Fujitsu Corporation

Ichiro Abeno

Kazuhiko Kobayashi

Kazunori Yamanaka

Akihiko Akasegawa

Yoshiaki Nakano

Fumihiko Kobayashi

Hiromi Miyamoto

Kenichi Kudo

Hideki Ikuta

Yoshiharu Tozawa

Kiyokazu Sugai

In a signal cancellation method and device which can cancel input signals quickly and reliably (stably), an input signal is split into a first and second signal. The second signal is split into mutually orthogonal first and second subsignals which are recombined after the respective amplitudes thereof have been adjusted, The first signal is canceled by the third signal thereby obtained. The orthogonal subsignals can undergo amplitude adjustment independently, and the third signal obtained by recombining the subsignals after adjustment can become a cancellation signal having a really selected phase and amplitude over the first through fourth quadrants of the vector plane.

Signal canceling method and device

Heat insulation chamber, thermostatic chamber and cryostat

Disclosed are a filter apparatus for use in a radio apparatus for multiplex radio communication used when a signal is branched, a jig for arranging dielectrics of the filter apparatus for use in a radio apparatus and a method for arranging dielectrics of the filter apparatus for use in a radio apparatus using the jig. A filter apparatus for use in a radio apparatus has a pair of dielectric filters having different frequency characteristics, which are connected to a common circulator, thereby reducing the number of the circulators to realize a reduction of size and a low cost of the radio apparatus and improvement of accuracy in communication.

Filter apparatus with circulator for use in radio apparatus transmitting

A phase modulator having a Gilbert cell mixer can be used in frequency ranges from a microwave frequency band of several GHz to a millimeter wave band of several 10 GHz. Two output signals Vout1, Vout2 from the Gilbert cell mixer are supplied to balanced input terminals of a balanced-to-unbalanced converter, which produces a phase-modulated output signal Vout from an unbalanced output terminal thereof. Even when a differential amplifier comprising FETs Q1, Q3 and a differential amplifier comprising FETs Q2, Q4 do not operate symmetrically, the phase modulator generates phase-modulated output signals that have the same amplitude as each other and are in opposite phase to each other. With the Gilbert cell mixer comprising FETs, the phase modulator can be used in the frequency ranges described above. If the balanced-to-unbalanced converter is in the form of a planar circuit, then the phase modulator may be implemented by an MMIC.

Gilbert cell phase modulator having two outputs combined in a balun

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Nishinasuno, Japan

Ichiro Abeno