Abstract: The present application provides a multiband power amplification apparatus. The first input terminal receives a signal in a frequency band f1; the second input terminal receives a signal in a frequency band f2. The first adjustment module adjusts a first channel of signal and then outputs an adjusted first channel of signal to the first adder. The second adjustment module adjusts a third channel of signal and then outputs an adjusted third channel of signal to the first adder. The first adder converges the signal adjusted by the second adjustment module and the signal output by the first adjustment module and then outputs a converged signal to a first digital-to-analog converter. The second adder converges a second channel of signal and a fourth channel of signal and then outputs a converged signal to a second digital-to-analog converter.

Abstract: A power amplifier includes a clamping circuit configured to provide a clamped voltage from a power supply; an amplifier pair having first inputs coupled to the clamping circuit, second inputs and an output for providing an amplified signal; and a biasing circuit coupled between the clamping circuit and the second inputs. The biasing circuit is configured to adjust input bias voltages of the amplifier pair such that the output of the amplifier pair varies proportionally to a change of the power supply.

Abstract: An automobile audio system having at least two near-field speakers located close to an intended position of a listener's head is configured by determining a first binaural filter that causes sound produced by each of the near-field speakers to have characteristics at the intended position of the listener's head of sound produced by a sound source located at a first designated position other than the actual locations of the near-field speakers, determining an up-mixing rule to generate at least three component channel signals from an input audio signal having at least two channels, and configuring the audio system to, determine a first binaural signal corresponding to a combination of the component channel signals originating at the first designated position, and filter the first binaural signal using the first binaural filter and to output the filtered signals using the near-field speakers.

Abstract: An apparatus is provided for load modulating a power amplifier that is configured to output a multiband radio frequency signal comprising at least a first frequency band and a second frequency band. The apparatus comprises a multiplexer (31) coupled to receive a multiband radio frequency signal from the output of a power amplifier, and configured to separate the multiband radio frequency signal into first and second frequency band signals. A first load modulator circuit (33i) is provided in a first branch, the first load modulator circuit coupled to receive the first frequency band signal, and configured to load modulate the first frequency band signal. A second load modulator circuit (332) is provided in a second branch, the second load modulator circuit coupled to receive the second frequency band signal, and configured to load modulate the second frequency band signal.

Abstract: An integrated circuit architecture and circuitry is defined by a die structure with a plurality of exposed conductive pads arranged in a grid of rows and columns. The die structure has a first operating frequency region with a first transmit and receive chain, and a second operating frequency region with a second transmit chain and a second receive chain. There is a shared region of the die structure defined by an overlapping segment of the first operating frequency region and the second operating frequency region with a shared power supply input conductive pad connected to the first transmit chain, the second transmit chain, the first receive chain, and the second receive chain, and a shared power detection output conductive pad connected to the first transmit chain and the second transmit chain.

Abstract: An analog signal transfer system includes a transmission apparatus including a variable compressor that variably compresses input signals exponentially according to the amplitudes of the input signals; and a reception apparatus including a variable expander that variably expands the compressed signals exponentially according to the amplitudes of the compressed signals.

Abstract: A semiconductor device including: a filter circuit to subdivide and output the received signal as a first signal with a relatively low frequency and a second signal with a relatively high frequency; a first channel containing a photocoupler to convey the first signal output from the filter circuit; a second channel containing an isolator to convey the second signal from the filter circuit; and a signal synthesis circuit to sum and output the first signal conveyed by way of a first channel and a second signal conveyed by way of a second channel.

Abstract: A pickup device for an electric instrument may include at least one permanent magnet to detect vibrations from the electric instrument's strings. The pickup device may further include at least one coil within a magnetic field of the permanent magnet. The coil may be coupled to one or more of a plurality of selectable filters. The pickup device may be an integrated assembly and fittable within a standard-sized pickup cavity on the electric instrument.

Abstract: A multiple-path, configurable, radio-frequency (RF) circuit is provided, including: a first amplifier path amplify a first RF signal to generate a first amplified signal; a second amplifier path configured to amplify a second RF signal to generate a second amplified signal; a corrective input matching circuit, configured to change first input-impedance-matching properties of the first amplifier path, and to change second input-impedance-matching properties of the second amplifier path; a first isolation element configured to selectively ground an input node of the second amplifier path; a second isolation element configured to selectively ground an output node of the second amplifier path; and a third isolation element connected between the first and second amplifier paths, configured to selectively isolate the corrective input matching circuit from first and second input nodes of the first and second amplifier paths, respectively, or connect the corrective input matching circuit to the first and second input

Abstract: A semiconductor device including: a filter circuit to subdivide and output the received signal as a first signal with a relatively low frequency and a second signal with a relatively high frequency; a first channel containing a photocoupler to convey the first signal output from the filter circuit; a second channel containing an isolator to convey the second signal from the filter circuit; and a signal synthesis circuit to sum and output the first signal conveyed by way of a first channel and a second signal conveyed by way of a second channel.

