Radio communication equipment in which a negative capacitance circuit which operates under a low voltage and the negative capacitance value of which varies when a voltage is applied across control terminals is connected to a node at which mismatching occurs due to a parasitic element or at which an element value fluctuation affects the characteristics of the radio communication equipment in the connecting section between an integrated circuit or a circuit element constituting the radio communication equipment and a transmission line pattern formed on a substrate. The loss of the signal power in the radio communication equipment is minimized by equivalently optimizing the value of the parasitic element by means of the variable negative capacitance circuit. The variability in the qualities of the element or parasitic element constituting the circuit caused by the manufacture or mounting is minimized by means of the variable negative capacitance circuit. Therefore, inexpensive radio communication equipment which is reduced in manufacturing variability, has a small size, and can operate at low voltage can be obtained.

Negative capacitance circuit

Radio communication equipment using variable negative capacitance circuit

PROBLEM TO BE SOLVED: To provide a negative capacitance circuit suitable for an oscillator circuit capable of changing an oscillatory frequency within a wide frequency range.SOLUTION: The present invention comprises: a negative capacitance circuit 10 including an emitter follower circuit 1, a base ground circuit 2; a capacitor 3 provided between an output terminal of the emitter follower circuit 1 and an input terminal of the base ground circuit 2, and a resistor 4 provided between an input terminal of the emitter follower circuit 1 and an output terminal of the base ground circuit 2; an oscillator 6 that is connected with the negative capacitance circuit 10 and receives an electric current output from the output terminal of the base ground circuit 2.

Negative capacitance circuit

Citations

Radio communication equipment using variable negative capacitance circuit

Negative capacitance circuit and oscillator circuit

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