Abstract:
Two receive antennas integrated with power detectors are used to align the thrust vector of a vehicle to the boresite of an automotive radar antenna mounted upon the vehicle. In the system, a signal is transmitted from the radar antenna to the Radar Test System (RTS) positioned as an amplitude only interferometer for testing the radar. Signals received by the RTS antennas are provided to amplitude detectors for generation of amplitude plots of a difference signal, or alternative signal, for display. The boresite angle of the radar antenna is then adjusted until the amplitude of the difference signal, or alternative signal, reaches a minimum to align the radar antenna boresite with the vehicle thrust vector. Additional pairs of receive antennas and detectors may be used to provide boresite alignment both in azimuth and elevation.
Abstract:
A wafer probe with built in components to perform frequency multiplication, upconversion, downconversion, and mixing typically performed by an RF module of a vector network analyzer (VNA). The wafer probe is designed for testing integrated circuits used in collision avoidance radar systems and operates over the 76-77 GHz frequency range allocated by the Federal Communications Commission (FCC) for collision avoidance radars. To minimize costs, the wafer probe preferably utilizes integrated circuits for frequency multiplication, upconversion, downconversion, and mixing manufactured for collision avoidance radar systems.
Abstract:
A radar test system for testing a collision avoidance radar system. The radar test system includes circuitry to downconvert a signal from the collision avoidance radar to an intermediate frequency signal, to delay the intermediate frequency signal to simulate the delay of a return signal from an object located a particular distance from the collision avoidance radar system, and to upconvert and transmit the intermediate frequency signal back to the collision avoidance radar system to determine if the collision avoidance radar system provides accurate distance readings. The radar test system further couples the intermediate frequency signal to a spectrum analyzer. The spectrum analyzer can be used to determine if the collision avoidance radar system is operating within the 76-77 GHz frequency band allocated by the Federal Communications Commission (FCC). The radar test system further couples the intermediate frequency signal to a power meter. The power meter can be utilized to determine the power of the signal transmitted from the collision avoidance radar system.
Abstract:
An automotive radar test system includes circuitry for multiple down and up conversions of a signal from the automotive radar. Conditioning circuitry delays an intermediate frequency signal (IF2) obtained after a second down conversion to simulate the delay of a return signal from an object located a particular distance from the automotive radar, and to attenuate the IF2 signal to simulate variable target sizes, and to generate a Doppler shift in the IF2 signal to simulate target speed. The conditioned signal is up-converted and transmitted back to the automotive radar system to determine if the automotive radar provides accurate readings for distance, size and speed. The radar test system further couples the second IF signal to a spectrum analyzer to determine if the automotive radar is operating in the desired bandwidth and to a power meter to determine if the automotive radar is transmitting at a desired power level.
Abstract:
An automobile collision avoidance radar antenna alignment system includes a first interferometer (506) with antennas (501) and (503) for alignment along an azimuth (x) axis of the collision avoidance radar antenna, and a second interferometer (508) with antennas (502) and (504) for alignment along an elevation (y) axis of the collision avoidance radar. Difference azimuth (.DELTA..sub.AZ) and difference elevation (.DELTA..sub.EL) outputs of the interferometers (506) and (508) are added (.DELTA..sub.T =.DELTA..sub.AZ +.DELTA..sub.EL) with the amplitude of (.DELTA..sub.T) provided at a power detector (526). Sum azimuth (.SIGMA..sub.AZ) and sum elevation (.SIGMA..sub.AZ) are added (.SIGMA..sub.T =.SIGMA..sub.AZ +.SIGMA..sub.EL) with the amplitude of (.SIGMA..sub.T) provided to a power detector (547). To align a collision avoidance radar antenna, the antennas of the antenna alignment system are positioned with a centerline parallel to the thrust vector of the automobile using a laser beam fixture 204. Azimuth and elevation translation errors (.DELTA.x) and (.DELTA.y) between antennas of the antenna alignment system and the antenna of the collision avoidance radar are removed by moving the antenna alignment system until the total difference signal (.DELTA..sub.T) is a minimum. The angle (.alpha.) between the boresite of the collision avoidance radar antenna and the thrust vector of the automobile is set to zero by adjusting the collision avoidance radar antenna until the total sum signal (.SIGMA..sub.T) is a maximum.
