Abstract: An amplifier capable of lowering an electrical current flowing in a peak amplifier before a carrier amplifier becomes saturated to thereby improve the efficiency of an entirety of the amplifier is provided. The amplifier includes a carrier amplifier circuit having an amplifying element operable in class-AB or class-B, and a plurality of peak amplifier circuits which have amplifying elements operating in class-B or class-C and which are arranged to start an operation in stages in response to an input level. An output of the carrier amplifier circuit and outputs of the peak amplifier circuits are combined together for signal output. One of the peak amplifier circuits which is rendered operative at the lowest input level is smaller in saturation output than the carrier amplifier circuit.

Abstract: The performance of an amplifying system is improved by achieving adequate matching. The amplifying system for amplifying signals includes distributing means 1 that distribute a signal, a carrier amplifier 2 that amplifies the distributed first signal in Class AB, a peak amplifier 4 that amplifies the distributed second signal in Class B or Class C, a first transmission line having a given electric length and being connected to an output of the carrier amplifier, a second transmission line having a given electric length and being connected to an output of the peak amplifier, and a combining end 18 for combining an output of the first transmission line and an output of the second transmission line.

Abstract: A distortion compensation apparatus includes distortion generating means for generating distortions to compensate for a distortion generated in an amplifier 2. The distortion generating means includes a nonlinear circuit 13 having an input/output expansion characteristic as a circuit which generates a distortion of the lowest odd order as a compensation target and also includes a nonlinear circuit 18 having an input/output saturation characteristic as a circuit which generates a distortion of another odd order as a compensation target.

Abstract: An amplifying apparatus includes a splitting unit for splitting an input signal into a first split signal and a second split signal; phase-shifting unit for phase-shifting the first split signal and the second split signal, respectively; a first amplifying unit for amplifying a first phase-shifted signal and outputting the signal as a first output signal; a second amplifying unit for amplifying, in a substantially identical manner to the first amplifying unit, a second phase-shifted signal and outputting the signal as a second output signal; and a matching unit for matching the first output signal and the second output signal to a first transmission unit and a second transmission unit, respectively. The first transmission unit is for transmitting the first output signal from the matching unit to a load resistor, and the second transmission unit is for transmitting the second output signal from the matching unit to the load resistor.

Abstract: A wireless system for use in a low power data communications in a sub-millimeter wave zone includes at least one wireless communications device including a directional antenna whose cross-polarization discrimination is not less than 24 dB, wherein the wireless system uses a plurality of planes of polarization selectively. The planes of polarization to be used are selected such that the number of non-occupied channels is largest by detecting the number of non-occupied channels depending on planes of polarization. The directional antenna, having a box shape whose front view is a right square, is formed as a single body with the wireless communications device, and the wireless communications device is fixed to a pole in a way that each side of the right square is slanted at 45° with respect to the pole.

Abstract: There is provided an amplifier for combining outputs of a plurality of amplifying circuits to generate an amplifier output. The amplifier includes a first amplifying circuit for operating a first amplifying device in class-AB, wherein the first amplifying circuit is one among the plurality of the amplifying circuits; a second amplifying circuit for operating a second amplifying device in class-B or class-C, wherein the second amplifying circuit is one among the plurality of the amplifying circuits; and a summing node at which an output of the first amplifying circuit is combined with an output of the second amplifying circuit via a first impedance transformer containing a transmission line of an electrical length other than ?/4. The second amplifying device is connected to the summing node via an output matching circuit and a second impedance transformer containing a transmission line.

Abstract: A high frequency power amplifier includes an amplifying device for amplifying an input high frequency signal, a harmonic reflection circuit for reflecting a harmonic outputted from the amplifying device, and a harmonic generating circuit provided at an input terminal of the amplifying device, the harmonic generating circuit including a divider for dividing an input signal of a fundamental wave into two parts, a harmonic generator for generating a second harmonic from one part of the fundamental wave signal, and a combiner for combining the second harmonic generated from the harmonic generator with the other part of the fundamental wave signal to offer a combined signal to the amplifying device, wherein the harmonic reflection circuit reflects the second harmonic.

Abstract: The performance of an amplifying system is improved by achieving adequate matching. The amplifying system for amplifying signals includes distributing means 1 that distribute a signal, a carrier amplifier 2 that amplifies the distributed first signal in Class AB, a peak amplifier 4 that amplifies the distributed second signal in Class B or Class C, a first transmission line having a given electric length and being connected to an output of the carrier amplifier, a second transmission line having a given electric length and being connected to an output of the peak amplifier, and a combining end 18 for combining an output of the first transmission line and an output of the second transmission line.

Abstract: A distortion compensation apparatus includes distortion generating means for generating distortions to compensate for a distortion generated in an amplifier 2. The distortion generating means includes a nonlinear circuit 13 having an input/output expansion characteristic as a circuit which generates a distortion of the lowest odd order as a compensation target and also includes a nonlinear circuit 18 having an input/output saturation characteristic as a circuit which generates a distortion of another odd order as a compensation target.

Abstract: A first control unit controls a bias applied to the peak amplifier to (a) make a peak amplifier operate as class C when the level of the input signal is lower than a first threshold value, to (b) make the peak amplifier operate as class AB with a second conduction angle substantially equal to a first conduction angle, when the level of the input signal is higher than a second threshold value higher than the first threshold value, and to (c) make the peak amplifier operate as class AB with a third conduction angle smaller than the first conduction angle, when the level of the input signal is not less than the first threshold value and not more than the second threshold value.

