Murata Manufacturing Co., Ltd.

Masayuki Atokawa

Yasuo Yamada

Kikuo Tsunoda

Hirofumi Miyamoto

Hajime Suemasa

Takayoshi Yui

Nobuyoshi Honda

Hideyuki Kato

Hitoshi Tada

Takahiro Okada

Kunihiro Komaki

Tsuyoshi Mukai

Masahiro Izawa

Toshihiro Yamamoto

Yuji Kaminishi

Kyoji Matsunaga

This disclosure provides an antenna and a wireless communication device that includes the antenna in which a high-order mode can be controlled while maintaining good radiation characteristics in both the fundamental mode and high-order mode. The antenna has a radiation electrode provided on a surface of a dielectric substrate and a branch electrode portion that branches from the radiation electrode portion at a branch point near the feeding port toward a vicinity of a position of the radiation electrode at which a maximum voltage of a high-order mode is generated.

Antenna and wireless communication device

A dielectric filter having a dielectric block disposed on a mount board. The dielectric block includes inner conductor holes having open ends on the front surface of the dielectric block. Input/output electrodes are disposed on the undersurface of the dielectric block. Each of the input/output electrodes extends from the boundary between a side surface and the undersurface of the dielectric block to the boundary between the front surface and the undersurface of the dielectric block. An outer conductor includes undersurface electrode corner portions and an undersurface electrode main portion. Each of the undersurface electrode corner portions is disposed at a corner formed by the front surface and one of the side surfaces of the dielectric block.

Dielectric filter having a dielectric block with input/output electrodes of a bent shape at corner portions of the block

A dielectric filter having inner-conductor holes penetrating through a dielectric block from a first surface to a second surface thereof. An outer conductor and input/output electrodes are formed on an outer surface of the dielectric block. A side of each of the input/output electrodes facing the first surface is substantially in parallel to the first surface, and an intersection of a side facing the second surface and a side facing a sixth surface is tapered. With such a configuration, an attenuation characteristic at an attenuation band is improved by making the attenuation characteristic less likely to receive an influence of a TE mode.

Dielectric filter having tapered input/output electrodes

A dielectric filter with an ultra hetero-axial structure is provided with open end-face electrodes. By increasing the capacitance between each open end-face electrode and an external conductor greater than that generated between the open end-face electrodes adjacent to each other, the inductive coupling between two resonators due to neighboring resonator holes is increased.

Dielectric filter, dielectric duplexer, and communication apparatus

A filter assembly includes a transmission filter, a reception filter, a change-over switch, and phase circuits. The transmission filter has first and second ends electrically connected to a first antenna terminal and a transmission terminal, respectively. The reception filter has a first end electrically connected to a second antenna terminal via the change-over switch, and a second end electrically connected to a reception terminal. A main antenna is connected to the first antenna terminal, and a diversity antenna is connected to the second antenna terminal. The change-over switch performs switching control to connect the reception filter to one of the first and second antenna terminals. Thus, the filters utilize a fixed number of resonators regardless of switching control of the change-over switch, thereby achieving optimum filter characteristics.

Filter assembly and communication apparatus

A shared-antenna device having a transmission circuit electrically connected between a transmission terminal and an antenna terminal, and a reception circuit electrically connected between a reception terminal and the antenna terminal. The transmission circuit is a variable-frequency band-stop filter circuit and the reception circuit is a variable-frequency bandpass filter circuit. Control-voltage supplying resistors are connected to the PIN diodes such that the DC voltages for individually controlling the PIN diodes are applied to the PIN diodes via only the resistors.

Variable-frequency resonator circuit, variable-frequency filter, shared-antenna device, and communication device

A dielectric filter provided with a dielectric block including at least four resonant through holes that are adjacent to each other. A multipath slot is arranged near three adjacent through holes of the at least four resonant through holes. The multipath slot has an inner conductor formed on an inner surface thereof in order to generate a first capacitance between a first area near the open end of each of the three adjacent through holes and the inner conductor of the multipath slot. A step is formed so that a second capacitance is generated between a second area near the open end of each of two through holes of the at least four resonant through holes and an outer conductor located within the step. An attenuation peak is generated at the lower-frequency side of the passband with the multipath slot and the three adjacent through holes, and an attenuation peak is generated at the higher-frequency side of the passband with the two through holes and the outer conductor within the step.

