Murata Manufacturing Co., Ltd.

Kikuo Tsunoda

Shigeji Arakawa

Youhei Ishikawa

Toshiro Hiratsuka

Masayuki Atokawa

Yasuo Yamada

Hirofumi Miyamoto

Hajime Suemasa

Hirotsugu Abe

Yasunori Takei

Hideyuki Kato

Masamichi Ando

Hiromitsu Ito

Hitoshi Tada

Haruo Matsumoto

Sadao Yamashita

Motoharu Hiroshima

Jun Toda

Shohachi Nishijima

Hiromi Ogura

Kazuyoshi Miyawaki

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

A plurality of cylindrical inner conductor portions having different diameters are connected with each other to form an inner conductor. The inner conductor portions include high-impedance portions and low-impedance portions. The inner conductor is formed within an outer conductor with a nonuniform inner diameter. The inner conductor is formed so that the axial length of some of the inner conductor portions forming the high-impedance portions is smaller than the axial length of the other inner conductor portions forming the high-impedance portions, and the diameter of the inner conductor portions forming the high-impedance portions is greater than a predetermined minimum diameter.

Low-pass filter

An inner conductor comprising high impedance portions and low impedance portions alternately connected to each other is disposed in the center of an outer conductor having a substantially square cross-section. Two holes are formed in one side of the outer conductor so as to extend through the wall of the outer conductor. A substantially &pgr;-shaped coupling line comprising a main line portion and probe-connecting portions is formed on the surface of a dielectric substrate. Probes made of conductor rods are connected at the ends, respectively. A resistor is provided at one end of the main line of the coupling line. The other end of the main line functions as an output terminal, and can be connected to an external circuit. The probes are inserted through the holes. The dielectric substrate is disposed inside of the outer conductor at predetermined positions.

Filter having directional coupler and communication device

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

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 dielectric filter includes a dielectric block and an outer conductor on outer surfaces of the dielectric block. The dielectric block has holes having inner conductors, with gaps provided by sections devoid of inner conductor. A section devoid of outer conductor is formed on an edge portion around a stray surface of the dielectric block. Accordingly, a TE-mode resonance having one quarter the wavelength in the axial length direction of the dielectric block is generated. The TE-mode resonance and a TEM-mode resonance are combined to form an attenuation pole.

Dielectric filter providing TEM- and TE-mode resonators and communicaton device using the same

A dielectric filter and a dielectric duplexer adapted to two frequency bands formed by using a single component are disclose, in addition to a communication apparatus using the same. In this case, since a dielectric block used as the single component can be easily molded and grasped, production efficiency can be enhanced. The dielectric duplexer adaptable to two frequency bands is formed by disposing inner-conductor-formed holes acting as &lgr;/2 resonators and &lgr;/4 resonators in the single dielectric block.

Dielectric filter, dielectric duplexer, and communication apparatus using the same

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.

Voltage-controlled duplexer and communication apparatus

The invention provides a filtering device of the transmission-reception switched type which can be constructed in a form with a reduced size at a low cost without having to use circuit elements such as a capacitor, a coil, and a transmission line forming a phase shift circuit which are not essential to the filtering device. Inner conductors serving as distributed-parameter resonance lines are formed in a dielectric block. There is provided a coupling line coupled with particular inner conductors. The open-circuited ends of these particular inner conductors are connected to an outer conductor via corresponding diode switches so that transmission and reception filters are switched from each other when either diode switch is selectively turned on.

Filtering device comprising filters, each having a resonance line, a coupling element coupled to said resonance line, and a switch for short-circuiting said resonance line

A conducting film is formed on a dielectric block in a dielectric waveguide resonator, and a through-hole is formed in the dielectric block. The unloaded Q is set by selecting the outside dimensions of the dielectric block. The resonance frequency is set by selecting the size and location of the through-hole as well as the outside dimensions of the dielectric block. A terminal electrode is formed on the outer surface of the dielectric block, for example at an end surface. A coupling hole is formed in the dielectric block and a coupling electrode is formed on the inner surface of the coupling hole. One end of the coupling electrode is connected to the terminal electrode and the other end of the coupling electrode may be connected to the conducting film formed on the outer surface of the dielectric block, for example at a side surface. The coupling electrode is non-linear, preferably L-shaped. The above structure allows an increase in the degree of freedom in the design of the characteristics including the resonance frequency and unloaded Q of the dielectric waveguide resonator. The invention also provides a dielectric waveguide filter with a simple coupling mechanism whereby it is possible to couple to an external circuit without having to use an additional member and without electromagnetic leakage.

