Abstract: The disclosure includes a case of a portable electronic device such as a cell phone, the case including a first well for receiving the portable electronic device and a secondary well. The case may include a thin layer of material on the exterior surface of the back wall of the case. The back wall of the case may include an aperture for receiving a portion of a silicone strip or finger loop, the aperture registering with an aperture in the thin layer of material. The aperture in the back wall of the case may include a flange or annular ridge on the exterior surface of the back wall, the flange or annular ridge preferably being level with the exterior surface of the thin layer of material.

Abstract: An unbalanced terahertz frequency doubler circuit with power handling capacity is provided, and the circuit includes a RF input waveguide, a quartz substrate and a RF output waveguide, where one end of the quartz substrate is disposed in a waveguide groove of the RF input waveguide and the other end of the quartz substrate is disposed in a waveguide groove of the RF output waveguide, where an input transition microstrip is disposed on the quartz substrate, and one end of the transition microstrip is connected to an output transition microstrip sequentially through a first transmission microstrip, a low pass filter, a RF matching microstrip and a second transmission microstrip, where anodes of four GaAs-based terahertz frequency multiplier diode groups are connected to the RF matching microstrip, and a cathode at the outermost position of each of the GaAs-based terahertz frequency multiplier diode groups is connected to a grounding quartz strip.

Abstract: A communication circuit may include mixers configured to generate voltage mode outputs. The communication circuit may further include voltage nodes configured to sum the voltage mode outputs produced by the mixers to generate intermediate voltage mode signals. The communication circuit may further include transconductors configured to convert the intermediate voltage mode signals to intermediate current mode signals. The communication circuit may further include at least one current node configured to sum the intermediate current mode signals to generate at least one mixer output signal.

Abstract: Input image information is received. A processor device is used for determining enhancement information based on frequency characteristics and edge information of the input image information. The enhancement information is mixed with the input image information to generate an enhanced image.

Abstract: Provided is an image sensing device that includes a detector configured to detect a terahertz wave signal received by a receiving antenna, a voltage-controlled oscillator configured to output an oscillation frequency according to an output voltage of the detector, and a frequency digital converter configured to convert the oscillation frequency output from the voltage-controlled oscillator to a digital signal.

Abstract: Input image information is received. Enhancement information is determined based on frequency characteristics of the input image information. The enhancement information is mixed with the input image information to generate an enhanced image.

Abstract: A system is provided for transmitting signals. The system includes a ground-referenced single-ended signaling (GRS) driver circuit that is configured to pre-charge a first capacitor to store a first charge between a first output node and a first reference node based on a first input data signal during a first pre-charge phase and drive an output signal relative to a ground network based on the first charge during a first drive phase. A control circuit is configured to generate a first set of control signals based on the first input data signal and a first clock signal, where the first set of control signals causes the first GRS driver circuit to operate in either the first pre-charge phase or in the first drive phase.

Abstract: A mixer including a field effect transistor having a source, a drain and a gate, an input port coupled to the source or to the drain of the field effect transistor, an output port coupled to the drain of the field effect transistor if the input port is coupled to the source, or coupled to the source of the field effect transistor if the input port is coupled to the drain, a local oscillator for mixing a first frequency on the input port to a second frequency on the output port, a first micro-strip line coupling the local oscillator to the gate, and a shunt resistor capacitor termination coupled to the gate. The shunt resistor capacitor termination includes a resistor in series with a capacitor.

Abstract: A compact high frequency switch needing no external control signal is obtained. The high frequency switch includes an anti-parallel diode (first anti-parallel diode) having one end and another end coupled with an antenna terminal (first high-frequency-signal input/output terminal) and a transmitting terminal (second high-frequency-signal input/output terminal), respectively, and becoming a conduction state in the input power not less than predetermined high frequency power. When the high frequency switch is an SPDT type, such a switch may include a ¼-wavelength line in the use frequency of the high frequency switch having one end and another end coupled with the antenna terminal and a receiving terminal (third high-frequency-signal input/output terminal), respectively, and an anti-parallel diode (second anti-parallel diode) coupled between the receiving terminal and a ground and becoming a conduction state in the input power not less than predetermined high frequency power.

