Abstract: There is provided a highly accurate velocity sensor having a reduced detection error. A sensor circuit unit generates an electromagnetic wave and emits it from a transmission antenna. Furthermore, a reception antenna receives a reflection wave from the ground and a mixer mixes it with a local signal, thereby generating a low-frequency signal. The electromagnetic wave emitted from the sensor circuit unit shapes a beam by a dielectric lens before emitting it toward the ground. Here, the beam shape is such that the beam width in the vicinity of the sensor is smaller than the beam width in the vicinity of the ground.

Abstract: There is provided a radar system for improving distance resolution while preventing generation of ghost by an object located in the outside of the effective distance for detection. In this radar system, the signal generated by a voltage-controlled oscillator is transmitted only for the predetermined period by turning ON a switch only for the predetermined time length t1 with an interval of the predetermined period t2. Moreover, the time for detecting the receiving signal is limited to the predetermined period t3 (=t1) from the timing of transmission of the transmitting signal and the reflection signal from the object located in the outside of the effective distance is eliminated by limiting a local signal inputted to a mixer to the period t1.

Abstract: A monopulse radar system aims to correct an amplitude error and a phase error developed between receiving channels and improve the accuracy of a detected angle. To achieve the above aim, part of a transmit signal is supplied to respective channels on the receiving side through a signal transmission line for calibration. At this time, the gains of a variable phase shifter and a variable gain amplifier are adjusted so that an azimuth angle of a pseudo target, based on a signal for calibration, which is calculated by signal processing means, reaches a predetermined angle. Therefore, calibration work is simplified and an angular correction can be automated. Therefore, the present monopulse radar system is capable of coping even with variations in characteristic after product shipment due to environmental variations and time variations in parts characteristic.

Abstract: The oscillator includes an active device, a substrate, a microstrip line formed on the substrate, and a dielectric block. The resonator is made up with the microstrip line and the dielectric block that is disposed so as to couple with the microstrip line. The active device produces a negative resistance in a desired oscillation frequency band. The dielectric block is set such that a resonance frequency of the lowest order mode of the dielectric block is lower than a desired oscillation frequency, and the resonance frequency of one of the higher order modes coincides with the desired oscillation frequency. The oscillator is generated with the higher order mode of the resonator. Thus, the invention provides at a low cost a millimeter wave band oscillator of a low phase noise by using this oscillator, and a transmitter-receiver module and a radar system applying this oscillator to the local signal generator.

Abstract: The invention intends to provide a sensor module suitable for miniaturization and reduction in costs, in the radar sensor that uses a millimeter or sub-millimeter wave signal of which frequency is more than 20 GHz. To accomplish this problem, the radar sensor is integrated into a one chip MMIC, in which an active circuit including an oscillator and a mixer is formed with an antenna on one semiconductor substrate. Further, the MMIC is sealed with a resin package. A dielectric lens is formed on the resin package over the antenna to attain a desired beamwidth. Thereby, the lens and the resin package can integrally be formed by a metal mold, thus reducing the cost.

Abstract: The invention intends to provide a sensor module suitable for miniaturization and reduction in costs, in the radar sensor that uses a millimeter or sub-millimeter wave signal of which frequency is more than 20 GHz. To accomplish this problem, the radar sensor is integrated into a one chip MMIC, in which an active circuit including an oscillator and a mixer is formed with an antenna on one semiconductor substrate. Further, the MMIC is sealed with a resin package. A dielectric lens is formed on the resin package over the antenna to attain a desired beamwidth. Thereby, the lens and the resin package can integrally be formed by a metal mold, thus reducing the cost.

Abstract: The invention intends to provide a sensor module suitable for miniaturization and reduction in costs, in the radar sensor that uses a millimeter or sub-millimeter wave signal of which frequency is more than 20 GHz. To accomplish this problem, the radar sensor is integrated into a one chip MMIC, in which an active circuit including an oscillator and a mixer is formed with an antenna on one semiconductor substrate. Further, the MMIC is sealed with a resin package. A dielectric lens is formed on the resin package over the antenna to attain a desired beamwidth. Thereby, the lens and the resin package can integrally be formed by a metal mold, thus reducing the cost.

