Mitsubishi Denki Kabushiki Kaisha

Kouji Murai

Kenji Yoshida

Koichiro Misu

Shusou Wadaka

Tsutomu Nagatsuka

Kenya Hashimoto

Koji Ibata

Masatsune Yamaguchi

Tatsuya Ohmori

Kenji Itoh

Masao Koshinaka

Kousaku Yamagata

Isao Murase

Filter circuitry is provided with a series element and a parallel element. The filter circuitry transmits signals that fall within a certain passband and attenuates signals that don't fall within the certain passband. The series element is comprised of a resonance element having antiresonance characteristics, and the parallel element is comprised of a series circuit including an inductor and a capacitor.

Filter circuit with series and parallel elements

There is disclosed an acoustic wave apparatus, constructed in such a manner that a surface rotated in the range of 34&deg; to 41&deg; from a crystal Y axis around the crystal X axis of lithium tantalate is set as the surface of a substrate, a standardized electrode thickness (h/&lgr;) obtained by standardizing a thickness h of an electrode finger constituting at least a part of an interdigital transducer by a wavelength &lgr; of a surface acoustic wave is set to the range of 0.01 to 0.05, and a duty ratio (w/p) of the electrode finger decided based on a width w and an arraying cycle p of the electrode finger is set to the value ranging from 0.6 to just below 1.0.

Elastic wave device

In an elastic wave device, an electrode, which is formed in a comb-like shape and is made of conductive material having a prescribed thickness, is arranged on a substrate of a piezo-electric element containing lithium niobate as a main component. Also, in this elastic wave device, a surface of the substrate is set to a plane which is obtained by rotating a plane perpendicular to a crystal Y-axis of the lithium niobate by an angle ranging from 55 degrees to 57 degrees around a crystal x-axis of the lithium niobate, and a duty ratio (a width w of an electrode finger/an arrangement interval p of a pair of electrode fingers) of each of a plurality of electrode fingers composing the electrode is equal to or higher than 0.4 and is lower than 1.0.

Growing community of inventors

Tokyo, Japan

Kouji Murai