Abstract: A variable gain amplifying apparatus has an amplifier, one or more first switching elements connected in parallel to the amplifier, and a phase shifter connected in series to the first switching element. The first switching element is enabled if the level of an input signal or an output signal is higher than a predetermined level, and the first switching element is disabled if the level of the input signal or the output signal is equal to or lower than the predetermined level. The amplifier does not operate when the first switching element is enabled, and the amplifier operates when the first switching element is disabled, and the amount of phase shift when the input signal is passed through the amplifier and phase shifter is substantially equal to the amount of phase shift when the input signal is passed through the first switching element.

Abstract: A frequency conversion circuit is provided capable of suppressing noise converted from about a frequency twice as large as a local signal to a reception band frequency, which performs modulation by mixing an input signal with a local signal. The frequency conversion circuit includes a first transistor whose base is electrically connected with one of a first input terminal pair inputted with the input signal; a second transistor whose base is electrically connected with the other of the first input terminal pair; third and fourth transistors whose emitters are electrically connected respectively with a collector of the first transistor; fifth and sixth transistors whose emitters are electrically connected respectively with a collector of the second transistor; and a differential noise suppression circuit provided between the collector of the first transistor and the collector of the second transistor.

Abstract: Provided is a capacitor integrated in a semiconductor device which allows a large capacitance per unit area; small production variations in a capacitance; a high Q-value; and a high self-resonant frequency. To attain this, each of a first wiring layer and a second wiring layer includes a wire group on an input side and a wire group on an output side. A lead-out wire included in the wire group on the input side in the first wiring layer and a lead-out wire included in the wire group on the input side in the second wiring layer are disposed so as to overlap with each other when viewed from a direction of lamination of the wiring layers. A lead-out wire included in the wire group on the output side in the first wiring layer and a lead-out wire included in the wire group on the output side in the second wiring layer are disposed so as to overlap with each other when viewed from the direction of lamination of the wiring layers.

Abstract: A variable gain amplifying apparatus has an amplifier, one or more first switching elements connected in parallel to the amplifier, and a phase shifter connected in series to the first switching element. The first switching element is enabled if the level of an input signal or an output signal is higher than a predetermined level, and the first switching element is disabled if the level of the input signal or the output signal is equal to or lower than the predetermined level. The amplifier does not operate when the first switching element is enabled, and the amplifier operates when the first switching element is disabled, and the amount of phase shift when the input signal is passed through the amplifier and phase shifter is substantially equal to the amount of phase shift when the input signal is passed through the first switching element.

Abstract: A low-noise differential bias circuit is provided which obtains excellent noise characteristics while ensuring excellent distortion characteristics. A collector of a transistor Q11 is connected to a voltage supply point (Vcc) via a resistor R15. A base of the transistor Q11 is connected to a base of a transistor Q1 via resistors R13, R11 connected in series. A connection point between the resistors R11, R13 is connected to the collector of the transistor Q11. A collector of a transistor Q12 is connected to the voltage supply point at connection point A via a resistor R16. A base of the transistor Q12 is connected to a base of a transistor Q2 via resistors R14, R12 connected in series. A connection point between the resistors R12, R14 is connected to the collector of the transistor Q12. By this configuration, a high frequency ground is performed at the connection point A.

Abstract: A switch circuit device with improved insertion loss characteristics and isolation characteristics is provided. The switch circuit of the present invention includes a plurality of n-ch MOSFETs whose gates are connected together and whose drains and sources are connected in series, a p-ch MOSFET whose gate is connected to the gates of the plurality of n-ch MOSFETs and whose drain is connected to the source and drain of at least one pair of adjacent n-ch MOSFETs, and a voltage changing circuit for applying a low voltage to the source of the p-ch MOSFET while a high-level control voltage is applied to the gate of the p-ch MOSFET, and a high voltage to the source of the p-ch MOSFET while a low-level control voltage is applied to the gate of the p-ch MOSFET.

Abstract: Reception signals received by first to fourth antennas 11 to 14 are sequentially selected one by one repeatedly in accordance with first to fourth switches 31 to 34 being controlled by first to fourth switch control circuits 41 to 44, respectively, so as to be inputted to a signal shaping section 60. The reception signals having been shaped by the signal shaping section 60 are sampled by a sample-and-hold section 71 and AD-converted by an AD converter 72 in accordance with a time at which the reception signals are sequentially selected. The resultant signals are converted into parallel signals by a serial-parallel conversion section 73. Thus, the parallel signals are obtained as the reception signals of the first to the fourth antennas 11 to 14.

