Murata Manufacturing Co., Ltd.

Tetsuya Kochi

Hiroaki Tanaka

Yohei Ishikawa

Fumio Kanaya

A multi-carrier measuring apparatus includes a multi-carrier generator for generating a multi-carrier signal composed of signals having plural frequencies and being orthogonal to each other, an output for inputting the multi-carrier signals to a object at the same time, and receiving the multi-carrier signals reflected on or passed through the object, a frequency characteristic measuring apparatus for measuring the characteristics for the respective frequencies of the object based on the received signal, and an indicator.

Apparatus for measuring electrical characteristics of circuit

The invention provides a small-sized low-cost spread spectrum communication device including a narrow-band interference signal elimination circuit capable of covering all the frequency band of a spread signal. A spread signal is received by an antenna and supplied to a level detection circuit via a variable amplifier and a divider. The level detection circuit controls the variable amplifier so that the spread signal is amplified to a fixed level. The signal containing a narrow-band interfering signal is then passed through a plurality of magnetostatic filters connected in series such that the saturation level thereof successively decreases, thereby limiting the narrow-band interfering signal having a level greater than the level of the spread signal in a step-by-step fashion. Thus, the narrow-band interfering signal contained in the spread signal is limited to a low level without encountering a significantly large incidental reduction in the spread signal. The narrow-band interference signal elimination circuit according to the invention may be realized in the form of a small size.

Spread spectrum communication device

A spread-spectrum communication device which substantially eliminates a narrow-band interfering signal contained in a spread signal over a wide range of frequency and which presents a good S/N ratio in a despread signal. A magnetostatic filter is used to limit the narrow-band interfering signal along with part of the spread signal. The limited spread signal and narrow-band interfering signal are despread by a matched filter. A plurality of correlation peaks, which are derived from the same symbol in the spread signal and are contained in the despread signal, are synthesized in a rake synthesizer or a post-detection integrator receiver.

Spread-spectrum communication device

A spread-spectrum communication apparatus includes a receiving antenna, amplifiers, band-pass filters, a threshold filter circuit, a despreader, a base-band demodulation circuit, and other circuit stages. The threshold filter circuit is connected in series before the despreader. The threshold filter circuit has a frequency-band width covering the band width of a spread signal and cuts interference waves at certain levels at each frequency within the frequency band. The threshold filter circuit includes a magnetostatic wave device.

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Mukou, Japan

Tetsuya Kochi