Taiyo Yuden Co., Ltd.

Takeshi Kosaka

Hisahiro Yasuda

Makoto Inoue

Masao Igarashi

Kenji Takei

Kenji Yoshimori

Kazuhisa Sato

Hideyuki Sekine

A balanced filter suitable for a reduction of the filter size. The balanced filter comprises strip-line resonators (SL, SL) constituting resonance electrodes coupled to an unbalanced terminal, strip-line resonators (SL, SL) coupled directly to balanced side terminals and strip-line resonators (SL, SL) coupled to the balanced side terminals through impedance elements (Z).

Balanced filter device

A stacked dielectric band-pass filter is disclosed, which enables widening of a passband to a side of a high band of 8 GHz or more. Within a stacked dielectric block, a pair of first &#x3bb;/4 resonator electrodes that are formed on approximately the same plane, and connected to input terminals or output terminals via lead conductors respectively, two capacitance electrodes that are opposed to the first &#x3bb;/4 resonator electrodes via a dielectric respectively, and formed on approximately the same plane, a &#x3bb;/2 resonator electrode for connecting the capacitance electrodes to each other, and a pair of second &#x3bb;/4 resonator electrodes that are opposed to the capacitance electrodes via a dielectric respectively, and formed on approximately the same plane, are buried.

Stacked dielectric band-pass filter having a wider passband

A balanced filter suitable for a reduction of the filter size. The balanced filter comprises strip-line resonators (SL, SL) constituting resonance electrodes on the unbalanced side, strip-line resonators (SL, SL) disposed in adjacently opposed relation to the strip-lines on the unbalanced side and constituting resonance electrodes on the balanced side, strip-line resonators (SL, SL) disposed in adjacently opposed relation to the strip-lines on the balanced side and constituting stage constituting resonance electrodes, and impedance elements (Z) coupling the resonance electrodes on the balanced side to the stage constituting resonance electrodes.

A base band of a &#x3bb;a wave generated by a &#x3bb;a/4 resonator is used as it is, a triple wave of the &#x3bb;a wave generated by the resonator is shifted to a low frequency side, and the fundamental wave and the triple wave are complemented by a pass band, generated by a &#x3bb;b/2 resonator. Consequently, a flat pass characteristic is secured in a band from the fundamental wave to the triple wave.

Band-pass filter

Under circumstances where communication devices such as mobile phones are required to be diversified, laminate filters are required to have attenuation-band characteristics which are steep on both low-frequency and high-frequency sides. The prior-art laminate filter has the problem that an attenuation band is formed only on the low-frequency side or on the high-frequency side. A laminate filter has stripline patterns that are first, second, and third resonant elements disposed on a dielectric layer, a capacitively coupled (C-coupled) pattern disposed between the first and second stripline patterns, an inductively coupled (M-coupled) pattern disposed between the second and third stripline patterns.

Filter circuit and laminate filter

A radio frequency filter having at least two dielectric resonators in juxtaposition, each resonator including a tubular dielectric body. Formed on the dielectric body of each resonator are an inner and an outer conductors and various other conductors including a terminal conductor for connection of the filter to external circuitry. In order to assure positive isolation of the terminal conductors of both resonators from each other, the outer conductors are provided with extensions which intervene between the terminal conductors for preventing then from being capacitively coupled together.

Wave filter having two or more coaxial dielectric resonators in juxtaposition

A radio frequency filter having at least two dielectric resonators in juxtaposition, each resonator including a tubular dielectric body. Formed on the dielectric body of each resonator are an inner and an outer conductors and various other conductors including a terminal conductor for connection of the filter to external circuitry. In order to assure positive isolation of the terminal conductors of both resonators from each other, the outer conductors are provided with extensions which intervene between the terminal conductors for preventing them from being capacitively coupled together.

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Gunma, Japan

Takeshi Kosaka