Abstract: Three or more MESFETs are fabricated side by side on a semiconductor chip. A transmission line substantially identical in width with an are a within which the MESFETS are fabricated is formed in parallel with the row of MESFETs. The MESFETs are connected to the transmission line by way of a side constituting one edge of the transmission line. Further, regulation circuits are connected in shunt with the transmission line, whereby outputs are merged while being matched by means of the transmission line and the regulation circuits.

Abstract: A high frequency semiconductor integrated circuit includes a main circuit, a circuit block, a pad, and a wire. The main circuit includes an input terminal, a transistor, transmission lines, a pad, and an output terminal. The circuit block includes a passive circuit, and a capacitor. The pad is disposed close to the circuit block. The wire connects the pad to the pad included in the main circuit. In the high frequency semiconductor integrated circuit, the main circuit outputs an input signal inputted at the input terminal from the output terminal through the transistor, the transmission line, the pad and another transmission. As a result, the high frequency semiconductor integrated circuit can realize various kinds of its performances and thereby can be used to many applications.

Abstract: To eliminate variations in measurement of the chip characteristics due to an increased bonding pad area, an MMIC chip is configured as follows. A pad main portion having the same width as a main line is provided at an end of the main line that is provided on a GaAs substrate 12. A plurality of pad auxiliary portions in an island-like manner adjacent to the pad main portion on one or both sides thereof. A grounding wiring layer is provided on at least one side of the pad main portion with the pad auxiliary portion interposed in between. The pad main portion and the pad auxiliary portions secure a sufficient bonding area. The electrical characteristics are measured by bringing probes into contact with the pad main portion 16a and the grounding wiring layer(s). The electrical characteristics of the MMIC chip can be evaluated without increase in bonding pad capacitance.

Abstract: An amplifier with a temperature compensation function featuring a simple configuration wherein a high frequency signal attenuation circuit is connected to a gate terminal of an amplifying active device. The high frequency signal attenuation circuit uses the source terminal and the drain terminal of a compensating active device as input and output terminals, and the gate terminal is grounded.

Abstract: The present invention provides a high frequency amplifier circuit and a microwave integrated circuit which allow easy development of various models having different operating frequencies and other properties and improve the yield of production.The high frequency amplifier circuit of the present invention comprises a high frequency transistor and a matching circuit connected between a terminal of the transistor and an external connection terminal, whereinthe matching circuit has a variable capacitive element of which one end is connected to a terminal of the transistor and the other end is connected to the external connection terminal, and a short stub of which one end is connected to the other end of the variable capacitive element and the other end is directly grounded.

Abstract: A microwave integrated circuit includes a matching circuit for electromagnetic analysis in designing the circuit. The matching circuit is a T-junction circuit comprising distributed constant lines. Miniaturization of the microwave integrated circuit is realized while reducing the time required for electromagnetic analysis and improving design precision by using meandered distributed constant lines.