Mitsubishi Electric Corporation

Mitsubishi Denki Kabushiki Kaisha

Eiji Taniguchi

Koji Tsutsumi

Takaya Maruyama

Kenichi Maeda

Yoshinori Takahashi

Noriharu Suematsu

Akihito Hirai

Hiroyuki Joba

Takanobu Fujiwara

Takayuki Ikushima

Chiemi Sawaumi

Atsushi Kato

Tadashi Takagi

Masaomi Tsuru

Takayuki Nakai

Ryosuke Takeuchi

Tatsuya Hagiwara

There has been a problem that linearity is degraded in the conventional amplifier when the idle current is reduced in order to lower the power consumption. An amplifier of the present invention includes: a bias circuit to cause a bias current to flow; an amplifying element to amplify a signal by causing an output current corresponding to the bias current to flow; a bias current subtracting circuit to detect the signal and subtract, from the bias current, a current based on an amplitude of the signal detected; and a bias current adding circuit having an operation starting point higher than an operation starting point of the bias current subtracting circuit, and to detect the signal and add, to the bias current, a current based on an amplitude of the signal detected.

Amplifier

A high voltage rectifier includes: a power divider () dividing power of high-frequency wave RF to be rectified; a capacitor () cutting-off direct current flowing between the power divider () and a first rectifier (): and a capacitor () cutting-off direct current flowing between the power divider () and a second rectifier (). The first rectifier () generates a direct-current voltage DCby rectifying a high-frequency wave RFoutput from the power divider (), and outputs the direct-current voltage DCto one end of a load (). The second rectifier () generates a direct-current voltage DChaving a different polarity from that of the direct-current voltage DCby rectifying high-frequency wave RFoutput from the power divider (), and outputs the direct-current voltage DCto the other end of the load ().

High frequency rectifier

There are provided: a table memory to store a relation between a control code and gains of variable gain amplifiers; a gain controller to apply the gains to the variable gain amplifiers; an amplitude phase detector to detect amplitude and a phase from an output signal of the vector sum phase shifter; an amplitude phase recorder to record, when the gains are applied by the gain controller, a combination of a control code corresponding to said gains and the amplitude and the phase detected by the detector; and a table calibrator to find a phase shift characteristic of a vector summed part from records of the amplitude phase recorder and calibrate the relation between a control code and gains recorded in the table memory by using the phase shift characteristic.

Phase shift precision calibration circuitry, vector sum phase shifter, and wireless communication device

Provided is a polyphase filter, which is capable of achieving amplitude matching and phase matching while achieving a low insertion loss with a single-stage configuration. A first variable resistor and a second variable resistor have resistance values that are equal to each other, and the resistance values are set so as to correct an amplitude error between orthogonal signals of outputs of a first output terminal to a fourth output terminal. A first variable capacitor, a second variable capacitor, a third variable capacitor, and a fourth variable capacitor have capacitance values that are equal to one another, and the capacitance values are set so as to correct a phase error between the orthogonal signals of the outputs of the first output terminal to the fourth output terminal.

Polyphase filter and filter circuit

A transconductance amplifier is provided with: a cross-coupled differential pair () having one set of differential pair transistors in which signals whose polarities are opposite to each other are inputted to gates thereof, drains of one of the differential pair transistors being connected to drains of another one of the differential pair transistors, and a control circuit () comprised of logical circuits, for outputting a binary signal to the common source of each of the differential pair transistors on the basis of an output-level control signal and a polarity control signal which are inputted thereto.

Transconductance amplifier and phase shifter

An active balun circuit includes a CG transistor having a source terminal thereof connected to an input terminal and a gate terminal thereof grounded, a CS transistor having a gate terminal thereof connected to the input terminal and a source terminal thereof grounded, an asymmetrical transformer, a first output terminal, and a second output terminal. The asymmetrical transformer includes a primary coil and a secondary coil. The primary coil includes a first inductor connected to the CG transistor and a second inductor connected to the CS transistor. The secondary coil includes a third inductor associated with the first inductor and a fourth inductor associated with the second inductor. The first output terminal outputs a first signal generated at the third inductor, and the second output terminal outputs a second signal generated at the fourth inductor.

Active balun circuit and transformer

Besides a time constant circuitthat imposes a frequency limit on a wireless signal detected by a power detecting circuitat a preset time constant Ta, there is provided a time constant circuitthat imposes a frequency limit on the wireless signal at a time constant Tb greater than the time constant Ta. When the signal level of an intermittent operation signal supplied from a signal input terminalis H level or when a threshold processing circuitdecides that the level of the wireless signal is higher than a threshold Th, a logic unitsupplies a control signal that instructs starting to the power detecting circuit, time constant circuitsandand threshold processing circuitsand

Start signal generating apparatus

A frequency converter includes a transistor pair having a first transistor and a second transistor respectively having collector terminals commonly connected to each other and emitter terminals commonly connected to each other, the commonly-connected collector terminals of the transistor pair being connected to a power supply terminal by way of a first resistor, a third transistor having a collector terminal connected to the power supply terminal by way of a second resistor and an emitter terminal connected to the commonly-connected emitter terminals of the transistor pair, a third resistor having an end connected to the commonly-connected emitter terminals of the transistor pair, and another end grounded by way of a constant current source, and an output terminal connected to the commonly-connected collector terminals of the transistor pair. The frequency converter can exhibit an excellent saturation characteristic and an excellent distortion characteristic even when operating from a low voltage and/or a low current.

Frequency converter

A high frequency amplifier in which a common emitter bipolar transistor is used, and in that a constant current source and a constant voltage source are switched to apply a DC bias to a base terminal of the bipolar transistor in accordance with a power level of a high frequency signal input to the bipolar transistor or a power level of a high frequency signal output therefrom, and a frequency mixer in that a DC bias is applied to a base of at least one of a bipolar transistor for the input of a high frequency signal and a bipolar transistor for the input of a local oscillation wave by using a configuration for applying the DC bias to a base of an amplifying bipolar transistor employed in the high frequency amplifier.

Growing community of inventors

Tokyo, Japan

Eiji Taniguchi