Abstract: A first wiring layer in a circuit substrate structure is provided with a first inductor and a second inductor. A dielectric layer is provided with a first via and a second via electrically connected to the first inductor and the second inductor, respectively. A second wiring layer is provided with: abridge electrically connecting the first via and the second via; and a conductive pattern provided around the bridge, the outer edge of the conductive pattern being located outside the outer edge of the first wiring pattern and the second wiring pattern in the first wiring layer. The bridge functions as a coplanar line and suppresses generation of electromagnetic field.

Abstract: A semiconductor apparatus comprises a substrate, a semiconductor chip fixedly secured on one side of the substrate, a spirally shaped coil formed on the other side of the substrate and electrically connected to the semiconductor chip, and a conductive pattern formed on a surface of the one side of the substrate facing to the semiconductor chip for stabilizing an inductance characteristic of the coil.

Abstract: A communication apparatus includes, as a plurality of communication functions, an amplifier for amplifying a received signal or a transmitting signal, a balun for converting an unbalanced signal to a balanced signal or converting a balanced signal to an unbalanced signal and a mixer for converting a frequency. A gain reducing unit for reducing a gain of a specific frequency band is installed in at least one of the plurality of communication functions. A band rejection filter, for example, serves as a gain reducing unit and is disposed between a pair of transistors. A plurality of band rejection filters may be so arranged as to be distributed to the plurality of communication functions.

Abstract: A chip capacitor is arranged on a microstrip conductor forming a microstrip line. The chip capacitor has a dielectric material and electrodes provided on both ends thereof. The electrodes of the chip capacitor are connected to the microstrip conductor. A resonance frequency is decided by the length of the microstrip conductor between the electrodes of the chip capacitor, the dielectric constant and the thickness of the dielectric substrate and the capacitance value of the chip capacitor.

Abstract: A chip capacitor is arranged on a microstrip conductor forming a microstrip line. The chip capacitor has a dielectric material and electrodes provided on both ends thereof. The electrodes of the chip capacitor are connected to the microstrip conductor. A resonance frequency is decided by the length of the microstrip conductor between the electrodes of the chip capacitor, the dielectric constant and the thickness of the dielectric substrate and the capacitance value of the chip capacitor.

Abstract: A chip capacitor is arranged on a microstrip conductor forming a microstrip line. The chip capacitor has a dielectric material and electrodes provided on both ends thereof. The electrodes of the chip capacitor are connected to the microstrip conductor. A resonance frequency is decided by the length of the microstrip conductor between the electrodes of the chip capacitor, the dielectric constant and the thickness of the dielectric substrate and the capacitance value of the chip capacitor.

Abstract: A feedback circuit is connected between a drain electrode and a gate electrode of an FET. The feedback circuit is constituted by a series connection of a feedback amount adjusting resistor and an LC series resonance circuit. The LC series resonance circuit is constituted by a series connection of a capacitor and an inductor. The capacitance of the capacitor and the inductance of the inductor are set such that the LC series resonance circuit enters a short-circuited state with respect to an m-th harmonic by resonating at the frequency of the m-th harmonic, and the LC series resonance circuit enters an opened state with respect to a fundamental wave.

Abstract: A feedback circuit is connected between a drain electrode and a gate electrode of an FET. The feedback circuit is constituted by a series connection of a feedback amount adjusting resistor and an LC series resonance circuit. The LC series resonance circuit is constituted by a series connection of a capacitor and an inductor. The capacitance of the capacitor and the inductance of the inductor are set such that the LC series resonance circuit enters a short-circuited state with respect to an m-th harmonic by resonating at the frequency of the m-th harmonic, and the LC series resonance circuit enters an opened state with respect to a fundamental wave.

Abstract: A chip capacitor is arranged on a microstrip conductor forming a microstrip line. The chip capacitor has a dielectric material and electrodes provided on both ends thereof. The electrodes of the chip capacitor are connected to the microstrip conductor. A resonance frequency is decided by the length of the microstrip conductor between the electrodes of the chip capacitor, the dielectric constant and the thickness of the dielectric substrate and the capacitance value of the chip capacitor.

Abstract: A switching circuit device including a multi-gate field effect transistor having a plurality of gate electrodes between a drain electrode and a source electrode, a low resistor having its one end connected between the gate electrodes, and a high resistor connected between the other end of the low resistor and any one of the drain electrode, the source electrode and the end of the other low resistor.

Abstract: A chip capacitor is arranged on a microstrip conductor forming a microstrip line. The chip capacitor has a dielectric material and electrodes provided on both ends thereof. The electrodes of the chip capacitor are connected to the microstrip conductor. A resonance frequency is decided by the length of the microstrip conductor between the electrodes of the chip capacitor, the dielectric constant and the thickness of the dielectric substrate and the capacitance value of the chip capacitor.

Abstract: A communication apparatus for use in a portable telephone is disclosed which has a transmit-receive common amplifier for amplifying a transmitted signal or received signal, and a mixer for frequency-mixing the transmitted signal or the received signal with a local oscillator output, wherein connection between the mixer and an input side of the amplifier and connection between the mixer and an output side of the amplifier are made by means of respective signal-path selector switches. During reception, a deep bias is applied to an FET of the transmit-receive common amplifier to reduce current consumption, and during transmission, a shallow bias is applied to the FET of the transmit-receive common amplifier for increased output.

Abstract: An IC chip characterized in that at least two input pads and at least two output pads are respectively disposed symmetrical to each other about the center of the IC chip, at least two input/output pads are disposed symmetrical to each other about the center, at least one supply voltage pad is disposed in each of four equal sections formed by longitudinally and laterally dividing the IC chip, and at least one control voltage pad is disposed in each of these four sections. The IC chip can be connected by bonding to various types of IC packages having different configurations of the pins only by mounting in a proper direction without causing the bonding wires to bridge over the other constituent elements or to cross each other.

Abstract: A double-balanced mixer circuit which consumes less power, and is capable of operating on a low voltage power source, because an output of a first signal having a phase lag of 90.degree. from a first frequency signal and an output of a second signal having a phase lead of 90.degree. over the first frequency signal are provided by means of a first phase shifter, an output of a third signal having a phase lag of 90.degree. from a second frequency signal and an output of fourth signal having a phase lead of 90.degree. over the second frequency signal are provided by means of a second phase shifter, thereby generating a radio frequency signal by mixing the first signal and the third signal in a first dual gate circuit, and generating a radio frequency signal by mixing the second signal and the fourth signal in a second dual gate circuit.

Abstract: The S-parameters of a transistor are measured at a plurality of bias points, and using a tentatively decided load resistance value, the S-parameters on the load curve are examined, based on which the power gain and input/output power characteristics are obtained to determine the optimum load. Then, by using a linear simulator, input and output circuits are designed so that the optimum load can be realized.

Abstract: An active device such as an HEMT is formed on a GaAs substrate, and characteristics of this active device formed are measured. A circuit pattern of a passive circuit device including a serial microstrip line is simulated on the basis of the results of this measurement, and a circuit pattern obtained by the simulation is directly drawn on a substrate to form the passive circuit device, thereby to fabricate an MMIC. Accordingly, the passive circuit device is formed in conformity with the characteristics of the active device for each chip.As a result, the variation in characteristics of the active device is canceled, to obtain an MMIC superior in matching.