Abstract: A microwave detector for detecting faint detection target microwave signals is constructed from a heterodyne-type reception portion equipped with an antenna for picking up microwave signals, a local oscillator for repeatedly carrying out a sweep operation, and a mixer for frequency mixing the output from the antenna with the output from the local oscillator, wherein the heterodyne reception portion outputs detected wave signals based on the output from the mixer; a digital processing portion which receives the detected wave signals outputted from the reception portion, wherein the digital processing portion is designed to output a High pulse when the level of the detected wave signals reaches or exceeds a prescribed reference level, and a Low pulse when the level of the detected wave signals is below the reference level; a sweep control portion for controlling the sweep operation of the local oscillator based on the High and Low pulses outputted from the digital processing portion; and a judgement portion for

Abstract: A microwave detector for detecting a target microwave signal carries out detection by dividing the target bandwidth into a plurality of partitioned bands which are each repeatedly swept a prescribed number of times, with the detected wave outputs from each sweep being added together to form an added detected wave output for each partitioned band, and due to mutual cancellation of the white noise, the presence of even a faint target microwave signal within a partitioned band will increase to a detectable level in the added detected wave output of such partitioned band, and because the detection process is carried out separately for each partitioned band, the microwave detector only needs enough memory capacity to store the added detected wave output of a single partitioned band.

Abstract: A multi-band microwave detector includes an antenna, a plurality of reception systems connected to the antenna in a parallel arrangement, a judgement circuit for judging whether or not a microwave signal detected by the reception systems is a detection target microwave signal, an alarm circuit for outputting an alarm when the judgement circuit judges the detected microwave signal to be a detection target microwave signal, wherein each reception system is constructed from a superheterodyne reception circuit having a prescribed intermediate frequency that is mutually different from the intermediate frequencies of all the other reception systems, and wherein all the reception systems are operated simultaneously during one detection cycle.

Abstract: In order to detect microwaves from radar type speed measurement devices and microwaves leaking out of reverse detectors without being detected by such reverse detectors, a microwave detector is provided with a super-heterodyne type reception circuit for cyclically performing reception operations to receive target microwave frequencies of prescribed microwave bands, the reception circuit including a first local oscillator which can carry out a fixed oscillation at a prescribed frequency or a sweep of a prescribed frequency range established slightly outside the frequency range of the local oscillator of a reverse detector, and a plurality of second local oscillators having different oscillation frequencies, whereby the reception circuit is able to receive microwaves in the target bands and microwaves leaking out of the local oscillator of a reverse detector.

Abstract: A double superheterodyne type microwave detector is constructed from a reception antenna; a first local oscillator; a second local oscillator; reception means for detecting microwaves having prescribed frequencies based on signals obtained by carrying out a first mixing in which the output of the first local oscillator is mixed with the microwaves picked up by the antenna, and a second mixing in which the signals obtained from the first mixing are mixed with the output of the second local oscillator; judgement means for judging whether or not an actual microwave signal which forms a detection target has been detected by the reception means; alarm means for outputting an alarm when the judgement means judges an actual microwave signal to have been received by the reception means; and first control means for suspending the first mixing when the reception means detects a microwave signal having a prescribed frequency; wherein the judgement of whether or not the prescribed frequency microwave signal detected by t

Abstract: A microwave detector includes a horn antenna and cavity formed by covering a metallic film of a printed substrate with an opened bottom microwave circuit component, and further includes a mixer diode which is positioned at the feeding point of the horn antenna and sandwiched between the microwave circuit component and the printed substrate, the mixer diode including a mixer diode substrate having a first protruding portion at a first end of the mixer diode substrate and a second protruding portion at a second end of the mixer diode substrate, separate anode and cathode electrode patterns formed on a surface of the substrate which includes the protruding portions, and a beam-lead-type or flip-chip-type diode which is mounted to a surface of the mixer diode substrate near the center thereof, the beam-lead-type or flip-chip-type diode having an anode and a cathode which are surface mounted to the anode and cathode electrode patterns to form electrically conducting pathways therewith, wherein the first and second

Abstract: An open-space battery housing portion 9a is integrally formed in a portion of a connecting mechanism 11 of a device main body 1 to house a secondary battery 6 between a main circuit substrate 3 and a connecting plate 22 when the connecting plate 22 is coupled with the connecting mechanism 11, in which the connecting plate 22 also serves as a cover member for the battery housing portion 9a, whereby the secondary battery 6 can be removed from the battery housing portion 9a when the connecting plate 22 is uncoupled from the connecting mechanism 11.

Abstract: A thin charging device having excellent portability is provided for charging a battery pack while the battery pack remains housed within a communication device. The charging device (10) is constructed from a flat rectangular shaped main body (12) and a cover (13) which is fixed to a rotation shaft (23) so as to be rotatable with respect to the main body to allow the cover to be positioned in either an open or closed position. When the cover is in the closed position, it covers charging terminals (20) provided on the top of the main body and makes the overall dimensions of the charging device roughly equal to the dimensions of the main body. On the other hand, when the cover is placed in the open position, the cover is maintained at such open position by the provision of support means (34), (35), (37).

Abstract: 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 whic

Abstract: A power-saving type multi-band microwave detector is operable in a high sensitivity mode and a low sensitivity mode for achieving higher sensitivity for both non-modulated and modulated microwaves to make the detecting operation reliable without causing significant increase of power consumption. The power-saving type multi-band microwave detector includes a receiver circuit including a local oscillator for generating an oscillation output and means for sweeping the frequency of the oscillation output over a predetermined reception band, a power supply for periodically supplying a power for the receiver circuit to maintain the latter active while the power is supplied, and control circuit for controlling the receiver circuit and the power supply means for an intermittent microwave receiving operation.

Abstract: 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.

Abstract: 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.

Abstract: A vibration sensor is secured to an object whose vibrations are to be sensed, and includes a vibration plate capable of resonating at one of first resonance frequencies within a specific high frequency region of the frequencies at which the object can vibrate. A vibration element capable of resonating at one of second resonance frequencies within a specific low frequency region of the frequencies at which the object can vibrate is connected to the vibration plate so that the vibration resulting from the resonance of the vibration element is transmitted to the vibration plate. Further, a piezoelectric transducer element is fixed to the vibration plate, and is able to generate an electric signal in response to the stress applied by the vibration plate when this plate vibrates. Thus, it is possible, with a single sensor, to sense both vibrations composed of relatively high frequency components and vibrations composed of relatively low frequency components.

Abstract: 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.

Abstract: 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.