Sony Corporation

Yasuyuki Mizunuma

Yoshikazu Murakami

Hiroyuki Nakano

Takahiro Ohgihara

Kanako Niikura

Tsutomu Okamoto

A selective etching method by etching a III-IV group compound semiconductor which is substantially free from Al and which is disposed adjacent to a III-IV group compound semiconductor containing Al, using a mixed gas at least containing a gas containing C and F as constituent gases and a gas containing Si and Cl as constituent gases.

Selective etching method for III-V group semiconductor material using a

In a thin film ferromagnetic resonance tuned filter is disclosed which comprises a ferrimagnetic thin films, input and output signal transmission lines respectively coupled with the ferrimagnetic thin films, and a magnetic circuit for applying a DC magnetic field to the ferrimagnetic thin films, the present invention expands the variable frequency band by forming extensions each extending from the signal transmission line so that the distance from the coupling point of the signal transmission line coupled with the corresponding ferrimagnetic thin film to the grounded end thereof is 1/10 or above and less than 1/4 the wavelength of a wave transmitted in the transmission lines at the upper limit frequency of a tuning frequency band. Further the deterioration of the isolation characteristics is suppressed by bending the extended portions not to form parallel portions to another transmission line.

Thin film ferromagnetic resonance tuned filter

A tuned oscillator utilizing a thin film ferromagnetic resonator is disclosed. The oscillator comprises an active element for oscillator and a YIG thin film resonator connected to the active element as a part of feed-back circuit for the active element. The YIG thin film resonator is applied with a bias magnetic field perpendicular to a surfce of a YIG disk which is generated by a permanent magnet for a fixed component and a coil for a variable component for the resonance frequency. The resonance frequency is stabilized by use of a PLL circuit connected to an output of the oscillator and feeding back to the coil. Since the YIG thin film tuned oscillator has a high Q value, high quality communication signal processing can be achieved. The YIG tuned oscillator is used as local oscillator for a transciever.

Tuned oscillator utilizing thin film ferromagnetic resonator

A tuned oscillator is disclosed which consists of an active element for oscillation, a ferrimagnetic resonant element connected to part of feedback of the active element, and a matching circuit connected to the active element. The matching cirucit is designed to reflect the fundamental wave produced by the ferrimagnetic resonant element and active and pass the second harmonic wave. Consequently, the magnetic circuit has its load reduced in applying a D.C. magnetic field necessary for frequency tuning to the ferrimagnetic resonance element.

Tuned oscillator

A ferromagnetic resonator is disclosed, in which perpendicular ferrimagnetic resonance of thin film YIG is utilized. The resonator comprises a ferrimagnetic YIG thin film and a microstrip line coupled to the YIG thin film operative in a bias magnetic field applied perpendicular to a major surface of the YIG thin film. The YIG thin film disk has a magnetization distribution of magnetostatic mode, and the microstrip line is designed to generate a high-frequency magnetic field distribution similar to the magnetization distribution of the uniform mode (1, 1).sub.1. In such arrangement, coupling between the high-frequency magnetic field and magnetization of high sprious mode is reduced.

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Kanagawa, Japan

Yasuyuki Mizunuma