Abstract: A multiple PLL oscillator for oscillating and outputting a plurality of frequencies having a predetermined step frequency, comprising a first and a second reference frequency sources, a switch for selecting the ore of outputs of the first and the second reference frequency sources alternatively and at predetermined time interval, and a PLL frequency synthesizer generating a millimeter wave oscillation output corresponding to each of the first and second reference frequency sources.

Abstract: A monopulse radar system aims to correct an amplitude error and a phase error developed between receiving channels and improve the accuracy of a detected angle. To achieve the above aim, part of a transmit signal is supplied to respective channels on the receiving side through a signal transmission line for calibration. At this time, the gains of a variable phase shifter and a variable gain amplifier are adjusted so that an azimuth angle of a pseudo target, based on a signal for calibration, which is calculated by signal processing means, reaches a predetermined angle. Therefore, calibration work is simplified and an angular correction can be automated. Therefore, the present monopulse radar system is capable of coping even with variations in characteristic after product shipment due to environmental variations and time variations in parts characteristic.

Abstract: The invention intends to provide a sensor module suitable for miniaturization and reduction in costs, in the radar sensor that uses a millimeter or sub-millimeter wave signal of which frequency is more than 20 GHz. To accomplish this problem, the radar sensor is integrated into a one chip MMIC, in which an active circuit including an oscillator and a mixer is formed with an antenna on one semiconductor substrate. Further, the MMIC is sealed with a resin package. A dielectric lens is formed on the resin package over the antenna to attain a desired beamwidth. Thereby, the lens and the resin package can integrally be formed by a metal mold, thus reducing the cost.

Abstract: One of outputs of reference frequency sources 11 and 12 is selected by a switch 13, as a reference frequency signal and compared with the phase of an output of a frequency divider 19 by a phase comparator 14. A voltage controlled oscillator 16 is controlled by a result of comparison. An output of the voltage controlled oscillator 16 and an output of another reference frequency source 18 are mixed by a mixer 17. An upper side band frequency signal of the mixer 17 is used as an output of the multiple PLL oscillator, and a lower side band frequency signal of the mixer 17 is supplied to the frequency divider 19. With the configuration, in the multiple millimeter PLL oscillator, even when the dividing number of frequency increases, lock-up time to reach a desired frequency can be shortened. Thus, stability of a PLL can be improved and specifications of the oscillation frequency of the millimeter wave band and a step frequency of hundreds kHz can be realized.

Abstract: The invention intends to provide a sensor module suitable for miniaturization and reduction in costs, in the radar sensor that uses a millimeter or sub-millimeter wave signal of which frequency is more than 20 GHz. To accomplish this problem, the radar sensor is integrated into a one chip MMIC, in which an active circuit including an oscillator and a mixer is formed with an antenna on one semiconductor substrate. Further, the MMIC is sealed with a resin package. A dielectric lens is formed on the resin package over the antenna to attain a desired beamwidth. Thereby, the lens and the resin package can integrally be formed by a metal mold, thus reducing the cost.

Abstract: A monopulse radar system aims to correct an amplitude error and a phase error developed between receiving channels and improve the accuracy of a detected angle.

Abstract: A dielectric resonator oscillator with little manufacturing variations, low cost, and low phase noise characteristic, in which one terminal of an active element of a monolithic integrated circuit 24 is connected to a coupled line 3 formed on a dielectric substrate 21 via a wire 23, a dielectric resonator 1 having the shape of a column whose bottom face has a polygon shape having five or more sides is formed on the dielectric substrate 21, and the dielectric resonator 1 is electromagnetically coupled to the coupled line 3. When a transmitting and receiving module for use in a radar system is formed by using the dielectric resonator oscillator, the system can be formed at low cost and the maximum distance to an object which can be detected can be increased.

Abstract: The oscillator includes an active device, a substrate, a microstrip line formed on the substrate, and a dielectric block. The resonator is made up with the microstrip line and the dielectric block that is disposed so as to couple with the microstrip line. The active device produces a negative resistance in a desired oscillation frequency band. The dielectric block is set such that a resonance frequency of the lowest order mode of the dielectric block is lower than a desired oscillation frequency, and the resonance frequency of one of the higher order modes coincides with the desired oscillation frequency. The oscillator is generated with the higher order mode of the resonator. Thus, the invention provides at a low cost a millimeter wave band oscillator of a low phase noise by using this oscillator, and a transmitter-receiver module and a radar system applying this oscillator to the local signal generator.