Abstract: A frequency converter includes: a plurality of mixers each including a magnetoresistance effect device including a fixed magnetic layer, a free magnetic layer, and a nonmagnetic spacer layer sandwiched between the fixed magnetic layer and the free magnetic layer, when receiving a first high-frequency signal and a local second high-frequency signal, the magnetoresistance effect device multiplying the first high-frequency signal and the local second high-frequency signal by a magnetoresistance effect to generate a multiplication signal, and a magnetic field applying unit that applies a magnetic field to the free magnetic layer. A plurality of multiplication signals generated when the first high-frequency signal and the local second high-frequency signals that differ from one mixer to another are input to the mixers, are added together and are output.

Abstract: Embodiments of a synchronous data system and method for generating phase-aligned output data are generally described herein. In some embodiments, the synchronous data system includes a plurality of transmitter-receiver (TX-RX) pairs, each associated with a delay-locked loop (DLL) and arranged to generate corresponding output data stream based on a high-speed clock of the associated TX-RX pair. The DLL associated with each TX-RX pair is a phase-shifter DLL that includes an adjustable phase shifter arranged to minimize the phase error between the system clock and the module clock to edge-align the high-speed clocks of each TX-RX pair.

Abstract: A filtering system includes a first filtering module, which includes a first frequency translating device and a first filter. The first frequency translating device includes a center frequency control end that receives a first control signal and an input end that receives an input signal, and performs a first frequency translation on the input signal by utilizing a first control frequency of the first control signal as a center frequency. The first filter performs a first filter on the input signal according to equivalent impedance of a circuit coupled to the input end, and generates in collaboration with the first frequency translating device a first filtered input signal at an output end of the filtering system. The equivalent impedance determines a bandwidth of the first filtered input signal.

Abstract: A time domain switching analog-to-digital converter apparatus and methods of utilizing the same. In one implementation, the converter apparatus comprises a carrier signal source, and at least one reference source. The carrier signal is summed with the input signal and the summed modulated signal is fed to a comparator circuit. The comparator is configured detects crossings of the reference level by the modulated waveform thereby generating trigger events. The time period between consecutive trigger events is used to obtain modulated signal deviation due to the input signal thus enabling input signal measurement. Control of the carrier oscillation amplitude and frequency enables real time adjustment of the converter dynamic range and resolution. The use of additional reference signal levels increases sensor frequency response and accuracy. A dual channel converter apparatus enables estimation and removal of common mode noise, thereby improving signal conversion accuracy.

Abstract: A frequency shifter configured to shift the frequency of a signal, the frequency shifter comprising: a resonant structure configured to mechanically resonate at a first frequency; and a plurality of capacitors, each capacitor having a variable plate separation distance, wherein the resonant structure is configured to cause the plate separation distance of each capacitor to oscillate so as to cause the frequency of the signal to shift by the first frequency.

Abstract: A sensor circuit for obtaining physical quantities with a small margin of error even when the temperature varies is provided. The sensor circuit includes a sensor, a sampling circuit for obtaining a voltage value or a current value of a signal output from the sensor during a predetermined period and holding the value, and an analog-to-digital converter circuit for converting the held analog voltage value or current value into a digital value. The sampling circuit includes a switch for obtaining the voltage value or the current value and holding the value. The switch includes a transistor including an oxide semiconductor in a channel formation region.

Abstract: To provide a frequency conversion device which uses a magneto-resistive device and thereby can correspond to a Si-based MMIC and a GaAs-based MMIC. A frequency conversion apparatus according to the present invention includes: a frequency conversion device made of a magneto-resistive device including a magnetic free layer, an intermediate layer, and a magnetic pinned layer; a magnetic field applying mechanism for applying a magnetic field to the frequency conversion device; a local oscillator for applying a local oscillation signal to the frequency conversion device; and an input terminal electrically connected to the frequency conversion device, and used to input an external input signal.

Abstract: The disclosed invention relates to a transceiver system configured to cancel RF second-order intermodulation distortion (IMD2) within a differential reception path. In some embodiments, the transceiver system has one or more common-mode attenuation elements that attenuate common-mode interferer signals within the differential reception path. The common-mode attenuation elements detect a common-mode interferer from one or more nodes within a transceiver system front-end. One or more properties of the detected common-mode interferer are adjusted and then fed into the differential reception path, where the adjusted common-mode signal attenuates the common-mode interferers. In other embodiments, the differential reception path has a tunable amplifying stage. The tunable amplifying stage has first and second amplifier elements that are independently operated to intentionally introduce an operating parameter mismatch between the elements.

