A multi-slit type spectrometer includes a light diffracter which diffracts an incident light according to wavelengths; an optical shutter array member including a plurality of optical shutter elements arranged in correspondence with wavelength bands diffracted by the light diffracter, operable to transmit an incident ray according to an applied voltage, and made of PLZT. A zone of a given number of adjacent optical shutter elements is applied with a voltage corresponding to the wavelength bands ...

A twist vibrator includes a piezoelectric bimorph which vibrates at a fist end thereof in a twisting direction, and a rigid block connected to a second end of the bimorph. The rigid block restrains the second end from being deformed.

An actuator including a unitary ceramic element capable of bending in resse to an applied voltage. The ceramic has a first region of lower resistivity in contact with a second region of higher resistivity. There is no seam where said regions contact each other. The first region contains an additive in an amount needed to reduce resistivity thereof relative to said second region. The second region is devoid of additive or contains a different additive that raises resistivity thereof or contains t...

In a video tape recorder of the color under recording type, in which a low frequency band converted carrier chrominance signal is recorded together with an FM luminance signal, another FM modulator is provided for modulating a wide band chrominance signal. An additional head records the FM chrominance signal on at least a part of a track on which video signal has been recorded in the color under recording. In reproduction, it is checked whether the FM chrominance signal is reproduced or not for ...

A multi-slit type spectrometer includes a diffractor by which an incident light is diffracted according to wavelengths; an optical shutter array member including a plurality of optical shutter elements arranged in correspondence with wavelength bands diffracted by the diffractor, operable to transmit an incident ray according to an applied voltage, and made of PLZT. Each optical shutter element is applied with a voltage corresponding to the band of the ray incident upon the optical shutter eleme...

A transimpedance amplifier circuit includes a first amplifier with an input, an output and a first transconductance. A second amplifier has an input that communicates with the output of the first amplifier, an output and a second transconductance. A first resistance has one end that communicates with the input of the first amplifier. An inverter has an input that communicates with the output of the second amplifier and an output that communicates with an opposite end of the first resistance. A s...

In a high frequency power amplifier circuit in which bias voltages are applied to the transistors for amplification by current mirroring, this invention enables preventing waveform distortion near the peak output power level by allowing sufficient idle currents to flow through the transistors for amplification, while enhancing the power efficiency in a low output power region. The power amplifier includes a detection circuit comprising a transistor for detection which receives the AC component o...

A plurality of variable gain amplifier stages are coupled by an attenuation circuit that receives a voltage input to be amplified. A control circuit activates each of the variable gain amplifier stages in a seamless manner in accordance with a control signal applied to a voltage control node, while maintaining no more than one of the stages active at any time. Fractions of the reference signal voltage level are set to define boundaries between control voltage level ranges of the amplifier stages...

Principles of the present invention provide improved amplifiers such as low-noise amplifiers. While such amplifiers may be suitable in many applications, such amplifiers may provide improved noise, gain and stability performance at millimeter-wave frequencies. In a first aspect of the invention, an amplifier includes a first amplifying stage including a common-base transistor, and a second amplifying stage, coupled to the first amplifying stage, including a cascode transistor pair. The amplifier...

An amplifier system is provided for amplifying an input signal to provide an amplified output signal, amplifying an amplified input signal to provide a further amplified output signal, and phase delay compensating variations of the amplifications of the amplified output signal and the further amplified output signal for providing the further amplified output signal with substantially linear amplification under a variable load.