Frequency converter and transmitter

A frequency converter for converting frequencies of a positive-phase input signal and a negative-phase input signal into other frequencies to obtain a positive-phase output signal and a negative-phase output signal, the positive-phase input signal being inputted into a positive-phase input terminal, the negative-phase input signal being inputted into a negative-phase input terminal, the positive-phase output signal being outputted from a positive-phase output terminal and the negative-phase output signal being outputted from a negative-phase output terminal, comprising:

• a first pair of transistors configured to converting the frequency of the positive-phase input terminal into other frequency, and including a first transistor and a second transistor,
• the first transistor including
• a source terminal being connected to the positive-phase input terminal,
• a drain terminal being connected to the positive-phase output terminal, and
• a gate terminal being supplied with a positive-phase local signal;
• and
• the second transistor including
• a source terminal being connected to the positive-phase input terminal,
• a drain terminal being connected to the negative-phase output terminal, and
• a gate terminal being supplied with a negative-phase local signal;
• a second pair of transistors configured to converting the frequency of the negative-phase input terminal into other frequency, and including a third transistor and a fourth transistor,
• the third transistor including
• a source terminal being connected to the negative-phase input terminal,
• a drain terminal being connected to the positive-phase output terminal, and
• a gate terminal being supplied with the negative-phase local signal;
• and
• the fourth transistor including
• a source terminal being connected to the negative-phase input terminal,
• a drain terminal being connected to the negative-phase output terminal, and
• a gate terminal being supplied with the positive-phase local signal;
• a third pair of transistors configured to converting the frequency of the positive-phase input terminal into other frequency, and including a fifth transistor and a sixth transistor,
• the fifth transistor including
• a source terminal being connected to the positive-phase input terminal,
• a drain terminal being connected to the positive-phase output terminal, and
• a gate terminal being supplied with a positive-phase local signal;
• and
• the sixth transistor including
• a source terminal being connected to the positive-phase input terminal,
• a drain terminal being connected to the negative-phase output terminal, and
• a gate terminal being supplied with a negative-phase local signal;
• a fourth pair of transistors configured to converting the frequency of the negative-phase input terminal into other frequency, and including a seventh transistor and a eighth transistor,
• the seventh transistor including
• a source terminal being connected to the negative-phase input terminal,
• a drain terminal being connected to the positive-phase output terminal, and
• a gate terminal being supplied with the negative-phase local signal;
• and
• the eighth transistor including
• a source terminal being connected to the negative-phase input terminal,
• a drain terminal being connected to the negative-phase output terminal, and
• a gate terminal being supplied with the positive-phase local signal;
• and
• a switch to switch whether or not the third pair of transistors and the fourth pair of transistors convert the frequencies of the positive-phase input signal and the negative-phase input signal into other frequencies, depending on frequencies of the positive-phase local signal and the negative-phase local signal.