Abstract translation:汽车碰撞避免雷达天线对准系统包括:具有天线(501)和(503)的第一干涉仪(506),用于沿着防撞雷达天线的方位角(x)轴线对准;以及第二干涉仪(508),其具有天线 502)和(504),用于沿着防撞雷达的高度(y)轴进行对准。 在功率检测器(526)处提供具有(DELTA T)幅度的干涉仪(506)和(508)的差分方位角(DELTA AZ)和差分高程(DELTA EL)输出(DELTA T = DELTA AZ + DELTA EL) )。 加上方位角(SIGMA AZ)和总高程(SIGMA AZ)(SIGMA T = SIGMA AZ + SIGMA EL),其幅度为(SIGMA T)提供给功率检测器(547)。 为了对准碰撞避免雷达天线,使用激光束固定装置204将天线对准系统的天线定位成与汽车的推力矢量平行的中心线。方位角和仰角平移误差(DELTA x)和(DELTA y) 通过移动天线对准系统直到总差分信号(DELTA T)为最小值来去除天线对准系统的天线和避碰雷达的天线。 避碰雷达天线的射孔与汽车的推力矢量之间的角度(α)通过调整避雷雷达天线直到总和信号(SIGMA T)最大为止设置为零。
Abstract:
A measurement system is provided which comprises: source circuit for receiving feedback signals and for providing respective signals at respective discrete frequencies in a prescribed microwave frequency range, wherein the respective provided signals at respective discrete frequencies are substantially phase locked to at least one downconverted signal in response to the feedback signals; downconverting circuit for linearly downconverting the respective provided signals and for providing the at least one respective downconverted signal; and phase detector circuit for receiving the at least one respective downconverted signal and for providing the feedback signals.
Abstract:
A transponder (200) is attached to a laser alignment fixture (210) and used to align an automobile collision avoidance radar antenna boresite with the thrust vector of the vehicle. The alignment fixture (210) has attached reflectors for alignment with two laser beams. To align the collision avoidance radar, the transponder (200) is positioned along the thrust vector of the automobile using a first laser beam (203) aligned perpendicular to a wheel axle. The first laser beam (203) is aligned when transmitted from the wheel axle onto a first piece of reflective material attached to the alignment fixture (210). A second laser (216) is provided parallel to the centerline of the collision avoidance radar antenna to remove azimuth and elevation translation errors between the transponder antenna centerline and the collision avoidance radar antenna centerline. The second laser beam (216) is aligned when transmitted from the automobile onto a second piece of reflective material attached to the alignment fixture (210). The transponder (200) is then used to zero an angle (&agr;) between the electrical boresite of the collision avoidance radar antenna and the boresite of the transponder antenna. The angle (&agr;) is set to zero by adjusting the automobile collision avoidance radar antenna until a processor in the collision avoidance radar indicates the angle a is zero.
Abstract:
A calibration technique for a vector network analyzer (VNA) enabling calibration standards to be included internal to the VNA. To calibrate the VNA utilizing the internal calibration standards, error terms a, b and c of two two-port error boxes E are defined between the measurement ports and the reflectometer of the VNA wherein a=-det(E), b=e00 and c=e10. Error terms a, b and c are determined by measuring external calibration standards with known reflection coefficients connected directly to the measurement ports. Reflection coefficients for internal calibration standards are then determined using the error terms a, b and c to enable future automatic calibrations. To measure S-parameters of an arbitrary device under test (DUT), one embodiment of the present invention uses the Ferrero technique to measure a reciprocal thru with estimated S.sub.21 characteristics connected between ports A and B to determine an additional error term .alpha. for the error boxes E, where .alpha.=e01.sub.A /e.sub.01B.
Abstract:
An asymmetrical coupling circuit for use in a network analyzer is provided with a pair of couplers coupled to the input and output ports of a device under test (DUT) for improving the dynamic range of forward and reverse transmission measurements. The through-arms of the couplers are used to connect the input and output ports of the DUT to the reference signal source and measuring circuit to thereby eliminate the attenuation caused by feeding a signal through the coupling arm of the coupler as occurs in symmetrical coupler arrangements.
Abstract:
A test system is provided operating in the 76-77 GHz range for testing components of a collision avoidance radar system. The system uses a Scorpion vector network analyzer (VNA) having an internal stimulus source synthesizer operating over a narrow 3-6 GHz range. The source signal from the Scorpion VNA is up-converted in a test module to a 75-78 GHz signal, without using a non-linear multiplier between the Scorpion VNA source and a device under test (DUT). A 72 GHz. local oscillator (LO) signal is provided for up-conversion as well as down-conversion using a dielectric resonator oscillator (DRO) phase-locked to a crystal oscillator of the Scorpion VNA. The DRO is included internal,to the test module. Fundamental up-conversion and down-conversion is provided in the test system so that significant conversion losses do not occur, as when higher order harmonics are used.