Abstract: A dynamic feed-forward OPAMP-based circuit is provided. A first amplifying stage amplifies a pair of input differential signals to provide a pair of intermediate differential signals. A second amplifying stage amplifies the pair of intermediate differential signals to provide a pair of output differential signals. A first capacitor is coupled to a non-inverting input terminal of the first amplifying stage. A second capacitor is coupled to an inverting input terminal of the first amplifying stage. A feed-forward transconductance stage is coupled between the first and second capacitors and the second amplifying stage. The first and second capacitors and the feed-forward stage form a high-frequency path with a first gain curve, and the first amplifying stage and the second amplifying stage form a high-gain path with a second gain curve. The operational amplifier provides an open-loop gain according to the first and second gain curves.

Abstract: A dual band amplifier is provided comprising a first matching circuit disposed in a first radiofrequency path between an input port and a first amplifier and a second matching circuit disposed in a second radiofrequency path between the input port and a second amplifier. The first matching circuit transforms a first input impedance of the first amplifier to a predetermined input port impedance when the radiofrequency signal is in a first frequency range and transmits the first input impedance to the input port when the radiofrequency signal is in the second frequency range. The second matching circuit transforms the second input impedance to the input port impedance when the input signal is in the second frequency range and transmits the second input impedance to the input port when the radiofrequency signal is in the first frequency range.

Abstract: A bidirectional matching network is disclosed. In an exemplary embodiment, an apparatus includes a first matching circuit connected in a first signal path between a node and a first amplifier, the first matching circuit configured to translate an off-state impedance of the first amplifier to a first translated off-state impedance. The apparatus also includes a second matching circuit connected in a second signal path between the node and a second amplifier. The second matching circuit configured to translate an off-state impedance of the second amplifier to a second translated off-state impedance. The second translated off-state impedance is configured to reduce power loss associated with a first signal flowing in the first signal path and the first translated off-state impedance is configured to reduce power loss associated with a second signal flowing in the second signal path.

Abstract: A power amplifier circuit (DIPPA), comprising a driver stage (DR) which is applicable to provide a preamplified driver signal (S_DR) dependent on a predetermined transmit signal. The power amplifier circuit (DIPPA) comprises also a frequency selector (DIP) which is electrically coupled to the driver stage (DR) and which is applicable to separate the driver signal (S_DR) into a first and second signal (S—1, S—2). The first signal (S—1) is associated to a first predetermined and the second signal (S—2) is associated to a second predetermined frequency band. The power amplifier circuit (DIPPA) comprises at least a first and second power amplifier stage (PA1, PA2). The first and second power amplifier stage (PA1, PA2) are electrically coupled to the frequency selector (DIP). The first and second power amplifier stage (PA1, PA2) is operable to provide a first and second amplified signal (S_A1, S—2), respectively, dependent on the first and second signal (S—1, S—2), respectively.

Abstract: Embodiments provide a radio frequency (RF) power amplifier (PA) circuit having a high-power mode and a low-power mode. The RF PA circuit may include a high-power amplifier to provide an amplified RF signal on a first path, and a low-power amplifier to provide an amplified RF signal on a second path. The first path and second path may intersect at a junction node. A switch may be coupled between the low-power amplifier and the junction node to switch the circuit between the high-power mode and the low-power mode. A matching circuit may be coupled on the second path to match an output impedance of the low-power amplifier to a junction impedance of the junction node at a fundamental frequency of the RF signal, and to present an open circuit at a third harmonic of the RF signal. The matching circuit may facilitate high efficiency for the RF PA circuit.

Abstract: A home use sound reproduction system for Hi-fi, with digital signal transfer from a playback unit via a control unit to one or more active loudspeakers, each including or arranged beside an amplifier unit. The control unit is arranged to control sound parameters and send both a digital sound information signal and a power signal for powering the amplifier units, and to superimpose the single ended or differential digital signal together with the power signal on at least one common lead in a cable.

