Murata Manufacturing Co., Ltd.

Norihiro Tanaka

Shin Abe

Jun Hattori

Toru Kurisu

Hiroyuki Kubo

Hidekazu Sasai

Masamichi Ando

Masamichi Andoh

First and second transmission paths are provided between a first port to which an antenna is connected and a second port to which a transceiving circuit is connected. First to fourth reception filters, an amplifier circuit, and first to fourth hybrid circuits are provided on the first transmission path. A reception signal from the antenna is transmitted from the first port to the second port via the first hybrid circuit, the first and second reception filters, the second hybrid circuit, the amplifier circuit, the third hybrid circuit, the third and fourth reception filters, and the fourth hybrid circuit in this order. This reception signal does not return to the amplifier circuit, whereby the reception signal is prevented from oscillating due to positive feedback.

Transceiving filter and communication device

The measurement and adjustment of characteristics of a filter alone are performed using a connector adapter, in which a pin of the filter becomes a central conductor of the adapter. The filter after the adjustment and a device which is not adjusted are assembled, such that the filter and the device are connected by connecting the pin provided in the filter and a transmission line provided in the device. Accordingly, the time for adjustment is shortened and the adjustment for obtaining the desired characteristics of the filter module are made easy.

Manufacturing method for filter module

A dielectric resonator device comprising resonators small in size, having plural stages, and a dielectric resonator device with a high Qo, in a multimode are provided. A substantially parallelepiped-shaped dielectric core to resonate in plural modes such as TM &dgr;-x, -y, -z, TE &dgr;-x, -y, -z, and so forth is disposed in the center of a substantially parallelepiped-shaped cavity. These plural resonance modes are utilized.

Multimode dielectric resonator device, dielectric filter, composite dielectric filter, synthesizer, distributor, and communication device

A dielectric filter, a composite dielectric filter, a dielectric duplexer, a dielectric diplexer, and a communication apparatus, in which isolation between adjacent dielectric filters can be obtained, and deterioration of filter characteristics can thereby be prevented. A plurality of dielectric resonators formed by disposing dielectric cores in cavities, and coupling loops for coupling to predetermined resonance modes of the dielectric resonators, are combined to form a dielectric filter. The dielectric resonators and the coupling loops are arranged in such a manner that when the dielectric resonators of the dielectric filters are close to each other, the directions of the coupling portions of the adjacent coupling loops are substantially vertical to each other.

Dielectric filter, composite dielectric filter, dielectric duplexer, dielectric diplexer, and communication apparatus incorporating the same

A resonator includes a conductive casing provided with a threaded screw hole, a screw at least partially inserted into the casing, and a fixing member fixing the screw and having a threaded screw hole. In the resonator, the linear expansivity of the casing and the linear expansivity of the fixing member, and preferably also that of the screw, are substantially equal.

Resonator, filter, duplexer, and communication apparatus

A multimode dielectric resonator device is provided in which a dielectric core can be easily disposed in a cavity, a dielectric resonator device comprising resonators in plural stages can be obtained, and the Q is maintained at a high value. Dielectric cores to resonate in plural modes such as TM &dgr;&minus;(x&minus;z), TE &dgr;&minus;y, TM &dgr;&minus;(x&plus;z) or the like are supported substantially in the center of a cavity by means of a support in the state that the cores are substantially separated from the inner walls of the cavity at a predetermined interval, respectively.

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Nagaokakyo, Japan

Norihiro Tanaka