An outer conductor, an input terminal electrode, an output terminal electrode, a voltage controllable terminal electrode, and two separated electrodes are formed on the outer face of a dielectric block. Furthermore, on the upper face of the dielectric block, PIN diodes which are voltage controllable reactance elements, and inductors for voltage-controlling the PIN diodes, and a coupling adjustment capacitor are mounted. Frequency shifting capacitors are formed by generation of electrostatic capacitances between the separated electrodes and the inner conductors of the resonance holes, respectively.

Dielectric filter, antenna sharing device, and communication device having a voltage controlled reactance element for tuning the center frequency

Provided is a high-frequency circuit apparatus and a communication apparatus whose consumption current is small and the inserting loss is small. One embodiment provides a high-frequency circuit apparatus constructed by an antenna duplexer of a frequency variable type; a first change-over switch which is electrically connected to an antenna terminal in the antenna duplexer; a second change-over switch which is electrically connected to a receiving terminal in the antenna duplexer; and a filter for reception which is electrically connected across the first and second change-over switches. As for the first and second change-over switches, a GaAs switch and a PIN diode switch, etc. are used. As for the filter for reception, a surface acoustic wave filter or monolithic ceramic LC filter, etc. is used.

High-frequency circuit apparatus and communication apparatus

A filter with which it is possible to control the relationship between a pass band and an attenuation band. In this filter, for example, a single-stage trap filter is electrically connected to a three-stage band pass filter via a coupling capacitor. The trap filter has a serial resonance section composed of a resonator and a resonance capacitor. The serial resonance section is connected in parallel to a capacitive reactance element (capacitor), and a serial circuit composed of an inductive reactance element (inductor) and a PIN diode as a switching element. The capacitive reactance element and the inductive reactance element both serve to make an admittance of the trap circuit substantially zero.

Filter, antenna duplexer, and communication apparatus incorporating the same

In a band elimination filter, a trap capacitor and a frequency control capacitor are made by using a simple capacitor plate individually provided for each respective resonance circuit.

Filter, antenna sharing device, and communication device

A frequency variable filter in which both the frequency of an attenuation pole and the attenuation bandwidth can be varied. In the frequency variable filter, two serial resonance sections composed of resonators and resonance capacitors are electrically connected to each other via a capacitor. The respective resonator in each of the serial resonance sections is electrically connected in parallel with a corresponding serial circuit composed of a frequency shifting capacitor and a PIN diode. A coupling capacitor electrically connects the junctions defined respectively between the frequency shifting capacitor and the PIN diode in each of the serial circuits.

Frequency variable filter, antenna duplexer, and communication apparatus incorporating the same

A duplexer and a communication apparatus incorporating the same which are suitable for use in communication systems with wide frequency bands and narrow separations, and which can be miniaturized while having satisfactory characteristics. The duplexer has a transmission filter constituted of a variable frequency filter in which PIN diodes are connected to dielectric resonators and a reception filter constituted of two surface acoustic wave filters and a switching circuit. In the transmission filter, one of the higher and lower sides of a transmission frequency band can be selected according to a voltage applied to a first voltage control terminal. In addition, in the reception filter, one of the two surface acoustic wave filters can be selected according to a voltage applied to a second voltage control terminal.

Duplexer and communication apparatus with first and second filters, the second filter having plural switch selectable saw filters

A frequency-characteristics variable filter, a duplexer, and a communication apparatus that can be operated at reduced bias voltages that are applied to diodes provided for switching frequency characteristics without reducing the stability of frequency characteristics and without increasing the occurrence of skews. Also, the single duplexer can be used for two frequency bands. As a diode for each of resonators in a transmitting filter and the first resonator in a receiving resonator, a diode having an interterminal electrostatic capacitance in the off state smaller than that of a diode used for other resonators is used. Also, the diodes for the resonators excluding the first resonator in the receiving filter has a lower forward resistance in the on state and an Q value in the off state higher than those of other diodes.

Frequency-characteristics variable filter, duplexer, and communication apparatus

There is disclosed a duplexer comprising: a first external terminal; a second external terminal; an antenna terminal; a first frequency variable filter electrically connected between the first external terminal and the antenna terminal, and composed of at least one resonator and a reactance element electrically connected to the resonator and capable of being voltage-controlled; a second frequency variable filter electrically connected between the second external terminal and the antenna terminal, and composed of at least one resonator and a reactance element electrically connected to the resonator and capable of being voltage-controlled; the predetermined reactance element of the first frequency variable filter being in the on state when the reactance element of the second frequency variable filter is in the on state.

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Kanazawa, Japan

Masayuki Atokawa