Abstract: A combiner for a Doherty amplifier includes, on and in a dielectric substrate, a carrier input terminal, a peak input terminal, an output terminal, a combining point for combining an output signal from the carrier amplifier and an output signal from the peak amplifier, a first ?/4 line connected between the carrier input terminal and the combining point, a second ?/4 line connected between the combining point and the output terminal, and a first directional coupler. The first directional coupler includes a third ?/4 line electromagnetically coupled to one, to be monitored, of the first ?/4 line and the second ?/4 line.

Abstract: Provided is a multi-band amplifier and a method of amplifying a multi-band. The multi-band amplifier includes a wireless signal input terminal into which a first frequency band signal and a second frequency band signal are input, a first impedance matching part connected to the wireless signal input terminal and configured to match an input impedance in a first frequency band, a second impedance matching part connected to the wireless signal input terminal and configured to match an input impedance in a second frequency band, a common source amplifier to which the first impedance matching part and the second impedance matching part, and a common gate amplifier connected to the common source amplifier. Accordingly, performance degradation can be reduced in comparison with a conventional amplifier, broadband amplification as well as narrow band amplification can be performed, and an amplification gain can be adjusted.

Abstract: The disclosure relates to an enhanced Doherty amplifier that provides significant performance improvements over conventional Doherty amplifiers. The enhanced Doherty amplifier includes a power splitter, combining node, a carrier path, and a peaking path. The power splitter is configured to receive an input signal and split the input signal into a carrier signal provided at a carrier splitter output and a peaking signal provided at a peaking splitter output. The carrier path includes carrier power amplifier circuitry, a carrier input network coupled between the carrier splitter output and the carrier power amplifier circuitry, and a carrier output network coupled between the carrier power amplifier circuitry and the Doherty combining node.

Abstract: Duplex communications are facilitated. In connection with various example embodiments, current sources are used to drive transistor-based circuits coupled across a first resistive circuit, to send signals on a communications medium. While driving the transistor-based circuits, the current sources are used to drive reference transistor-based circuits coupled across a second resistive circuit. A differential output signal based upon a power-related value across the first resistive circuit, less a power-related value across the second resistive circuit. This differential output signal characterizes a power-related value corresponding to a received signal on the communications medium, as gleaned from a total signal corresponding to both transmitted and received signals, less a signal corresponding to the transmitted signal.

Abstract: A power amplifier (20) for operation in at least a first and a second frequency band, wherein a center frequency f2 of the second frequency band is higher than a center frequency f1 of the first frequency band, is disclosed. The power amplifier (20) comprises a transistor (35) for amplifying an input signal of the power amplifier (20) and an output coupling network (45) for connecting the power amplifier to a resistive load (55). The output coupling network (45) is operatively connected to an output terminal (40) of the transistor (35), has an output terminal (50) for connection to said resistive load (55), and is configured such that, when the power amplifier (20) is connected to said resistive load (55), the power amplifier (20) is arranged to operate in class F for frequencies in one of the first and the second frequency bands, and operate in inverse class F for frequencies in the other one of the first and the second frequency band.

Abstract: A system includes a plurality of band pass filters to pass signals in separated frequency bands to or from an antenna. A matching network provides characteristic impedances. The system is designed such that the configuration of the matching network and BPFs provides high impedance to the band pass filters for those routing paths other than the band pass path as these routing paths do not transmit or receive the signals at this particular pass band. The system is further designed such that the configuration of the matching network and BPFs provides minimal insertion loss for the band pass path of for transmission and receipt of signals at this particular pass band, where each routing path has a corresponding pass band. The matching network is for coupling to an amplifier, when frequency separation is needed at the output of the amplifier to the BPFs. In one embodiment an impedance network tunes the impedance by using varying length transmission lines.

Abstract: The LINC modulator includes: a separator that generates a plurality of constant envelope signals from a source signal; a plurality of arms through which the plurality of the constant envelope signals are passed, wherein each arm includes a filter that compares frequencies of components of the constant envelope signals with a threshold frequency to generate a first signal including a first frequency part of the source signal, the first frequency part being composed of frequencies lower than a predetermined frequency; a processor that generates a second signal including a second frequency part of the source signal whose frequencies are different from the first frequency part and performs a frequency signal distortion of the second signal to generate a distorted signal; and a quadrature modulator that multiplies the first and distorted signals to reconstruct the constant envelope signals.

