Ube Electronics, Ltd.

Ube Industries, Inc.

Kosuke Nishimura

Masahiko Kitajima

Hiroshi Nakamura

Keigo Nagao

Tetsuo Yamada

Masataka Fujinaga

Masahide Kondo

Chisen Hashimoto

Nobuhiro Harada

Eiji Masui

Hirofumi Kimura

A thin film piezoelectric device includes a substrate () having via holes () and a piezoelectric laminated structure () consisting of a lower electrode (), a piezoelectric film (), and an upper electrode () formed on the substrate () via an insulation layer (). A plurality of thin film piezoelectric resonators () are formed for the via holes (). The piezoelectric laminated structure () includes diaphragms () located to face the via holes () and a support area other than those. The thin film piezoelectric resonators () are electrically connected by the lower electrode (). When the straight line in the substrate plane passing through the centers () of the diaphragms () of the thin film piezoelectric resonators () has the length Dof the segment passing through the support area and the distance between the centers of the diaphragms of the thin film piezoelectric resonators () is Dthe ratio D/Dis 0.1 to 0.5. The via hole () is fabricated by the deep graving type reactive ion etching method.

Thin film piezoelectric resonator, thin film piezoelectric device, and manufacturing method thereof

A band-pass filter has a ladder-type circuit including first and second terminals whose characteristic impedances are Z, and series elements and shunt elements disposed between a first terminal and a second terminal, each of the series elements and shunt elements containing a film bulk acoustic resonator. Assuming that characteristic impedance of any one of the series elements is Zand that characteristic impedance of any one of the shunt elements is Z, the characteristic impedances Z, Z, and Zhave a relation of 1&#x3c;(Z/Z)&#x3c;2, preferably 1.3&#x3c;(Z/Z)&#x3c;1.7, and 0.5&#x3c;(Z/Z)&#x3c;1, preferably 0.6&#x3c;(Z/Z)&#x3c;0.8.

Band-pass filter using film bulk acoustic resonator

A transmission band filter () having a series of elements () each composed of a film bulk acoustic resonator and grounded shunt elements () each composed of a film bulk acoustic resonator is connected between a transmission port () and an antenna port (). A reception band filter () having a series of elements () each composed of a film bulk acoustic resonator and grounded shunt elements () each composed of a film bulk acoustic resonator is connected between a reception port () and the antenna port (). A film bulk acoustic resonator () for adjustment is connected between the antenna port () and the ground. The resonance frequency of the adjusting film bulk acoustic resonator () lies between the upper limit frequency of the transmission frequency pass band of the transmission band filter () and the lower limit frequency of the reception frequency pass band of the reception band filter (). Therefore a duplexer such that it can be a monolithic element, the power handling capability is good, the size is small, and the cost is low is provided.

Filter using film bulk acoustic resonator and transmission/reception switch

A reduced size ceramic block filter has trap holes whose center is askew from the line running through the center of the transmission poles such that the height-wise distance between its center and the center line of the transmission poles is greater than (dt&plus;d1)/2, but not greater than 3/8 of the height of the filter. The trap hole is also width-wise spaced from the next nearest transmission hole by an amount which approximates the distance between transmission holes. Due to this layout the diameter of the trap holes are reduced in order to maintain performance which is equivalent to a conventional filter whose trap holes are timely aligned with its transmission poles. The combination of reduced trap hole diameter and reduced width-wise spacing between traps and transmission holes, results in a reduced size ceramic filter.

High performance dielectric ceramic filter

A filter with an equivalent circuit that functions as well as physically larger filters without substantial drop off in performance.

Duplexer filter with offset resonator holes

A reduced size ceramic block filter has trap holes whose center is askew from the line running through the center of the transmission poles such that the height-wise distance between its center and the center line of the transmission poles is approximately between {fraction (1/8 )}and {fraction (3/8 )}of the height of the filter. The trap hole is also width-wise spaced from the next nearest transmission hole by an amount which approximates the distance between transmission holes. Due to this layout the diameter of the trap holes are reduced in order to maintain performance which is equivalent to a conventional filter whose trap holes are timely aligned with its transmission poles. The combination of reduced trap hole diameter and reduced width-wise spacing between traps and transmission holes, results in a reduced size ceramic filter.

A ceramic block filter is designed with a shunt transmission line to attenuate third harmonics. A metallized belt is printed on the top surface of the filter along its edges so that it is connected to the metallized ground of the side surfaces. Along one edge an unmetallized line is left along one edge of the filter, whose ends are grounded. The unmetallized line is designed with a length greater than one-half of the length of the metallized belt, but smaller than the length of the metallized belt. The length and width of the unmetallized line are design choices for the specific frequencies sought to be attenuated.

Dielectric ceramic filter with improved electrical characteristics in high side of filter passband

A high performance dielectric ceramic filter in a small package is designed with one or more holes positioned off of the straight-line bisecting at least two holes. This configuration allows for the elimination of at least one trap hole while maintaining a given performance characteristic for the filter. In one specific embodiment of the present invention the performance characteristics of a conventional five-hole ceramic filter is realized in a three-hole filter wherein the holes are positioned so as to form the vertices of a triangle. The width of the resulting filter is approximately 50% of the width of the conventional five-hole filter it can replace. In another embodiment the same triangular positioning may be used to realize the performance characteristics of a four-hole ceramic filter.

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Ube, Japan

Kosuke Nishimura