Abstract: A conventional power amplifying device has a problem that when a signal band is widened, sampling frequency for distortion detection is increased and an FFT calculation amount of a distortion compensation unit is increased, which increase a circuit size and power consumption. The present invention provides a non-linear distortion detection method and a distortion compensation amplifying device capable of suppressing increase of the circuit size and the power consumption even if the signal band is widened. A signal obtained by feeding back an output of a power amplifier is sampled by an A/D converter. An equalizer of a distortion detection unit uses an input signal d(n) of a predistorter as a reference symbol to detect an equalization error e(n) of the orthogonal demodulation signal u(n). An absolute value averaging unit outputs an absolute value of the equalization error e(n) which has been temporally averaged to E(n) as a distortion value to a control unit.

Abstract: Silicon carbide-based fine particles containing an electrically conducting inorganic substance and a electromagnetic wave absorbing material, which are fine particles comprising a particle inner portion of a silicon carbide-based material and a surface layer formed of an electrically conducting inorganic substance mainly comprising carbon, wherein a gradient layer with the compositional ratio of the electrically conducting inorganic substance gradiently increasing toward the particle surface is present and the thickness of the electrically conducting inorganic substance gradient layer is from 1 to 500 nm. The electromagnetic wave absorbing material of the present invention can selectively absorb a electromagnetic wave of 1 to 300 GHz in a wide band.

Abstract: The radio signal receiving device that has an input terminal for inputting an input signal and an output terminal for amplifying the signal inputted to the input terminal and then outputting the signal, comprises an insulating container comprising the input terminal and the output terminal, and an amplifier that is contained in the insulating container and amplifies the signal and then outputs the signal as the output signal. Bias voltage from one of the amplifier input terminal of the amplifier and the amplifier output terminal of the amplifier is applied to the output signal outputted to the amplifier output terminal of the amplifier.

Abstract: A distortion compensator for compensating for distortion produced in an amplifier that amplifies a signal includes a signal level detector for detecting a level of a signal to be amplified and a distortion compensator for conducting distortion compensation based on the detection result separately for each frequency band signal of multiple frequency band signals contained in the signal to be amplified. The distortion compensator improves distortion compensation performance by reducing the effect of frequency characteristics that restrict the distortion compensation performance limit.

Abstract: A wireless system for use in a low power data communications in a sub-millimeter wave zone includes at least one wireless communications device including a directional antenna whose cross-polarization discrimination is not less than 24 dB, wherein the wireless system uses a plurality of planes of polarization selectively. The planes of polarization to be used are selected such that the number of non-occupied channels is largest by detecting the number of non-occupied channels depending on planes of polarization. The directional antenna, having a box shape whose front view is a right square, is formed as a single body with the wireless communications device, and the wireless communications device is fixed to a pole in a way that each side of the right square is slanted at 45° with respect to the pole.

Abstract: A crystalline polymer exhibiting crystal transition in the solid phase state, which satisfies the relationship defined by the formula 150>?Htr>1.6Ttr?3.5 (1) (wherein ?Htr represents the endotherm (J/g) accompanying crystal transition and Ttr represents the crystal transition temperature (° C.)). This crystalline polymer has a weight average molecular weight of 600 thousand or less and a crystal transition temperature (Ttr) of 67° C. or below. Since this crystalline polymer has a low phase transition temperature, a high heat of a crystal transition, and a high melting point, the potential utility thereof as a switching element or a thermal storage material used at around normal environment temperatures (20 to 50° C.) is high.

Abstract: There is provided an amplifier for combining outputs of a plurality of amplifying circuits to generate an amplifier output. The amplifier includes a first amplifying circuit for operating a first amplifying device in class-AB, wherein the first amplifying circuit is one among the plurality of the amplifying circuits; a second amplifying circuit for operating a second amplifying device in class-B or class-C, wherein the second amplifying circuit is one among the plurality of the amplifying circuits; and a summing node at which an output of the first amplifying circuit is combined with an output of the second amplifying circuit via a first impedance transformer containing a transmission line of an electrical length other than ?/4. The second amplifying device is connected to the summing node via an output matching circuit and a second impedance transformer containing a transmission line.

Abstract: The present invention relates to an economical and highly reliable receiving apparatus for receiving radio signals transmitted from a mobile communication terminal within radio zone. The receiving apparatus has antenna sections that receive radio signals transmitted from the mobile communication terminal and are provided in each of a plurality of sectors divided from the radio zone, and receiving units that are provided in each of the antenna sections and that perform a predetermined process to the radio signals received by the antenna section.

Abstract: To provide an amplifying device which is reduced in size, weight and cost and which can improve the distortion compensation performance. In the amplifying device, input signals are each subjected to digital orthogonal modulation using an IF and further to offset rotation processing in digital orthogonal modulators, then bifurcated into a main signal system and a control system, and detection of a power value is performed at an IF band in a power detecting section of the control system. Therefore, offset rotation processing of the input signals in the power detection is not required, so that a structure for matching phases of a multi-carrier signal and a power value signal is not required, resulting in improving the distortion compensation performance without using an analog delay line.

Abstract: A peak limiter for use in a system for amplifying a multi-carrier signal receives a baseband signal of each carrier of the multi-carrier signal. The multi-carrier signal is computationally estimated to have carriers combined in an RF band, and obtains power information of the multi-carrier signal to limit an amplitude of the baseband signal based on the power information of the estimated multi-carrier signal to thereby provide peak-limited baseband signals. Thus, the distortion generated by performing the unnecessary peak limitation can be effectively prevented to thereby improve the reliability of the entire system.