Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Corporation

Mitsubishi Denki Kabushiki

Kiyoharu Seino

Tadashi Takagi

Fumio Takeda

Yukio Ikeda

Tomohiko Ono

Gen Toyoshima

Haruzo Hirose

Satoshi Ogura

Masahiko Hunada

Akihiro Kamikokura

Since the loss of the conventional microwave device is large, when this device is applied to the microwave component, there are problems; for example, a low-noise amplifier, the noise figure is degraded, and when applied to a high-output amplifier, output and efficiency may be decreased. In particular, in the high-output amplifier of over 100 W class, heat generation at a capacitor which forms the microwave device increases, which causes a problem that the reliability of the microwave device may be decreased. A structure is formed to include a capacitor loaded between two high impedance lines the length of which has &#xbc; wavelength in the desired frequency band and the characteristic impedance is higher than 50&#x3a9;.

Microwave device, high-frequency device, and high-frequency equipment

A phase compensation circuit includes two first inductive elements connected in series with a main line through which a signal is passed, a series circuit consisting of a capacitor and a variable capacity element which are provided between a connecting point between the first inductive elements and ground, a second inductive element connected in parallel with the series circuit, and a choke circuit connected between the capacitor and the variable capacity element of the series circuit.

Phase compensation circuit, frequency converter device and active phased array antenna

A small-sized distortion compensation circuit is disclosed. In a semi-conductor element having three terminals, its gate is used as an input terminal. One of the drain and source is used as an output terminal, and the other is grounded. This structure does not need a conventionally used circuit comprising a complicated combination of distributors, couplers and attenuators, enabling the circuit to be smaller.

Distortion compensation circuit

A small-sized, high-efficiency semiconductor amplifier exhibits a satisfactory efficiency characteristic over a wide band and a low output level for secondary and tertiary higher harmonics. The semiconductor amplifier is equipped with an output circuit which is composed of a parallel resonance circuit for the secondary higher harmonic of the fundamental-operation frequency, a first connection line, a second connection line, and an open-end line having a length corresponding to approximately 1/4 of the wavelength of the tertiary higher harmonic, the drain terminal of FETs leading to the output circuit being connected to one end of the parallel resonance circuit through the first connection line, an open point being formed at one end of the parallel resonance circuit, the other end of the parallel resonance circuit for the secondary higher harmonic being connected to the open-end line having a length corresponding to approximately 1/4 of the wavelength of the tertiary higher harmonic through the second connection line, the length and width of the first connection line being adjusted to determine the secondary-higher-harmonic load-reflection coefficient of the FETs as seen from the drain thereof to such a value as will maximize the efficiency of the amplifier, the length and width of the second connection line being appropriately adjusted so as to adjust the impedance matching conditions with respect to the fundamental wave.

Semiconductor amplifier

A distributed FET amplifier comprising an array of FET elements each having a gate terminal, a drain terminal and a source terminal. The gate terminals of the adjacent FET elements are connected by a first inductor, and the drain terminals of the adjacent FET elements are connected by a second inductor. Between the source terminals of each of the FET elements and the ground is connected a parallel circuit comprising a capacitor having a capacitance greater than the gate-source capacitance of the FET element and an impedance element connected in parallel to the capacitor for grounding the direct current. A bias voltage supply circuit for supplying a bias voltage to such as distributed amplifier is also disclosed.

Distributed fet amplifier and bias voltage supply circuit therefor

A microwave power combining FET amplifier includes T-type input and output branch circuits 13, 14 for power splitting and combining, and interstage matching circuits 6a, 6b laterally connected at their mid-points a, b by a resistance circuit 15 which absorbs odd propagation mode waves reflected back from the output combiner due to non-uniformities between the post-stage FETs 4a, 4b.

Microwave power combining FET amplifier

A power distribution circuit having two Wilkinson type bi-distribution circuits each of which halves and then distributes its input and formed of a microstrip on a dielectric substrate or a semiconductor substrate. The input terminals of the two Wilkinson type bi-distribution circuits are connected, while substantially middle parts of resistances used as isolation resistances of the respective Wilkinson type bi-distribution circuits are connected by a metallic thin wire.

Growing community of inventors

Tokyo, Japan

Kiyoharu Seino