Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Corporation

Yoji Isota

Yukio Ikeda

Tadashi Takagi

Shuji Urasaki

Noriharu Suematsu

Gen Toyoshima

Yoshihiko Konishi

Makoto Matsunaga

Masataka Ohtsuka

Shintaro Nakahara

Moriyasu Miyazaki

Yoshitsugu Yamamoto

Masatake Hangai

Yukinobu Tarui

Mitsuru Mochizuki

Tamotsu Nishino

Fumio Takeda

Tomoaki Fukushima

Osami Ishida

Masaki Kohno

The present invention provides a high-frequency switch including: a first switching element connected between a first input/output terminal and a second input/output terminal; a second switching element connected between the second input/output terminal and the first switching element; a high-frequency line provided between the first input/output terminal, the first switching element, and a third input/output terminal; and a third switching element connected between the third input/output terminal, the high-frequency line, and a ground. By connecting the first switching element, the second switching element, the high-frequency line, and the third switching element, because there exists no FET through which a large current flows when a state between the first input/output terminal and the third input/output terminal is set to a transmission state which requires high power handling capability, there is no need to use an FET having a large gate width, which is effective in reducing a loss of the switch.

High-frequency switch

A planar antenna apparatus adapted to excite a small radiating element by electromagnetic coupling is provided. The antenna apparatus has a triplate line including ground conductor plates formed on the upper and lower surfaces of a dielectric substrate and a feed line sandwiched by the ground conductor plates. A coupling hole is formed through one of the ground conductor plates, and a mechanism is provided near the coupling hole for electrically interconnecting the two ground conductor plates. A radiating section coupled to the feed line through the coupling hole has one end grounded to form a short patch antenna. The short patch antenna has a size substantially half the size of a patch antenna. Also, the connecting mechanism prevents unnecessary coupling.

Antenna apparatuus using a short patch antenna

An antenna apparatus, a method of manufacturing the same, and a method of designing the same, are provided. A first dielectric layer, first dielectric film, second dielectric layer and second dielectric film are laminated on a flat metal plate in the mentioned order. A radiation element fed through a feeding line is arranged below another radiation element that is not fed through the feeding line. The feeding line forms, along its overall length, a microstrip line having the dielectric layer sandwiched by the feeding line and the flat conductive plate, resulting in no model change from the microstrip line to a triplate line or vice versa, with reduced feeding loss. The thickness of the dielectric layer is so set as to be sufficiently small compared with the used wavelength, to thereby suppress the radiation from discontinuities lying on the microstrip line constituted of the feeding line and flat conductive plate. This eliminates the need for a metal shield plate to prevent unnecessary radiation from the feeding line.

Antenna apparatus, method of manufacturing same and method of designing

A method and apparatus for controlling an antenna and a tracking antenna system using them. A rate sensor detects the angular rate of the vehicle turning. On the basis of the detected value, an error correction circuit determines the steering angle of the antenna. If it is judged from the determined angle that the vehicle is not turning or only slightly turning, a motor driving circuit suspends driving of a motor and at the same time a linear actuator locks a major gear. If it is judged that an accumulated error of a control target which is determined on the basis of the output of the rate sensor is not negligible, the error correction circuit starts a closed-loop control on the basis of a receiving signal level. In such a manner, the power consumption in the motor can be reduced.

Method and apparatus for controlling antenna and tracking antenna system

A high power field effect transistor (FET) amplifier which can provide a high gain over a wide bandwidth of a microwave range includes, on a first substrate on which a grounded-source field effect transistor is disposed, a series combination of an inductor and a capacitor connected between the gate of the FET and ground. The gate of the FET is coupled to an input impedance matching circuit disposed on a second substrate. The drain of the FET is coupled to an output impedance matching circuit disposed on a third substrate.

High power field effect transistor amplifier

A high frequency amplifier circuit comprises an amplitude characteristic correction circuit and a phase characteristic correction circuit for compensating the non-linearity of the input-output characteristics of the amplifier. The amplitude characteristic correction circuit varies the drain voltage or the collector voltage of the amplifier in accordance with the envelope level of an input signal in such a manner that the relationship between the amplitude of the output of the amplifier and the amplitude of the input signal has linearity. On the other hand, the phase characteristic correction circuit provides a quantity of phase shift to the input signal in accordance with the envelope level of the input signal, and the phase-shifted input signal is applied to the amplifier in such a manner that the phase of the output of the amplifier and that of the input signal coincide with each other.

Amplifier circuit with correction of amplitude and phase distortions

A linear amplifier includes a variable attenuator and a phase shifter for modifying the amplitude and phase of an input signal to compensate for amplitude and phase distortion caused by non-linear characteristics of a high-powered amplifier utilized in a microwave band communications system. An amplitude comparator and a phase comparator compare the amplitudes and phases of input and output signals of the linear amplifier circuit to develop control signals for controlling the operation of the variable attenuator and phase shifter. The elimination of digital signal processing circuitry allows increased speed of operation that is essential for use in the microwave bands.

Linear amplifier

An amplifier circuit suitable for use in various types of communication devices, radar systems and the like, wherein a fundamental-wave signal extracted from an input side is converted into a second order signal and the second order signal is shifted so as to be opposite in phase and equal in amplitude to a second order signal produced by an amplifier such as an FET or multistage operational amplifier. The phase shifted signal is applied to the amplifier output, whereby the second order signal produced by the amplifier can assuredly be equivalently short-circuited and the operation efficiency of the amplifier can be improved.

Amplifier circuit having second order signal cancellation

In a modulation system using an amplitude and a phase of a carrier wave as information such as a QPSK system, a modulation device modifies an input signal series to compensate the nonlinear characteristics of an amplifier located at a later stage, and provides a carrier wave modulated by the modified signal series to the amplifier. A first arithmetic circuit obtains an amplitude and a phase of an input signal by calculation. A ROM is set with correction data corresponding to the calculated amplitude so as to compensate the nonlinearity of the amplifier. A modification value generating circuit and a RAM output an amount of compensation so as to further modify the correction data according to part of an output signal from the amplifier to compensate amplifier characteristic changes due to temperature variations and the like. A second arithmetic circuit provides a signal series produced from the modified amplitude and phase to a quadrature modulator.

Modulation device with input signal modification for correction of

A directional coupler having a main line and an auxiliary line each formed within a groove formed in a dielectric plate, having good directivity and capable of tight coupling.

Growing community of inventors

Tokyo, Japan

Yoji Isota