Abstract: An amplifier circuit amplifies a signal inputted from an input terminal. A first feedback circuit is placed across an emitter of a bipolar transistor and an input of the amplifier circuit. A second feedback circuit is placed across the input and an output of the amplifier circuit for feeding the output of the amplifier circuit back to the input of the amplifier circuit. A phase change amount in the feedback circuit is determined by the values of an inductor and a capacitor. The values of these elements are selected so that a phase of a signal in which fundamental waves included in two feedback signals are combined and a phase of a signal in which second harmonics included in the two feedback signals are combined are shifted by approximately 180 degrees from a phase of a fundamental wave of an input signal.

Abstract: Radio communication apparatus comprising an antenna, a transmitting circuit of outputting a transmitting signal in a first frequency band. A duplexer connected to the antenna and having a single-phase input terminal and a balanced output terminal, conveying the transmitting signal inputted to the single-phase input terminal to the antenna. The duplexer outputs a receiving signal in a second frequency band different from the first frequency band received from the antenna substantially as a differential signal from the balanced output terminal. A receiving circuit connected to the balanced output terminal and having a circuit in which a gain of a signal of a differential component is higher than that of a signal of an in-phase component, or a loss of the signal of the differential component is lower than that of the signal of the in-phase component.

Abstract: A high frequency variable gain amplification device 100 includes: a feedback circuit 103 capable of changing a feedback impedance to adjust the gain of an amplifier 101 in accordance with a control signal from a control device 200; and a current consumption adjustment circuit 102 capable of adjusting current consumption of the amplifier 101. The control device 200 controls the feedback impedance and the current consumption based on a desired signal power level and an undesired signal power level. If the desired signal power level exceeds a predetermined value, the control device 200 reduces the feedback impedance to increase the amount of a feedback signal, thereby allowing the amplifier 101 to operate with low gain so as to prevent the distortion characteristic from being reduced and to reduce the current consumption.

Abstract: Radio communication apparatus comprising an antenna, a transmitting circuit outputting a transmitting signal in a first frequency band. A duplexer connected to the antenna and having a single-phase input terminal and a balanced output terminal, conveying the transmitting signal inputted to the single-phase input terminal to the antenna. The duplexer outputs a receiving signal in a second frequency band different from the first frequency band received from the antenna substantially as a differential signal from the balanced output terminal. A receiving circuit connected to the balanced output terminal and having a circuit in which a gain of a signal of a differential component is higher than that of a signal of an in-phase component, or a loss of the signal of the differential component is lower than that of the signal of the in-phase component.

Abstract: With an antenna duplexer having balanced terminals, there has been a problem that the amount of leakage of common-mode signal components in the balanced terminals is large. A balanced high-frequency filter designed to solve this problem comprises a balanced high-frequency element and a phase-shifting circuit which includes a transmission line and placed between output terminals, and which is series resonance circuit having a length set to ?T/2 (?T: the wavelength at a frequency in a transmission frequency band) and capable of resonating with common-mode signal components at a predetermined frequency.

Abstract: A multistage amplifying device for amplifying a desired signal comprise first to N-th amplifiers connected in cascade,wherein the k-th (k is 1 to N) amplifier includes a k-th amplification section; and a k-th feedback section which has a reactance component, changes a phase of a signal output from the k-th amplification section. When a phase difference between the desired signal output from the N-th amplifier and a third-order inter-modulation distortion(IM3) output from the (N?1)-th amplifier is referred to as a first phase, and a phase difference between the desired signal output from the N-th amplifier, and a combined IM3 obtained by combining a IM3 occurring in the N-th amplification section and a IM3 fed back from the N-th feedback section is referred to as a second phase, a difference between the first phase and the second phase is 120° or more and 180° or less.

Abstract: A balanced high-frequency device includes a balanced element; at least one balanced terminal connected to the balanced element; a phase circuit having at least first, second, and third impedance elements, and electrically connected between the balanced element and the balanced terminal. The first impedance element and the second impedance element are connected between the balanced terminals in series, the connection point between the first impedance element and the second impedance element is grounded through the third impedance element, a series resonant circuit is formed by the first impedance element and the third impedance element. A series resonant circuit is formed by the second impedance element and the third impedance element, and an impedance to a differential signal component in the passing band of the balanced elements of the first and second impedance elements is set so as to increase to the ground plane.