Abstract: A coplanar waveguide (CPW) based subharmonic mixer working at 670 GHz using GaAs Schottky diodes. One example of the mixer has a LO input, an RF input and an IF output. Another possible mixer has a LO input, and IF input and an RF output. Each input or output is connected to a coplanar waveguide with a matching network. A pair of antiparallel diodes provides a signal at twice the LO frequency, which is then mixed with a second signal to provide signals having sum and difference frequencies. The output signal of interest is received after passing through a bandpass filter tuned to the frequency range of interest.

Abstract: A transistor-based switch is coupled to a replica circuit that includes transistor circuitry similar to that of the switch. The replica circuit biases a switched transistor to promote linear operation of the switch.

Abstract: A passive frequency translator with positive conversion voltage gain including at least one input node for receiving an input signal, at least one output node for providing an output signal, and a network coupled to the at least one input node and to the at least one output node, in which the network includes multiple capacitors and switches operatively coupled thereto. The switches are controlled by corresponding clock signals to capture charge of the input signal onto the capacitors and to develop the output signal by performing frequency translation of the input signal by a mixing frequency in such a manner that DC energy of the input signal is substantially blocked from the output signal. The output signal has a net voltage gain relative to the input signal in which energy of the output signal is predominantly derived from energy of the input signal.

Abstract: A sampling circuit and a receiver with which filter characteristics compatible with the reception of wideband signals can be realized with a high degree of freedom in the setting of the filter characteristics. More specifically, the sampling circuit is capable of removing adjacent interfering wave signals while keeping in-band deviation small. The sampling circuit is equipped with a discrete-time analog processing circuit group, wherein multiple discrete-time analog processing circuits are connected in parallel, a synthesizer that synthesizes the output signals from each of the circuit systems and outputs same, and a digital control unit that outputs control signals. Each of the discrete-time analog processing circuits is configured to include multiple rotate capacitor units, which each includes a main rotate capacitor and a sub-rotate capacitor, and only the main rotate capacitors share electric charge with a buffer capacitor included in the synthesizer.

Abstract: A MMIC (microwave monolithic integrated circuit) based FET mixer and method for the same is provided. In particular, adjacent transistors, such as FETs (field effect transistors) share terminals reducing physical layout separation and interconnections. A smaller die size is realized with the improved system geometry herein provided.

Abstract: A cascaded directional couplers circuit having capacitive compensation such that the directivity of a resistively terminated one of the cascaded couplers is not degraded by an inductance of the other one of the cascaded directional couplers.

Abstract: A voltage control oscillator includes: first and second field effect transistors, a drain of one of which is connected to a gate of the other and a drain of the other of which is connected to a gate of the one; third and fourth field effect transistors, a drain of one of which is connected to a gate of the other and a drain of the other of which is connected to a gate of the one; a first inductor connected between the drain of the first field effect transistor and the drain of the second field effect transistor; a second inductor connected between the drain of the third field effect transistor and the drain of the fourth field effect transistor; a third inductor magnetically coupled to the first inductor; a fourth inductor magnetically coupled to the second inductor; a first capacitor that capacitively couples one end of the third inductor and one end of the fourth inductor; and a second capacitor that capacitively couples the other end of the third inductor and the other end of the fourth inductor.

Abstract: The present invention provides a frequency converter including a frequency conversion device capable of accommodating a Si-series MMIC and also a GaAs-series MMIC by using a magneto-resistance element. A frequency converter according to an embodiment of the present invention includes: a frequency conversion device having a magneto-resistance element with a magnetization free layer, an intermediate layer, and a magnetization pinned layer; a magnetic field application mechanism for applying a magnetic field to the frequency conversion device; a local oscillator for applying a local oscillation signal to the frequency conversion device; and an input terminal electrically connected to the above frequency conversion device for receiving an external input signal. Further, the local oscillator includes a magneto-resistance element capable of generating the local oscillation signal by outputting an AC voltage according to a resistance change thereof.

Abstract: A novel DDCR RF front-end for use in UWB applications combining a distributed approach which provides wideband functionality of the RF front-end with I-Q requirement of DCRs. The distributed architecture uses composite cells of a merged LNA and mixer along the input RF T-line.

Abstract: Aspects of a method and system for configurable Active/Passive Mixer and Shared GM Stage may include configuring an RF mixer in frequency demodulator to operate in an active mode or a passive mode. An in-phase (I) processing path and a quadrature (Q) processing path of the RF mixer may utilize a single shared GM stage. One or more switches may be activated to enable the active mode or the passive mode of operation for the RF mixer.

