Modulation circuit

A modulation circuit that generates an output signal obtained by modulating an input signal with a local signal, comprising:

• a local input section that receives the local signal and generates the local signal and an inverted local signal obtained by inverting the local signal;
• a signal input section that receives the input signal and generates the input signal and an inverted input signal obtained by inverting the input signal;
• a first multiplying section that outputs from a terminal that receives the input signal a first multiplied signal obtained by multiplying the local signal with the input signal;
• a second multiplying section that outputs from a terminal that receives the inverted input signal a second multiplied signal obtained by multiplying the inverted local signal with the inverted input signal;
• an output section that adds the first multiplied signal to the second multiplied signal and generates the output signal;
• and
• a transmission line that has an electrical length according to a predetermined frequency as the frequency of the input signal,
• wherein the first multiplying section and the second multiplying section each include a transistor in which a source terminal is connected to a reference potential, a drain terminal is connected to the transmission line and the signal input section, and a gate terminal receives the signal from the local input section.