Abstract: A radio interference suppression circuit used in a radio circuit of performing duplex transmission, comprises a first directional coupler of receiving a transmission frequency signal and then bifurcating and outputting the signal; and a second directional coupler which acquires, through one input thereof, a signal outputted from a reception filter of an antenna multiplexer and containing a reception frequency signal and the leakage signal component of a transmission frequency signal, and acquires, through the other input thereof, the transmission frequency signal outputted from one output of the first directional coupler, and which combines and outputs these acquired signals; wherein the leakage signal component of the transmission frequency signal contained in the signal inputted through the one input of the second directional coupler and the transmission frequency signal inputted through the other input of the second directional coupler are adjusted to be substantially of equal amplitude and reversed phase.

Abstract: A high-Q inductor for high frequency, having a plurality of inductor elements formed in a plurality of IC wiring layers with a connection formed therebetween. The directions of the magnetic fields generated by the respective inductor elements are substantially the same. With this construction, the section of the inductor is increased reducing the serial resistance component and an influence of a skin effect in a high-frequency range is eliminated increasing the Q value.

Abstract: To provide a power amplifier circuit with a smaller circuit scale and with good characteristics over a wide range of load impedance. A configuration includes: a DC/DC converter 2108 which delivers a supply voltage from a battery 2111 to a power amplifier 1302 according to control commands from a control circuit 2109; a directional coupler 2101 which outputs a signal from one terminal 2101a according to signal waves received by an antenna 1306 from a second matching circuit 105 and outputs a signal from another terminal 2101b according to reflected waves received from the antenna 1306; and detectors 2102 and 2103 or the like.

Abstract: A voltage controlled oscillator 1, a variable frequency divider 2, a phase comparator 3, and a loop filter 4 form a Phase Locked Loop (PLL). A sigma-delta modulator 5 sigma-delta modulates data obtained by adding a fractional part M2 of the frequency division factor data with modulation data X by using an output signal of the variable frequency divider 2 as a clock. An output signal of the sigma-delta modulator 5 is added to an integral part M1 of the frequency division factor data, and the resultant data becomes effective frequency division factor data 13 of the variable frequency divider 2. An output signal of the sigma-delta modulator 5 also becomes control data 14 after passing through a D/A converter 6, a low-pass filter 7, and an amplitude adjustment circuit 8. The control data 14 is inputted into a frequency modulation terminal of the voltage controlled oscillator 1.

Abstract: An amplitude frequency characteristic adjustment circuit 106 is provided downstream of and connected to a distortion generation circuit 105. An amplitude difference between low-frequency-side and high-frequency-side distortion voltages is adjusted by the amplitude frequency characteristic adjustment circuit 106, and then their amplitudes and phases are adjusted by a vector adjustment circuit 107. This configuration makes it possible to suppress simultaneously both of low-frequency-side and high-frequency-side distortion voltages of a distortion generated by a wide-band class-AB power amplifier even if they are different in amplitude and phase.

Abstract: In a signal generating circuit SG1, a 90-degree divider 3 generates, from a local oscillation signal SLO supplied through an input terminal 1, an intermediate reference phase signal ISREF and an intermediate quadrature signal ISQR orthogonal in phase to the intermediate reference phase signal ISREF for output to mixers 6 and 7, respectively. A shifter 4 shifts the phase of the local oscillation signal supplied through an input terminal 2 by a predetermined amount to generate a shift signal SSFT for output through a divider 5 to the mixers 6 and 7. The mixer 6 mixes the input intermediate reference phase signal ISREF and the input shift signal SSFT to generate a reference phase signal SREF. The mixer 7 mixes intermediate quadrature signal ISQR and the input shift signal SSFT to generate a quadrature signal SQR. With this, it is possible to provide a signal generator capable of generating highly-accurate, high-frequency reference phase signals and quadrature signals.

Abstract: An amplitude frequency characteristic adjustment circuit 106 is provided downstream of and connected to a distortion generation circuit 105. An amplitude difference between low-frequency-side and high-frequency-side distortion voltages is adjusted by the amplitude frequency characteristic adjustment circuit 106, and then their amplitudes and phases are adjusted by a vector adjustment circuit 107. This configuration makes it possible to suppress simultaneously both of low-frequency-side and high-frequency-side distortion voltages of a distortion generated by a wide-band class-AB power amplifier even if they are different in amplitude and phase.

Abstract: A transmitting/receiving switch, in which a transmission terminal connected to a transmission circuit is connected to an antenna terminal through a first switching element, a filter for attenuating harmonic contents in a transmission signal, a phase-shift circuit for significantly increasing an impedance from a node toward said transmission terminal in a reception frequency band by phase-adjusting the amount of phase shift by performing phase adjustment according to the amount of the phase shift generated by said filter. Furthermore, the antenna terminal connected to an antenna ANT is connected to a reception terminal through the node and a second switching element, and the reception terminal is connected to a reception circuit Rx.

Abstract: An antenna duplexer has an antenna terminal;

Abstract: To provide a power amplifier circuit with a smaller circuit scale and with good characteristics over a wide range of load impedance. A configuration includes: a DC/DC converter 2108 which delivers a supply voltage from a battery 2111 to a power amplifier 1302 according to control commands from a control circuit 2109; a directional coupler 2101 which outputs a signal from one terminal 2101a according to signal waves received by an antenna 1306 from a second matching circuit 105 and outputs a signal from another terminal 2101b according to reflected waves received from the antenna 1306; and detectors 2102 and 2103 or the like.

