Mitsubishi Electric Corporation

Mitsubishi Denki Kabushiki Kaisha

Kazuhisa Yamauchi

Masatoshi Nakayama

Akira Inoue

Tomokazu Hamada

Kenichi Horiguchi

Satoru Ishizaka

Hifumi Noto

Koichi Fujisaki

Atsushi Yamamoto

Koji Yamanaka

Yuji Sakai

Takashi Fujiwara

Tadashi Takagi

Kazuhiko Nakahara

Kazutomi Mori

Hidenori Yukawa

Kenji Miyasaka

Masaki Kawamura

Yasuhiro Onaka

Nobuhiro Tokumori

Yoshihiro Hamamatsu

Hiroomi Ueda

A fine-adjustment synthesizer includes a fractional phase-locked loop having a reference integer frequency divider, a phase comparator, a loop filter, a frequency variable oscillator, a mixer, a baud-pass filter, and a feedback path programmable fractional frequency divider. A coarse-adjustment synthesizer includes an integer-type phase-locked loop having a reference integer frequency divider, a phase comparator, a loop filter, a frequency variable oscillator, a band-pass filter, and a feedback path programmable integer frequency divider. An output of a reference signal source is input in parallel to both the fine-adjustment synthesizer and the coarse-adjustment synthesizer. An output of the frequency variable oscillator in the fine-adjustment synthesizer and an output of the frequency variable oscillator in the coarse-adjustment synthesizer are guided to the mixer and an output signal of the fine-adjustment synthesizer is guided to an output end.

Synthesizer

A variable frequency amplifier includes a main amplifier systemfor amplifying one of signals into which an input signal is split by a directional couplerto output the amplified signal, and an injection amplifier systemfor adjusting at least one of the amplitude and phase of the other one of the signals into which the input signal is split by the directional coupleraccording to a setting provided thereto from outside the variable frequency amplifier, and for amplifying the other signal and injecting this amplified signal into an output side of the main amplifier system

Variable frequency amplifier

Provided is a low distortion amplifier which can satisfy both securement of a setting space in a vicinity of a transistor and low impedance. The low distortion amplifier includes a short stub having a leading end thereof short-circuited with a high-frequency short-circuit element and a low-frequency short-circuit element, in which the short stub is connected to a vicinity of at least one of a gate terminal and a drain terminal of the transistor, and includes a plurality of branched lines, the plurality of branched lines each having a leading end thereof short-circuited with the high-frequency short-circuit element and the low-frequency short-circuit element.

Low distortion amplifier and Doherty amplifier using low distortion amplifier

A directional coupler capable of improving a directionality of a directional coupler body including four terminals. The directional coupler includes a directional coupler body including the four terminals of an input port, an output port, a coupling port, and an isolation port; and a combiner for combining powers of an output signal of the coupling port and an output signal of the isolation port of the directional coupler body; and a directionality improving circuit for amplifying or attenuating at least one of the output signal of the coupling port and the output signal of the isolation port before outputting the same, and the combiner combines powers of the output signals amplified or attenuated by the directionality improving circuit.

Directional coupler

Provided is a power amplification device including: a DC power supply that outputs a drain voltage; a Doherty amplifier including a carrier amplifier and a peak amplifier, which are connected in parallel, and amplifies an RF signal; a voltage control circuit that outputs a first instruction to output a low voltage when an output power is equal to or lower than a given value, and outputs a second instruction to output a high voltage when the output power is larger than the given value; and a voltage converter circuit that converts the drain voltage to a voltage lower than the drain voltage and applies the converted voltage to drain terminals of the carrier amplifier and the peak amplifier according to the first instruction, and applies the drain voltage directly to the drain terminals of the carrier amplifier and the peak amplifier according to the second instruction.

Power amplification device

When an input signal level is small, the electrical length of a phase lineand the electrical length of a phase lineare set in such a manner that the impedance seen by looking into the output side from an impedance reference pointat the output side of a carrier amplifierbecomes 2R+&#x3b1; (where R is a load resistance and &#x3b1; is positive), and the electrical length of a phase lineis set at a difference between the electrical length of the phase lineand the electrical length of the phase line

High efficiency amplifier

A linearizer changes a gain characteristic to a valley characteristic in which a gain reduces and then increases. The linearizer includes: a signal path in which an RF signal input terminal an input side bias blocking capacitor, a diode pair, including diodes having opposite polarities to each other, an output side bias blocking capacitor and an RF signal output terminal in series in the stated order; a bias circuit in which a resistor is provided between and a signal path formed between the input side bias blocking capacitor and the diode pair and a bias terminal; an RF short-circuiting capacitor whose one end is connected with the bias circuit between the bias terminal and the resistor and whose other end is grounded; and a DC feed inductor whose one end is connected with the signal path between the diode pair and the output side bias blocking capacitor and whose other end is grounded.

Linearizer

A T-type circuit having series resistors and a parallel resistor is arranged on the outside of an amplifier, a signal is amplified in the amplifier while stabilizing the signal by using the T-type circuit functioning as a stabilizing circuit, and the amplified signal is output. In this case, values of the series resistors and the parallel resistor of the T-type circuit are determined so as to set an output load impedance obtained by seeing the output side of the high-frequency amplifier from the amplifier to a value near to or slightly lower than a value of the conjugate complex impedance of an output impedance of the amplifier. Therefore, the output signal having a high output electric power and a low distortion can be obtained in the high-frequency amplifier while keeping a gain and a noise characteristic of the high-frequency amplifier.

High-frequency amplifier and high-frequency multistage amplifier

Growing community of inventors

Tokyo, Japan

Kazuhisa Yamauchi