first transformer having a center-tapped secondary winding, a center tap of said secondary winding being coupled to said reference voltage point; first and second bipolar transistors, said first and second bipolar transistors having emitters coupled together and coupled to said reference voltage point and collectors coupled together; first and second capacitors coupling, respectively, first and second ends of said secondary winding of said first transformer to bases of said first and second transistors; means for supplying bias to said bases of said first and second transistors; a third capacitor and a second transformer, said third capacitor being coupled across a first winding of said second transformer, a first terminal of said third capacitor being coupled to said collectors of said first and second transistors and a second terminal of said third capacitor being coupled to a voltage source for biasing said transistors only in their non-linear region, said second transformer having a secondary winding, a first terminal of said second winding being coupled to said reference voltage point, and an output signal being produced at a second terminal of said second winding.

Claim 8

A frequency conversion circuit comprising: a first transformer, a superposition signal composed of signals of first and second frequencies being coupled to a first terminal of a primary winding of said first transformer, a second terminal of said primary winding being coupled to a reference voltage point, said first transformer having a center-tapped secondary winding, a center tap of said secondary winding being coupled to said reference voltage point; first and second bipolar transistors, said first and second bipolar transistors having emitters coupled together and coupled to said reference voltage point and collectors coupled together; first and second capacitors coupling, respectively, first and second ends of said secondary winding of said first transformer to bases of said first and second transistors; means for supplying bias to said bases of said first and second transistors; a third capacitor and a second transformer, said third capacitor being coupled across a first winding of said second transformer, a first terminal of said third capacitor being coupled to said collectors of said first and second transistors and a second terminal of said third capacitor being coupled to a voltage source for biasing said transistors only in their non-linear region, said second transformer having a secondary winding, a first terminal of said second winding being coupled to said reference voltage point, and an output signal being produced at a second terminal of said second winding.