Fujitsu Corporation

Fuji Electrochemical Co., Ltd.

Hiroyuki Sogo

Yasuyuki Kondo

Kazuhisa Yamazaki

Atsushi Yamashita

Jun Oyama

Hideo Sugawara

Yutaka Hamada

Mitsuru Seta

Isamu Umino

Masahiko Shirota

Kenichi Kudo

Hideo Ashida

Tsudoi Kubo

Yasuo Tanishima

Zenichi Ohsawa

Haruki Nishida

Junji Konda

Shigemitsu Suzuki

Hitoshi Ishikawa

Takehiro Shimizu

Masanori Fukuda

Rikihiko Mashima

A high-frequency circuit apparatus includes two high-frequency circuits (,) mounted on a printed circuit board (,), two rows of first plated through holes (,) which connect upper and lower ground plates (,) on the upper and lower surfaces of the printed circuit board (,) and which are arrayed in a first direction so that the two high-frequency circuits (,) are disposed between the first plated through holes, and at least two columns of second plated through holes (,) which are arrayed in a second direction different from the first direction, between the two high-frequency circuits to connect the ground plates on the upper and lower surfaces of the printed circuit board, to thereby form a waveguide resonator. A variable capacitance diode can be provided to be connected to a conductor pattern which is electrically isolated from the ground plates and the ground plates so as to adjust the resonance frequency of the waveguide resonator.

High-frequency circuit apparatus

A base transceiver station in a wireless local loop system using a personal handy-phone system constituted by a plurality of cell stations, each accommodating a plurality of subscriber units, a hybrid section integrally handling signals transmitted and received by the plurality of cell stations via a single antenna, and a multiplexing/demultiplexing unit integrally handling the signals transferred between the plurality of cell stations and an existing network, thereby enabling construction of a wireless local loop system which is small in size, can expand the service area without an increase of interference with other base transceiver stations, has a good affinity with existing networks, is provided with ISDN functions, and, at the same time, provides backup against faults and improves the transmission quality and reliability.

Base transceiver station and subscriber unit in wireless local loop system using personal handy-phone system and method for operating same

A wireless base station equipment includes a transmission power controlling unit for controlling a transmission power of a transmitted signal to be transmitted to a mobile station in accordance with a status of signal reception from the mobile station and a beam tilt angle varying unit for varying a beam tilt angle of an antenna formed with respect to a horizontal plane, based on the level of transmission power control by said transmission power controlling unit.

Wireless base station equipment

In order to improve filter loss of a waveguide filter having coaxial/waveguide mode conversion parts at its ends, conductor posts bridging a space between two long sides of the waveguide are provided between the parts and the ends. The conductor posts have sufficient thickness and remain close enough to each other and to short ends of the waveguide that a partition plane including axes of the conductor posts can be regarded as an imaginary short plane. The conductor posts are located so that the partition plane is positioned at a distance .lambda./4.times.n (n=1, 3, 5 . . . ) from the coaxial/waveguide mode conversion part.

Waveguide filter with coaxial/waveguide mode conversion

A dielectric resonator with a dielectric block. The block has a plurality of resonance apertures and coupling-prevention aperture between the adjacent resonance apertures within the block. The block is entirely coated with a conductive film except a limited portion around the one end of the resonance apertures.

Dielectric filer having a decoupling aperture between coaxial resonators

A first dielectric block or blocks have a cut out portion and the cut out space is filled with a second dielectric block. A bypass pattern is formed on the second dielectric block and is capacitively coupled with two resonance elements formed on the first dielectric block or blocks. the dielectric filter is compact, and the position and intensity of attenuation poles can be freely designed and easily adjusted.

Dielectric filter with attenuation poles

A resonator element formed of a half or a quarter of dielectric cylinder contacts an electrically conductive plane via the resonator element's radially cut side which includes the axis of the cylinder, accordingly, resonates in TE.sub.01.delta. -mode. On an opposite side of the electrically conductive plane there is provided an unbalanced transmission line, for example, of a strip line type or a coaxial line type. An end of the transmission line is electromagnetically coupled via a dielectric material in the transmission line or directly with the radially cut side of the resonator element through an opening provided on the electrically conductive plane. Coupling circuit according to the present invention allows a compact overall circuit configuration.

Dielectric resonator circuit

A frequency conversion unit comprising a local oscillator, first and second mixers, first and second hybrid circuits. The mixers receive, via the first hybrid circuit, local oscillation outputs from the local oscillator, and the second hybrid circuit receives outputs from the first and second mixers, producing a frequency conversion output signal therefrom. Intermediate frequency signals used in the first and second mixers are .pi. radians out of phase with each other. The first hybrid circuit produces outputs for the first and second mixers having a predetermined phase difference of .phi..sub.1 therebetween. The second hybrid circuit receives outputs from the first and second mixers and combines them after making a phase difference of (.pi.-.phi..sub.1) therebetween.

Frequency conversion unit

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Kawasaki, Japan

Hiroyuki Sogo