Patent ID: 7109793

Claim:
A high frequency differential circuit which operates in accordance with a difference in potential between two signals, the circuit comprising: a differential amplification circuit operable to amplify a difference in potential between a first input signal and a second input signal, the first input signal and the second input signal being in reverse phase with each other, the first input signal being input into an input end of a first active element, the second input signal being input into an input end of a second active element, the first and second active elements being differentially connected to each other, and the differential amplification circuit being operable to output a first output signal from an output end of the first active element and a second output signal from an output end of the second active element; a first passive element circuit connected between the input end of the first active element and the output end of the second active element; and a second passive element circuit connected between the input end of the second active element and the output end of the first active element, wherein an impedance of the first passive element circuit is set so as to transfer a signal having a sufficient intensity to cancel a feedback signal fed back from the output end of the first active element to the input end of the first active element, and wherein an impedance of the second passive element circuit is set so as to transfer a signal having a sufficient intensity to cancel a feedback signal fed back from the output end of the second active element to the input end of the second active element.