Abstract: A portable celullar phone apparatus includes a portable cellular phone and an external adapter for a portable cellular phone. It is possible to suppress an increase in output power of a portable cellular phone transmit amplifier due to a loss at a transmit switch associated with use of an external transmitting antenna by coupling a first output of the transmit switch to a portable cellular phone transmit amplifier and coupling a second output of the transmit switch to an input of a transmit amplifier part of a portable cellular phone external adapter. Deterioration of a NF of a receiving system due to a loss at a receive switch when using an external receiving antenna may be reduced by coupling a first input of a receive switch to a portable cellular phone receive amplifier and coupling a second input of the receive switch to an output of a receive amplifier part of the portable cellular phone external adapter.

Abstract: A multilayered ceramic RF device having at least one radio frequency filter includes a low temperature-cofired multilayered ceramic body having a plurality of ceramic layers laminated one upon another and fired together. The low temperature-cofired multilayered ceramic body also has a first electrode pattern formed therein and a second electrode pattern formed thereon. The first and second electrode patterns are electrically connected to one another through a via hole. A bare semiconductor chip is mounted on the low temperature-cofired multilayered ceramic body with a face down bonding, and the bare semiconductor chip is coated with a sealing resin. The at least one radio frequency filter is a multilayered filter formed in the low temperature-cofired multilayered ceramic body, and the multilayered filter includes a part of the first and second electrode patterns.

Abstract: A high-Q inductor for high frequency, having a plurality of inductor elements formed in a plurality of IC wiring layers with a connection formed therebetween. The directions of the magnetic fields generated by the respective inductor elements are substantially the same. With this construction, the section of the inductor is increased reducing the serial resistance component and an influence of a skin effect in a high-frequency range is eliminated increasing the Q value.

Abstract: The present invention provides a portable celullar phone and an external adapter for a portable celullar phone, with which it is possible to suppress an increase in an output power of a portable celullar phone transmit amplifier due to a loss at a transmit switch associated with use of an external transmitting antenna, and to reduce a deterioration of an NF of a receiving system due to a loss at a receive switch associated with use of an external receiving antenna. A transmit switch 109, which is disposed before a portable celullar phone transmit amplifier 103 which is disposed in a portable celullar phone 101, is connected to an input of a transmit amplifier part 115 of a portable celullar phone external adapter 112, while a receive switch 110 which is disposed after a portable celullar phone receive amplifier 108 is connected to an output of a receive amplifier part 118 of the portable celullar phone external adapter 112.

Abstract: An amplitude frequency characteristic adjustment circuit 106 is provided downstream of and connected to a distortion generation circuit 105. An amplitude difference between low-frequency-side and high-frequency-side distortion voltages is adjusted by the amplitude frequency characteristic adjustment circuit 106, and then their amplitudes and phases are adjusted by a vector adjustment circuit 107. This configuration makes it possible to suppress simultaneously both of low-frequency-side and high-frequency-side distortion voltages of a distortion generated by a wide-band class-AB power amplifier even if they are different in amplitude and phase.

Abstract: A predistortion circuit has

Abstract: A multi-mode wireless system having a modulator (11) for modulating two system signals (low frequency signals for the GSM system and high frequency signals for the DCS1800 system), a first local oscillator (14) for oscillating a signal of a predetermined frequency, a n-divider (15) for dividing a signal from the first local oscillator by a factor of n, a high frequency mixer (13) for converting a signal to a high frequency side output (17) according to a signal output from the first local oscillator (14) and a signal output from the modulator (11), and a low frequency mixer (12) for outputting a signal to a low frequency mixer (16) according to an n-divided signal and a signal from the modulator (11).

Abstract: A high-frequency oscillating circuit that is not degraded by external electromagnetic interference. The high-frequency oscillating circuit includes first and second oscillating transistors wherein the bases are connected together directly or via a capacitor having a sufficiently low impedance at an oscillating frequency, and wherein a differential signal output is obtained between the emitters of the first and second oscillating transistors. Also provided is a resonating circuit formed in a module and a separate negative-resistance-generating circuit formed on an integrated circuit for achieving an oscillator that has a high Q factor and a high C/N ratio.

Abstract: A voltage-controlled resonator is fabricated by laminating, one on top of the other, a first dielectric which has a resonant circuit and on the upper surface of which a variable-capacitance element is mounted, and a second dielectric which has a through-hole formed in a position thereof corresponding to the position of the variable-capacitance element and which has a dual function of shielding and resonant frequency tuning. With this structure, the height of the resonator can be further reduced compared with the prior art while retaining the shielding effect, and moreover, further precise resonant frequency tuning can be accomplished as compared with the prior art.

Abstract: A filter with a low-noise amplifier includes: two amplification circuits, a first 3-dB hybrid circuit which is connected to an input side of the amplification circuits, a second 3-dB hybrid circuit which is connected to an output side of the amplification circuits, and a filter which is connected to one input terminal of the first 3-dB hybrid circuit. The other input terminal of the first 3-dB hybrid circuit is subjected to matched termination. A signal is inputted to an input terminal of the filter and is outputted from one output terminal of the second 3-dB hybrid circuit and the other output terminal of the second 3-dB hybrid circuit is subjected to matched termination.