Miniaturized transmitter-receiver unit

摘要

A transmitter-receiver unit has an antenna patch and an IF circuit, between which there is a large frequency difference, on a first side of a multilayer substrate. A high frequency circuit (including a local oscillator and a demodulation unit) except for the IF circuit is provided on a second side of the multilayer substrate. A ground conductive pattern is provided in the interior of the multilayer substrate. The circuit conductive pattern exposed at the second side of the multilayer substrate and a feeding point of the antenna patch conduct to each other through a through hole.