Abstract: A method for amplifier volume specification and control, the method includes: applying an initial volume level to an amplifier; determining one or more of: which A/V component has been selected for use, which channel or frequency is being outputted, and the type of outputted A/V content; modifying the initial amplifier volume level with one or more stored volume level settings in response to at least one of the following: the determined A/V component in use; the selected channel and frequency outputted, and the type of outputted A/V content; wherein the one or more stored volume level settings include: received volume level settings for audio/video (A/V) components; received volume level settings for selected channels and frequencies that are outputted by the A/V components; and received volume level settings for A/V content.

Abstract: Systems and methods are provided for a broadband, closed-loop RF transmitter for multi-band applications that employs a single RF path to service multiple bands of operation. Embodiments of the present disclosure implement a broadband impedance matching module, which avoids the need for several costly and complex narrow-band matching networks. In an embodiment, the broadband impedance matching module includes concentric, mutually-coupled inductors. By adding this broadband impedance matching functionality, delay is significantly reduced because a single path can be used to service multiple bands.

Abstract: Power amplifying systems and modules and components therein are designed based on CRLH structures, providing high efficiency and linearity.

Abstract: Existing multi-band/multi-mode (MB/MM) power amplifiers (PAs) use separate signal paths for the different covered frequency bands. This results in a large degree of hardware duplication and to a large die size and cost. Solutions that achieve hardware sharing between the different signal paths of MB/MM PAs are shown. Such sharing includes bias circuit and bypass capacitors sharing, as well as sharing front-end stages and the output stage of the PA. Signal multiplexing may be realized in the transmitter or at the PA front-end while the signal de-multiplexing can be realized either in the PA output stage or at the front-end of the output stage. Such circuits can be applied with saturated and linear MB/MM PAs with adjacent or non-adjacent bands.

Abstract: A dual band amplifier is provided comprising a first matching circuit disposed in a first radiofrequency path between an input port and a first amplifier and a second matching circuit disposed in a second radiofrequency path between the input port and a second amplifier. The first matching circuit transforms a first input impedance of the first amplifier to a predetermined input port impedance when the radiofrequency signal is in a first frequency range and transmits the first input impedance to the input port when the radiofrequency signal is in the second frequency range. The second matching circuit transforms the second input impedance to the input port impedance when the input signal is in the second frequency range and transmits the second input impedance to the input port when the radiofrequency signal is in the first frequency range.

Abstract: A first signal path has one or a plurality of coils arranged in series, the coils being connected to the output of a first amplifier. A second signal path has the same number of coils as the coils of the first signal path, the coils being arranged in series and connected to the output of a second amplifier. Coupling paths have capacitors and couple the first signal path and the second signal path at both ends of the corresponding coils on the first signal path and the second signal path. A SW controlling unit switches a switch to a contact when a signal is input from the first amplifier and switches the switch to a contact when a signal is input from the second amplifier.

Abstract: There is disclosed a microphone, a circuit, and a method. A microphone capsule may include an electret microphone and a field effect transistor (FET). A floating DC voltage source may have a first end connected to a drain terminal of the electret microphone capsule and a second end. A load resistor may be connected between the second end of the floating DC voltage source and a source terminal of the electret microphone capsule. A voltage follower may have an output connected to the source terminal of the electret microphone capsule and the first end of the floating DC voltage source. A coupling capacitor may couple an audio signal from the source terminal of the electret microphone capsule to an input of the voltage follower.

Abstract: Power amplifying systems and modules and components therein are designed based on CRLH structures, providing high efficiency and linearity.

Abstract: Methods and systems for vector combining power amplification are disclosed herein. In one embodiment, a plurality of signals is individually amplified, then summed to form a desired time-varying complex envelope signal. Phase and/or frequency characteristics of one or more of the signals are controlled to provide the desired phase, frequency, and/or amplitude characteristics of the desired time-varying complex envelope signal. In another embodiment, a time-varying complex envelope signal is decomposed into a plurality of constant envelope constituent signals. The constituent signals are amplified equally or substantially equally, and then summed to construct an amplified version of the original time-varying envelope signal. Embodiments also perform frequency up-conversion.

Abstract: A method and apparatus is provided for linearizing the output of a non-linear device, such as a power amplifier. The input signal to the non-linear device is predistorted based on a predistortion model to compensate for distortion introduced by a non-linear device. A wideband feedback signal is generated from the output signal of the non-linear device, and the wideband feedback signal is filtered to generate two or more narrowband distortion signals with predetermined frequencies corresponding to anticipated distortion components in the output signal. Model parameters of the predistortion model are adapted based on the narrowband distortion signals.

