Yupiteru Industries Co., Ltd.

Takeshi Hatasa

Hisao Ono

A wideband microwave detector includes: a first local oscillator outputting a first local oscillation output containing a basic wave component, a secondary high harmonic component and a tertiary high harmonic component and being swept within a predetermined frequency range; a first mixer performing frequency mixing of the first local oscillation output and an antenna input input through an antenna and outputting a first mixing output; a second local oscillator outputting a second local oscillation output; a second mixer performing frequency mixing of the first mixing output and the second local oscillation output for generating a second mixing output, a single frequency discriminator for detecting a specific frequency in a discrimination input, and mode selector switch alternately switching a single super heterodyne reception mode, in which the first mixing output of the first mixer is introduced into the frequency discriminator as the discrimination input and a double super heterodyne reception mode, in which the second mixing output of the second mixer is introduced into the frequency discriminator as the discrimination input, in synchronism with sweep operation of the first local oscillator.

Wideband microwave detector

A microwave detector comprises a one side opened hollow member having a first portion and a second portion, a printed circuit board, on which a metal layer is formed on one side, the metal layer on the printed circuit board cooperating with the hollow member for forming a horn antenna at a position corresponding to the first portion and an oscillation cavity for housing a first local oscillator at a position corresponding to the second portion, the horn antenna including a throat portion communicated with the oscillation cavity, a first mixing circuit disposed in the throat portion, an intermediate frequency processing circuit formed on the other side of the printed circuit board and including a first intermediate frequency filter, a second mixing circuit and a second local oscillator, and means for establishing electrical connection between the first mixing circuit and the intermediate frequency processing circuit across the printed circuit board.

Structure of multi-band microwave detector

A structure of a reception frequency converting portion of a multi-band microwave detector, and including a microwave circuit comprises a horn antenna, two-port cavity integrally formed with the horn antenna and having one port communicated with a throat portion of the horn antenna, one-port cavity integrally formed with the two-port cavity and communicated with the other port of the two-port cavity, a mixer diode located at the throat portion of the horn antenna, a first local oscillator arranged within the two-port cavity, and a second local oscillator arranged within the one-port cavity.

Structure of reception frequency converting portion in a multi-band

A microwave detector arranged in such a manner that a horn antenna element is fastened to the surface of a microstrip plate having a ground plate on its reverse side. The horn antenna element and the ground plate constitute a microwave receiving antenna so that the height of the microstrip plate is lowered. As a result, a compact microwave detector can be constituted.

Microwave detector and horn antenna structure therefor

A multi-band microwave detector is designed for detecting microwaves of a plurality of target bands from a specific source and a reference band, which target band includes a specific target band. The multi-band microwave detector comprises a super heterodyne receiving means cyclically performing receiving operation of the microwaves in the target band and the reference band in time sharing manner, a signal discrimination means for discriminating reception outputs from the receiving means for respective bands for generating detecting signals representative of the results of discrimination, means responsive to a detecting signal indicative of detection of the received microwave of one of the target bands other than the specific target band for triggering an alarm, and means responsive to a detecting signal indicative of detection of the received microwave of the specific target band and to the detection signal indicative of detection of the received microwave of the reference band, for triggering the alarm only when the detecting signal indicative of detection of the received microwave of the specific target band is present under absence of the detection signal indicative of detection of the reference band.

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Toyota, Japan

Takeshi Hatasa