U.S. Philips Corporation

Wolfram Schilz

Burkhard Schiek

Wolfgang Meyer

Eckhard Schroder

Manfred Rahlff

Klaus Gottfried Plass

Uwe Jurgen Schmidt

Rolf Jacobson

Range-dependent sensitivity of an RF doppler radar apparatus is reduced to prevent false alarms when small objects move in close proximity to the apparatus' antenna. The sensitivity is reduced by periodically FM-modulating the transmitted RF signal at a frequency corresponding to a wavelength which is at least four times the operating range of the apparatus. The reflection of the transmitted signal is mixed with the transmitted signal to produce a difference frequency signal which is sampled at instants of maximum amplitude.

Doppler radar measuring apparatus

The moisture content of an object is determined by placing the object in a field produced by a microwave applicator and measuring the dielectric properties of the applicator. The measured properties are used to derive the moisture content from known dielectric properties for the applicator without the object present, and from known moisture/dielectric properties for the specific material of the object.

Microwave method for measuring the relative moisture content of an object

Disclosed is a microwave range measuring system for determing the distance to an object by means of the phase difference between a transmitted frequency-modulated wave and the wave reflected by and received from the object. The frequency of the transmitted microwave signal is varied between two fixed frequencies f.sub.u and f.sub.o and the signal reflected by and received from the object is converted by means of a signal converter into an intermediate frequency signal from whose total phase shift the distance is derived.

Microwave range measuring system for measuring the distance of an object

A device is described for reducing the granulation during the transmission of optical information with a highly coherent radiation beam. The device includes a first objective system, a radiation-diffusing element disposed in the image plane thereof, a second objective system and a radiation refracting element of a medium whose refractive property is variable under the influence of an ultrasonic wave.

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Norderstedt, Germany

Wolfram Schilz