Matsushita Electric Industrial Co., Ltd.

Hayato Akazawa

Tsugihiro Kurihara

Eiji Kobayashi

Kazutaka Iwase

Kazuaki Kimura

A detection apparatus is provided to detect the direction of arrival and the position of an emission source of radio wave with high accuracy. The apparatus comprises; a first and a second directional antenna and which rotates with a desired angle of elevation; a first and a second phase integral means and for outputting an integration of the output from an antenna; a first and second phase differential means and for outputting an difference of the outputs from an antenna; a first and a second frequency dividing means and for dividing frequency of the integral component of the output from an antenna; a first and a second differential gain control means and for controlling a gain of the differential component of the output from an antenna; a first and a third receiving means and for receiving an output of the frequency dividing means; a second and a fourth receiving means and for receiving an output of the differential gain control means; a first and a second subtraction means and for subtracting one detection signal output from the other detection signal output of each of receiving means and and receiving means and ; a first and a second calculation means and for determining a direction of arrival of radio wave based on an output from the subtraction means; and a position determining calculation means for determining the position of the emission source of the radio wave based on an output from the calculation means.

Radio direction and position finding apparatus

An object of the present invention is to provide a selective level measuring apparatus with wider dynamic range of effective value detection, compared with the range by a conventional one. The apparatus according to the present invention comprises a gain control means arranged before an effective value detection section for varying a gain by a control voltage, so that a signal level inputted into the effective value detection section may be kept to be constant level by the gain control means, and the signal level of the signal to be measured is measured and indicated through the control voltage. Performing such operations allows the selective level measuring apparatus for the effective value detection to secure a dynamic range defined by a variable quantity of the gain control means. Accordingly, the present invention provides the wider dynamic range of the effective value detection comparing with that by the conventional one.

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Yokohama, Japan

Hayato Akazawa