An FM radar system of more simple construction, smaller size, lower cost and improved performance is provided in which circulators of any type in the prior art are eliminated by constructing a transceiver comprised of a transmitting part and a receiving part, each formed on a common dielectric plate and having a dedicated transmitting antenna and a dedicated receiving antenna respectively The antennas comprise planar array antennas, in contrast to the solid antennas used in prior art systems The planar array antennas are also formed on the single dielectric plate The transmitting part comprises a plurality of transmission antennas and a plurality of frequency multipliers coupled to said transmission antennas The receiving part comprises a plurality of receiving antennas which are coupled to a plurality of switches through a plurality of mixers, frequency multipliers, and low noise amplifiers

FM radar system

A modulation signal generating section produces a modulation signal for controlling an oscillation frequency of a voltage-controlled oscillator. The modulation signal generating section comprises a triangular wave oscillator producing a linear modulation component of a triangular waveform which varies the modulation frequency linearly, a sine wave oscillator producing a cyclic modulation component of a sine waveform which varies the modulation frequency cyclically, and a signal adder producing the modulation signal by adding the linear modulation component and the cyclic modulation component. A transmitting signal frequency modulated by the modulation signal is mixed with a received signal and produces a beat signal comprising a fundamental wave component of a beat frequency and harmonic components.

Radar system installable in an automotive vehicle for detecting a target object

A method and a device for sensing and analyzing an imminent collision of a motor vehicle with an obstacle. Using an FMCW radar method, obstacles are detected in the form of a spectral line. Via a proper filtering, time profiles of amplitude values of the spectral lines are produced and recorded. By comparing one actively recorded time profile to stored characteristic profiles, a lateral offset y between the motor vehicle and the obstacle is determined. Alternatively or in combination, the lateral offset can also be determined on the basis of characteristic profiles of relative velocity values.

Method and device for sensing an imminent or possible collision

The invention relates to an electromagnetic proximity fuse operating with transmission of an electromagnetic HF-wave and reception of a reflected wave received after reflection against an object, which reflected wave is combined with the transmitted one for generating a signal of doppler frequency (f a ) or so called doppler signal, which is used to initiate an ignition circuit. According to the invention the said doppler signal is led to an analogue divider (12) together with a delayed version of the said doppler signal. The analogue divider (12) delivers an output signal of doppler frequency (f d ), the amplitude of which is equal to the quotient between the prevailing value (U 1 ) of the doppler signal and the value of the doppler signal a predetermined time interval previously (U 2 ). This quotient signal of dopper frequency is led to a filter (15), which at least approximately has a frequency characteristic equal to 1/(f o + f), where f o is a system parameter and f is the input frequency, i.e. in the present case equal to the doppler frequency (f d ). The output signal from the filter (15) is finally led to an ignition circuit (17) via a threshold circuit (6) having a fixed threshold in order to initiate the ignition circuit (17), when the output signal from the filter exceeds a given value. Hereby the ignition circuit (17) will be triggered at a constant distance from the reflecting object independently of such unknown variables as the approaching speed, the reflection factor of the object and the gain factor of the HF-system.

An electromagnetic proximity fuse

An anticipatory object detention system includes a transducer device (18) for transmitting a modulated carrier signal and receiving the reflected modulated carrier signal from an object; a detection device (22) for detecting a plurality of Doppler shifted harmonic components from the reflected modulated carrier signal; a range determining device (24) responsive to the amplitude of at leastwo of the harmonic components for determining the instantaneous range of the object; a velocity measurement device (26), responsive to the frequency of at least one of the harmonic components, for determining the relative, instantaneous velocity of the object.

Anticipatory collision sensor system

An improvement of a method for measuring distance to target using transmitted and reflected frequency-modulated continuous waves is provided. A low frequency wave produced by mixing a transmitted wave and a wave reflected from the target is separated into frequency components such as a Doppler signal component, a fundamental wave component and its harmonic components. Then, Doppler signals are obtained from the fundamental wave and harmonic components. The ratio in intensity between at least two Doppler signals is calculated to measure the distance to the target. Since the phase of Doppler signal is reversed depending upon whether the target is moving toward or away from the distance measuring apparatus, the direction of the relative movement between the target and the apparatus may be detected. Furthermore, the relative speed between the target and the distance measuring apparatus may be detected from the frequency of each Doppler signal. When the ratio of the distance to the target to the relative speed reaches a predetermined value, a command signal to actuate a device is produced.

Yamanaka Teruo

Papers

Method and apparatus for measuring distance to target using frequency-modulated continuous waves

Verfahren und vorrichtung zur messung der entfernung zu einem ziel mit frequenzmodulierten, kontinuierlichen wellen