Abstract: In a thermal head provided with a resistance layer having a plurality of heating element portions which generate heat by energization, an insulating barrier layer which determines the two-dimensional size of each heating element portion by covering each heating element portion, and electrode layers electrically connected to two end portions of each of the plural heating element portions, in the length direction of the resistance, a heat transfer layer is disposed on at least the insulating barrier layer to determine the two-dimensional surface exposure area of the insulating barrier layer by covering part of the insulating barrier layer and to dissipate the heat generated from the plural heating element portions, and surface exposure regions of the insulating barrier layer are specified as effective heating regions of the plural heating element portions by adjusting the two-dimensional size of the heat transfer layer.

Abstract: A cathode ray tube includes an electron gun for emitting at least one electron beam; a mask frame include a mask having a plurality of holes or slits for allowing the electron beam to be transmitted therethrough and a frame to which the mask is attached; and a panel including a phosphor layer to be scanned by the at least one electron beam transmitted through the plurality of holes or slits of the mask. The panel includes a plurality of stud pins for supporting the frame. The frame includes a plurality of elastic supports engaged with the plurality of stud pins. At least one of the plurality of elastic supports includes an engagement portion having an engaging hole which is engaged with one of the plurality of the stud pins and an elastic portion in contact with the one stud pin. Mask frame vibration causes the elastic portion to rub against a respective stud pin so as to generate a frictional force for attenuating the vibration of the mask frame.

Abstract: A cathode ray tube includes an electron gun for emitting at least one electron beam; a mask frame include a mask having a plurality of holes or slits for allowing the electron beam to be transmitted therethrough and a frame to which the mask is attached; and a panel including a phosphor layer to be scanned by the at least one electron beam transmitted through the plurality of holes or slits of the mask. The panel includes a plurality of stud pins for supporting the frame. The frame includes a plurality of elastic supports engaged with the plurality of stud pins. At least one of the plurality of elastic supports includes an engagement portion having an engaging hole which is engaged with one of the plurality of the stud pins and an elastic portion in contact with the one stud pin. Mask frame vibration causes the elastic portion to rub against a respective stud pin so as to generate a frictional force for attenuating the vibration of the mask frame.

Abstract: An amplifier circuit amplifies a differential signal supplied by a pair of input terminals. A phase controller circuit is placed between the emitters of two bipolar transistors and the ground. A feedback circuit is placed across the input and the output of the amplifier circuit for feeding the output of the amplifier circuit back to the input thereof. A phase change amount in the amplifier circuit is determined by the values of two inductors, whereas a phase change amount in the feedback circuit is determined by the values of two resistances and capacitors. The values of these devices are selected so that a phase difference between an input signal and a feedback signal is approximately 180 degrees in a range from the frequency of a fundamental wave of the input signal to the frequency of a second harmonic thereof.

Abstract: A fraction part control circuit of a frequency synthesizer apparatus including a PLL circuit is of a plural-n-th-order delta-sigma modulator circuit for controlling a fraction part of a number of frequency division to a variable frequency divider of the PLL circuit. An adder adds data of the fraction part to an output data from a multiplier and outputs the resultant data to a quantizer through a second-order integrator. The quantizer quantizes input data with a quantization step and outputs the quantized data to the multiplier through a feedback circuit. The quantized data is used as data of the controlled fraction part. The multiplier multiplies data from the feedback circuit by the quantization step and outputs the resultant data to the adder. The fraction part control circuit periodically changes the data of the fraction part, thereby setting a frequency of an output signal from a VCO according to an average value of the period.

Abstract: In order to enhance a reverse isolation characteristic of a differential amplifier, which is used as, for example, an RE amplifier or a local amplifier of a mobile telephone, differential amplifier is provided which includes a differential amplification circuit for amplifying a difference in potential between two input signals in reverse phase with each other, which are inputted into Port1 and Port2, and for outputting two output signals in reverse phase with each other from Port3 and Port4; a feedback capacitor connected between Port and Port4; and a feedback capacitor connected between Port2 and Port3. Signals for canceling feedback signals are inputted into input terminals via the feedback capacitors, whereby it is possible to the reverse isolation characteristic of the differential amplifier.

Abstract: In a well treatment method, a fluid is positioned in a wellbore have formation perforations in alignment with the portion thereof to be treated. A gas generator is positioned in proximity with the fluid and is actuated to disperse the fluid within the wellbore in accordance with a pressure/time relationship. In the preferred embodiment of the invention, the fluid is a fluid resin material which is polymerized following operation of the gas generator to form a consolidated, porous, permeable matrix which retains sand and other fine materials while permitting the flow of production fluid into the well.