Abstract: A transceiver for radio-frequency communication comprises a waveguide, a transmitting port, a receiving port and a receiver load termination. The waveguide receives and transmits radio-frequency signals. The transmitting port is connected to the waveguide and transmits the radio-frequency signals to the waveguide. The receiving port is connected to the waveguide and receives the radio-frequency signals from the waveguide. The receiver load termination is connected to the waveguide and removes the vertical polarization components of the receiving radio-frequency signals. The receiver load termination includes a filtering unit to reduce the energy of the transmitting radio-frequency signals entering the receiver load termination.

Abstract: Techniques for providing voltage-controlled oscillator circuits having improved phase noise performance and lower power consumption. In an exemplary embodiment, a voltage controlled oscillator (VCO) is coupled to a mixer or a frequency divider such as a divide-by-two circuit. The VCO includes a transistor pair with magnetically cross-coupled inductors, and variable capacitance coupled to the gates of the transistor pair. In an exemplary embodiment, a frequency divider is configured to divide the frequency of the differential current flowing through the transistor pair to generate the LO output. In an alternative exemplary embodiment, a mixer is configured to mix the differential current flowing through the transistor pair with another signal. The VCO and mixer or frequency divider share common bias currents, thereby reducing power consumption. Various exemplary apparatuses and methods utilizing these techniques are disclosed.

Abstract: Aspects of a method and system for a shared GM-stage between in-phase and quadrature channels may include processing an in-phase (I) component signal for the I channel and a quadrature (Q) component signal for the Q channel via one or more shared transconductance stages in a frequency demodulator. The I channel may be isolated from the Q channel and the Q channel may be isolated from the I channel using isolation resistors. The values of the isolation resistors may be selected so as to balance the isolation and signal attenuation. A folding circuit, comprising active devices, may isolate the I channel from the Q channel. A generated voltage may be utilized to bias the folding circuit. An oscillator for the I channel may be isolated from a mixer for the Q channel and an oscillator for the Q channel may be isolated from a mixer for the I channel.

Abstract: A radio communication apparatus using a direct conversion method capable of receiving a radio signal having a predetermined frequency band. The radio communication apparatus includes: a low-noise amplifier section including one or a plurality of low-noise amplifiers receiving input of a receiving signal having a predetermined frequency band; and a mixer section including in-phase and quadrature mixers demodulating an output of the low-noise amplifier into in-phase-component and quadrature-component signals, respectively, wherein the mixer section includes a capacitor in an input section, separates the in-phase component and the quadrature component by the capacitor, and supplies the components to the corresponding in-phase and quadrature mixers, respectively.

Abstract: An RFID transceiver (200) includes a common frequency source (250), a receiving channel (230) and a transmitting channel (240). The common frequency source (250) is configured to provide a predefined intermediate frequency signal fIF, and a predefined carrier frequency signal fc. The RFID receiving channel (230) includes an upconverting mixer (232) having a first input coupled to receive the predefined intermediate frequency signal fIF, a second input coupled to receive the predefined carrier frequency signal fc, and an output, the upconverting mixer (232) operable to produce an upconverted signal at a frequency defined by fc±fIF.

Abstract: A circuit with programmable signal bandwidth is provided. The circuit includes a first charge and discharge device, a first reset device, and a first variable capacitor device. The first reset device is coupled to the first charge and discharge device, and the first variable capacitor device is coupled to the first charge and discharge device. The first reset device is controlled by a discharge enable signal and used to provide a first discharge path. When the discharge enable signal turns off the first reset device, the first variable capacitor device generates a first total equivalent capacitor to the first charge and discharge device according to n reference signals, and n is an integer greater than 0.

Abstract: An apparatus and method for processing a digital broadcast signal are provided. The method includes cutting off a noise frequency of a received digital broadcast signal and low-noise amplifying the noise cut-off signal, limiting an amplitude of the low-noise amplified signal spectrum to an amplitude of the digital broadcast signal spectrum, and cutting off a noise frequency of the amplitude limited signal spectrum and passing only a signal corresponding to a frequency band of the digital broadcast signal.

Abstract: A direct conversion multi-band TV tuner includes: a plurality of RF (radio frequency) paths for processing the RF signal and for generating a plurality of processed RF signals, respectively; and a TSC (tri-state chopper) based quadrature frequency converter for receiving one of said processed RF signals and converting the received processed RF signal into a in-phase baseband signal and a quadrature baseband signals; wherein the TSC based quadrature frequency converter operates in accordance with a first set of periodic three-state control signals and a second set of periodic three-state control signals that are approximately 90 degrees offset from the first set of periodic three-state control signals.

