HIGH-FREQUENCY SENSOR

摘要

PPROBLEM TO BE SOLVED: To provide a high-frequency sensor loading a filter circuit for suppressing a reflection of higher harmonic waves to the oscillator side on a transmission line from an oscillator which produces a radiowave of the sensor to an antenna for radiating the radiowave to the outside. PSOLUTION: The high-frequency sensor includes: an oscillator 2 for producing a transmitting wave 1; a transmitting antenna 3 for radiating the transmitting wave to the outside; a receiving antenna 3 for receiving a reflected wave of the transmitting wave as a receiving wave; a mixer part for producing a detection signal based on the transmitting wave and the receiving wave; and a branch part for distributing and transmitting the transmitting wave produced by the oscillator to the transmitting antenna and the mixer part. A first cutoff part is provided on the transmission line connecting the oscillator with the branch part; and a second cutoff part is provided on the transmission line connecting the branch part with the mixer part. A reference potential on the transmission line is set, and a reference voltage part having a filter function of cutting off an nth-order higher harmonic wave of a high-frequency signal is disposed on the transmission line between the first cutoff part and the branch part. PCOPYRIGHT: (C)2010,JPO&INPIT