Sony Corporation

Takahiro Ohgihara

Yoshikazu Murakami

Hiroyuki Nakano

Yasuyuki Mizunuma

Itaru Maekawa

Kuninobu Tanaka

Kanako Niikura

Seigo Ito

Hidetoshi Kawasaki

Tsutomu Okamoto

Tomikazu Watanabe

A transistor-bias voltage stabilizing circuit comprises a current saturating resistor connected in series to the output of an FET, the gate bias voltage of which is to be stabilized and a capacitor connected in parallel to the current saturating resistor. The transistor-bias voltage stabilizing circuit may comprise a voltage detecting circuit and a negative-feedback circuit connected between the input and output of an FET, the gate bias voltage of which is to be stabilized.

Bias circuit

A monolithic microwave semiconductor integrated circuit including a bias stabilizing circuit of a current mirror type formed of a bias control transistor formed of an enhancement mode compound semiconductor field effect transistor and a biased transistor formed of an enhancement mode compound semiconductor field effect transistor.

Monolithic microwave integrated circuit apparatus

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 ferrimagnetic resonator is disclosed which is stabilized upon temperature deviation and operable over a wide frequency range. The resonator comprises a ferrimagnetic thin film resonance element, a temperature detector for the resonance element a bias magnetic field generating coil, a compensation coil and a compensation circuit. The compensation circuit has a pre-coded compensation data upon operation temperature range and generates a compensation signal in response a detected temperature of the resonance element. The compensation signal is then fed to the compensation coil to generate an additional magnetic field to the resonance element thus the resonance frequency of the resonance element is stabilized upon temperature.

Growing community of inventors

Kanagawa, Japan

Takahiro Ohgihara