Mitsubishi Electric Corporation

Mitsubishi Denki Kabushiki Kaisha

Tomokazu Hamada

Masatoshi Nakayama

Takashi Kawabata

Kazuhisa Yamauchi

Youichi Moritani

Yasuo Morimoto

Akimichi Hirota

Hideharu Yoshioka

Shuji Ito

Hifumi Noto

Akira Inoue

Naofumi Yoneda

Kenichi Horiguchi

Takeshi Yuasa

Satoru Ishizaka

Yasuhiro Onaka

Yoshihiro Hamamatsu

Tsuyoshi Hatate

Tohru Sogabe

To obtain a downsized dielectric filter suitable for a laminating structure, a dielectric filter is configured with use of a dielectric waveguide formed of a conductor pattern and vias in a laminating direction within a multilayer dielectric substrate, two strip lines formed in a planar direction of the multilayer dielectric substrate, and two strip line-waveguide converters each configured to perform transmission line conversion between the dielectric waveguide and each strip line. In this manner, it is possible to provide a dielectric filter for which an area to be occupied in the planar direction of the multilayer dielectric substrate is suppressed.

Dielectric filter, array antenna device

Provided is a structure configured to electrically connect multi-layer dielectric waveguides, each including a dielectric waveguide formed of conductor patterns and vias in a laminating direction of the multi-layer dielectric substrate, in which the vias for forming part of a waveguide wall of each of the dielectric waveguides are arranged in a staggered pattern in the multi-layer dielectric substrate side having choke structures formed so as to electrically connect the waveguides to each other.

First and second dielectric waveguides disposed in respective multi-layer substrates which are connected by a connection structure having choke structures therein

Provided is a low distortion amplifier which can satisfy both securement of a setting space in a vicinity of a transistor and low impedance. The low distortion amplifier includes a short stub having a leading end thereof short-circuited with a high-frequency short-circuit element and a low-frequency short-circuit element, in which the short stub is connected to a vicinity of at least one of a gate terminal and a drain terminal of the transistor, and includes a plurality of branched lines, the plurality of branched lines each having a leading end thereof short-circuited with the high-frequency short-circuit element and the low-frequency short-circuit element.

Low distortion amplifier and Doherty amplifier using low distortion amplifier

A directional coupler capable of improving a directionality of a directional coupler body including four terminals. The directional coupler includes a directional coupler body including the four terminals of an input port, an output port, a coupling port, and an isolation port; and a combiner for combining powers of an output signal of the coupling port and an output signal of the isolation port of the directional coupler body; and a directionality improving circuit for amplifying or attenuating at least one of the output signal of the coupling port and the output signal of the isolation port before outputting the same, and the combiner combines powers of the output signals amplified or attenuated by the directionality improving circuit.

Directional coupler

A linearizer changes a gain characteristic to a valley characteristic in which a gain reduces and then increases. The linearizer includes: a signal path in which an RF signal input terminal an input side bias blocking capacitor, a diode pair, including diodes having opposite polarities to each other, an output side bias blocking capacitor and an RF signal output terminal in series in the stated order; a bias circuit in which a resistor is provided between and a signal path formed between the input side bias blocking capacitor and the diode pair and a bias terminal; an RF short-circuiting capacitor whose one end is connected with the bias circuit between the bias terminal and the resistor and whose other end is grounded; and a DC feed inductor whose one end is connected with the signal path between the diode pair and the output side bias blocking capacitor and whose other end is grounded.

Linearizer

In a TDMA communication system in which a base station communicates with a plurality of subscriber stations, communication time slots used in a wireless communication are allocated/arranged while avoiding an occurrence of interference. In the case that interference () occurs in a communication time slot () of a line () through which the communication is made from a subscriber station () to a base station (), interference information is registered into an interference time slot database () of the base station (). When the communication time slots are reallocated and rearranged, a TDMA control unit of the base station () executes the communication time slot reallocation/rearrangement by referring to information registered in the interference time slot database (), so that the occurrence of interference is avoided.

TDMA radio communication system, and a base station and subscriber stations for radio communication

In a radio communication system in which multiple access is carried out between a base station and a plurality of subscriber stations by a TDMA communication method, occurrence of the interference in the R channels through which the subscriber stations (to) issue a call request to the base station () can be detected precisely, and time slot arrangement of the R channels is changed by detecting the interference to thus avoid the interference.

Interference detection method and an interference avoidance method

A TDMA radio communication method including the steps of: providing a latter part of each of super frames with an assignment information notification period which is preceded by an assignment processing period, and providing a remaining part of the each of the super frame with an assignment request collecting period; transmitting, from a terminal station to a base station, assignment request information using a plurality of frames included in the assignment request collecting period; transmitting, from the base station to the terminal station, frame structure information and assignment information over a plurality of frames included in the assignment information notification period; and carrying out, in the base station, channel assignment of a radio channel, changes of the frame structure and of the channel assignment in response to timings of the super frames. This makes it possible to solve a problem involved in a conventional TDMA radio communication system in that it is difficult for the base station to achieve reassignment of channels to a plurality of terminal stations at the same time with considering the entire terminal stations connected to the base station because the conventional system carries out channel assignment, changes of the assignment and reassignment individually to the terminal stations.

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Tokyo, Japan

Tomokazu Hamada