Dielectric waveguide resonator, dielectric waveguide filter, and method of adjusting the characteristics thereof

A conducting film is formed on a dielectric block in a dielectric waveguide resonator, and a through-hole is formed in the dielectric block. The unloaded Q is set by selecting the outside dimensions of the dielectric block. The resonance frequency is set by selecting the size and location of the through-hole as well as the outside dimensions of the dielectric block. A terminal electrode is formed on a side surface of the dielectric block. A coupling hole is formed in the dielectric block and a coupling electrode is formed on the inner surface of the coupling hole. One end of the coupling electrode is connected to the terminal electrode and the coupling electrode extends toward the conducting film formed on the opposite side surface and one end surface of the dielectric block. The above structure allows an increase in the degree of freedom in the design of the characteristics including the resonance frequency and unloaded Q of the dielectric waveguide resonator. The invention also provides a dielectric waveguide filter with a simple coupling mechanism whereby it is possible to couple to an external circuit without having to use an additional member and without electromagnetic leakage.

An antenna-duplexer and communication apparatus in which relative phase distortion of transmitted waves and intrusive waves is low, and which are small-scale. An antenna-duplexer comprises a transmission side circuit, electrically connected between a transmission terminal and an antenna terminal, and a reception side circuit, electrically connected between a reception terminal and the antenna terminal. Two PIN diodes, which are connected in series, are connected only to a resonator of the transmission side circuit which is electrically connected closest to the antenna terminal, and a voltage control terminal is connected to the anodes of the PIN diodes, thereby dividing the high-frequency voltage. One PIN diode is connected to each of the other resonators.

Antenna-duplexer and communication apparatus

A dielectric duplexer or multiplexer in which a conducting film is formed on a dielectric block in a dielectric waveguide resonator, and a through-hole is formed in the dielectric block. The unloaded Q is set by selecting the outside dimensions of the dielectric block. The resonance frequency is set by selecting the size and location of the through-hole as well as the outside dimensions of the dielectric block. A terminal electrode is formed on the outer surface of the dielectric block. A coupling hole is formed in the dielectric block and a coupling electrode is formed on the inner surface of the coupling hole. One end of the coupling electrode is connected to the terminal electrode and the other end of the coupling electrode is either connected to the conducting film formed on the outer surface of the dielectric block or terminated inside the dielectric block. The above structure allows an increase in the degree of freedom in the design of the characteristics including the resonance frequency and unloaded Q of the dielectric waveguide resonator. The invention also provides a dielectric waveguide filter with a simple coupling mechanism whereby it is possible to couple to an external circuit without having to use an additional member and without electromagnetic leakage.

A conducting film is formed on a dielectric block in a dielectric waveguide resonator, and a through-hole is formed in the dielectric block. The unloaded Q is set by selecting the outside dimensions of the dielectric block. The resonance frequency is set by selecting the size and location of the through-hole as well as the outside dimensions of the dielectric block. A terminal electrode is formed on the outer surface of the dielectric block. A coupling hole is formed in the dielectric block and a coupling electrode is formed on the inner surface of the coupling hole. One end of the coupling electrode is connected to the terminal electrode and the other end of the coupling electrode is either connected to the conducting film formed on the outer surface of the dielectric block or terminated inside the dielectric block. The above structure allows an increase in the degree of freedom in the design of the characteristics including the resonance frequency and unloaded Q of the dielectric waveguide resonator. The invention also provides a dielectric waveguide filter with a simple coupling mechanism whereby it is possible to couple to an external circuit without having to use an additional member and without electromagnetic leakage.

A conducting film is formed on a dielectric block in a dielectric waveguide resonator, and through-holes are formed in the dielectric block. The unloaded Q is set by selecting the outside dimensions of the dielectric block. The resonance frequency is set by selecting the size and location of the through-holes as well as the outside dimensions of the dielectric block. Terminal electrodes are formed on the outer surface of the dielectric block. Coupling electrodes are formed on the inner surfaces of the through-holes. One end of each coupling electrode is connected to the corresponding terminal electrode and the other end of the coupling electrode may be connected to the conducting film formed on the outer surface of the dielectric block. Alternatively, the other end of the coupling electrode may be partially removed to adjust the amount of coupling; or may be completely removed so as to isolate the coupling electrode from the conducting film on the outer surface. The above-described structures increase the degree of freedom in the design of the characteristics, including the resonance frequency and unloaded Q, of the dielectric waveguide resonator. The invention also provides a dielectric waveguide filter with a simple coupling mechanism whereby it is possible to couple to an external circuit without having to use an additional member and without electromagnetic leakage.

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Mishima-gun, Japan

Kikuo Tsunoda