Abstract: In an embodiment, a method and apparatus for downconverting a received RF signal in a wireless device where differential signals from an off-chip matching network may be input to a CGCS input stage of a mixer, which downconverts the signals to baseband or some intermediate frequency. The input stage includes a pair of NMOS transistors in a common-gate configuration and a pair of PMOS transistors in a common-source configuration. A potential advantage of the CGCS input stage over the existing CGO transconductance stage configuration is that by adding a common-source stage through the PMOS differential-pair, the transconductance gain is decoupled from the high Q matching network.

Abstract: Described herein are ultra wide-band distributed RF (UWB-DRF) front-end receivers comprising composite cells distributed along transmission lines, where each composite cell comprises a low-noise amplifier (LNA) merged with a mixer. By merging the LNA and the mixer in each composite cell, the power consumption and chip area of the RF front-end is reduced. Further, the distributed architecture of the RF front-end allows it to operate over a wide bandwidth by absorbing the parasitic capacitances of the composite cells into the transmission lines of the RF-front end. Embodiments of the RF front-end provide wideband flat gain, low noise figure (NF), wideband linearity, and wideband matching at the inputs of the RF front-end. In an embodiment, a programmable resistance at the termination of the RF transmission line allows the RF front-end to trade off a few decibels of mismatch at the RF input for higher gain and lower NF.

Abstract: The second-order inter-modulation distortion, originating in a differential passive mixer core from imbalance between devices, is reduced by compensating for the mismatch or load, by means of tuning the differential output impedance at the mixer core, or the input impedance of a filter coupled to the output of the passive mixer. Compensating for the imbalance allows greater suppression of even-order harmonics in the differential structure, which reduces second-order intermodulation at the output of the mixers. The compensation is achieved by tunable resistive elements that are calibrated by a built-in self-test architecture. The calibration circuit is deactivated during receiver operation.

Abstract: The present invention is directed to a system and method of reducing frequency interference in a circuit when the harmonics of at least two frequencies could cause interference when such harmonics interact with each other. In one embodiment, a determination is made as to which harmonic could possibly support such interference, and based upon the determined harmonic, determining which combination within said determined harmonic is likely to cause the interference.

Abstract: Frequency converters include waveguides configured for a local oscillator (LO) signal, an intermediate frequency (IF) signal, and an RF signal. A multimode IF waveguide can be used for selectively coupling of an IF signal and to reduce signal contributions produced by the LO signal. Typically, the multimode waveguide is situated to that the IF signal and the LO signal propagate in different waveguide modes, and a selected one of these signals can be selectively attenuated. In some examples, a periodically stepped waveguide is used to enhance propagation of a selected waveguide mode or a lossy conductor is used to attenuate a selected waveguide mode.

Abstract: Provided are a direct sampling circuit and a receiver using a discrete time analog process and having a filter effect of a steep attenuation characteristic in a narrow-pass band without lowering a sampling rate. In a discrete time direct sampling circuit (13), the positive phase side and the inverse phase side are both sampled by a local signal for a differential current output of a differential voltage/current conversion unit (1011) and electric charge is accumulated in a charge sampling capacitor. The latest accumulated charge at the positive phase side and charge accumulated at the inverse phase side before a predetermined number of samples are combined with the charge accumulated in a history capacitor (1043) in the past. Thus, it is possible to realize equivalently high-degree FIR filter characteristic.

Abstract: A detector system for performing at least one of transmitting and receiving electromagnetic radiation at a low-terahertz frequency. The detection of electromagnetic radiation at low-terahertz frequencies can be useful in the detection of various chemicals. Preferably a detector includes a microresonant structure that is caused to resonate by electromagnetic radiation at a low-terahertz frequency. The resonance is detected by detecting an altered path of a charged particle beam.

Abstract: A time division duplexing (TDD) transmission/reception apparatus and method are provided. The TDD transmission/reception apparatus includes: a transmitter which generates a transmitted signal; an antenna which transmits the transmitted signal to an external device and receives a received signal from an external device; a receiver which restores source data by demodulating the received signal; and a polarized duplexer which has a first end connected to the transmitter and the receiver and a second end connected to the antenna and comprises an inclined surface, the inclined surface polarizing the transmitted signal and the received signal such that the directivity of the transmitted signal and the directivity of the received signal are perpendicular to each other.

Abstract: An active splitter circuit arrangement includes a first amplification module having a number of first input ports and first output ports. The first amplification module is configured to provide first stage amplification to a received input signal and produce from the amplified input signal a number of output signals, each substantially matching the input signal. Also included is a first gain control device having a number of gain input ports respectively coupled to the first output ports and a gain output port coupled to at least one of the first input ports. The first gain control device is configured to control a gain of the first amplification module. Next, a number of second amplification modules corresponding to the number of output signals has a number of second input ports respectively coupled to the first output ports.

Abstract: A method and apparatus to receive and down convert high frequency radio signals to low frequency or base band frequency is disclosed. A mixer used with a sampler produces a multi mode/multi band software enhanced radio receiver capable of supporting multiple air interfaces. The local oscillator of the disclosed mixer is harmonically related to the sampler frequency. A signal is first down converted by the mixer to a lower frequency or intermediate frequency, the signal is then sub sampled by the sub sampler, the signal is then converted to discrete time and all further processes are discrete. Successive decimation, filtering and demodulation in discrete or continuous time achieve selectivity and down conversion to base band.

Abstract: A circuit with programmable signal bandwidth is provided. The circuit includes a first charge and discharge device, a first reset device, and a first variable capacitor device. The first reset device is coupled to the first charge and discharge device, and the first variable capacitor device is coupled to the first charge and discharge device. The first reset device is controlled by a discharge enable signal and used to provide a first discharge path. When the discharge enable signal turns off the first reset device, the first variable capacitor device generates a first total equivalent capacitor to the first charge and discharge device according to n reference signals, and n is an integer greater than 0.

Abstract: An up-conversion mixer includes a first and a second hybrid couplers and a first and a second traveling-wave mixers is disclosed. The first hybrid coupler receives an input intermediate frequency (IF) signal and produces a first IF signal (IF1) and a second IF (IF2) signal, the second IF signal being 180 degree off-phase compared to the first IF signal. The first traveling-wave mixer mixes the first IF signal (IF1) and a first local oscillator (LO1) signal to produces a first radio frequency signal (RF1). The second traveling-wave mixer mixes the second IF signal (IF2) and a second local oscillator signal (LO2) to produces a second RF signal (RF2). The second hybrid coupler to combines the first RF signal and the second RF signal to produce an output RF signal. The use of the traveling-wave mixers allow for a wide bandwidth operation of the up-conversion mixer.

Abstract: An image rejection mixer including a first and a second hybrid couplers and a first and a second traveling-wave mixers is disclosed. The first hybrid coupler divides an input radio frequency (RF) signal to a first RF signal and a second RF signal, the second RF signal being in quadrature to the first RF signal. The first traveling-wave mixer mixes the first RF signal and a local oscillator (LO) signal to produces a first intermediate frequency (IF) signal. The second traveling-wave mixer mixes the second RF signal and the local oscillator signal to produces a second IF signal. The second hybrid coupler combines the first IF signal and the second IF signal to produce an upper sideband of the IF signals and a lower sideband of the IF signals. The use of the traveling-wave mixers allow for a wide bandwidth operation of the image rejection mixer.

Abstract: A mixer circuit includes a voltage-to-current converter which converts a positive phase input voltage signal and a reversed phase input voltage signal input to a first input terminal and a second input terminal into a positive phase current signal and a reversed phase current signal, a switching circuit switches over the positive phase current signal and the reversed phase current signal according to a positive phase local signal and a reversed phase local signal, and generates a positive phase output current signal and a reversed phase output current signal, and an impedance element connected between the first common terminal and the second common terminal, having a relatively high impedance to a differential-mode signal between the positive phase current signal and the reversed phase current signal, and having a relatively low impedance to a common-mode signal between the positive phase current signal and the reversed phase current signal.

Abstract: An amplifier circuit for amplifying an input signal to generate an amplifier output signal incorporates a cascaded series of reflection amplifiers arranged along a signal path and operative to amplify signals propagating in a forward direction along the signal path. The circuit is operative to counteract signal propagation in a reverse direction along the signal path, thereby hindering spontaneous oscillation from arising within the circuit. Incorporation of reflection amplifiers into the circuit enables it to provide high gain, for example 50 dB, while consuming low currents, for example, tens of microamperes. The circuit is especially suitable for use at intermediate frequencies in radio receivers such as mobile telephones.