Abstract: In accordance with an embodiment, a method of amplifying a plurality of frequency bands includes amplifying a first frequency band and a second frequency band with a main amplifier, amplifying the first frequency band with a first peaking amplifier, amplifying the second frequency band with a second peaking amplifier, and simultaneously load modulating an output of the main amplifier with an output of the first peaking amplifier and with an output of the second peaking amplifier.

Abstract: In accordance with an embodiment, a method of amplifying a plurality of frequency bands includes amplifying a first frequency band and a second frequency band with a main amplifier, amplifying the first frequency band with a first peaking amplifier, amplifying the second frequency band with a second peaking amplifier, and simultaneously load modulating an output of the main amplifier with an output of the first peaking amplifier and with an output of the second peaking amplifier.

Abstract: Power amplifying systems and modules and components therein are designed based on CRLH structures, providing high efficiency and linearity.

Abstract: The LINC modulator includes: a separator that generates a plurality of constant envelope signals from a source signal; a plurality of arms through which the plurality of the constant envelope signals are passed, wherein each arm includes a filter that compares frequencies of components of the constant envelope signals with a threshold frequency to generate a first signal including a first frequency part of the source signal, the first frequency part being composed of frequencies lower than a predetermined frequency; a processor that generates a second signal including a second frequency part of the source signal whose frequencies are different from the first frequency part and performs a frequency signal distortion of the second signal to generate a distorted signal; and a quadrature modulator that multiplies the first and distorted signals to reconstruct the constant envelope signals.

Abstract: Provided are a first filter 63a and a second filter 63b each having a pass band in the range of a frequency band that is obtained by, for example, substantially bisecting a frequency band of f1 to f4. In that case, the regions of the first filter 63a and the second filter 63b partially overlap with each other with the center frequency f5 interposed therebetween. In practice, even if the division is not bisection, a configuration is adopted in which a frequency region of the wider band (the first frequency band 61a) closer to a second frequency band 61b side is covered by the second filter 63b. Accordingly, it is possible to suppress the influence of load fluctuation in a multiband-compatible radio communication device.

Abstract: The RF power amplifier circuit including multiple amplification stages has a previous-stage amplifier, a next-stage amplifier and a controller. The previous-stage amplifier responds to an RF transmission input signal. The next-stage amplifier responds to an amplification signal output by the previous-stage amplifier. In response to an output-power-control voltage, the controller controls the former- and next-stage amplifiers in quiescent current and gain. In response to the output-power-control voltage, the quiescent current and gain of the previous-stage amplifier are continuously changed according to a first continuous function, whereas those of the next-stage amplifier are continuously changed according to a second continuous function. The second continuous function is higher than the first continuous function by at least one in degree. The RF power amplifier circuit brings about the effect that the drop of the power added efficiency in low and middle power modes is relieved.

Abstract: Methods and systems for vector combining power amplification are disclosed herein. In one embodiment, a plurality of signals are individually amplified, then summed to form a desired time-varying complex envelope signal. Phase and/or frequency characteristics of one or more of the signals are controlled to provide the desired phase, frequency, and/or amplitude characteristics of the desired time-varying complex envelope signal. In another embodiment, a time-varying complex envelope signal is decomposed into a plurality of constant envelope constituent signals. The constituent signals are amplified equally or substantially equally, and then summed to construct an amplified version of the original time-varying envelope signal. Embodiments also perform frequency up-conversion.

Abstract: A power amplifier circuit (DIPPA), comprising a driver stage (DR) which is applicable to provide a preamplified driver signal (S_DR) dependent on a predetermined transmit signal. The power amplifier circuit (DIPPA) comprises also a frequency selector (DIP) which is electrically coupled to the driver stage (DR) and which is applicable to separate the driver signal (S_DR) into a first and second signal (S—1, S—2). The first signal (S—1) is associated to a first predetermined and the second signal (S—2) is associated to a second predetermined frequency band. The power amplifier circuit (DIPPA) comprises at least a first and second power amplifier stage (PA1, PA2). The first and second power amplifier stage (PA1, PA2) are electrically coupled to the frequency selector (DIP). The first and second power amplifier stage (PA1, PA2) is operable to provide a first and second amplified signal (S_A1, S—2), respectively, dependent on the first and second signal (S—1, S—2), respectively.

Abstract: A directional dual distributed coupler including: a first conductive line between first and second ports, intended to convey a signal to be transmitted in a first frequency band; a second conductive line coupled to the first one; a third conductive line between third and fourth ports, intended to convey a signal to be transmitted in a greater frequency band than the first one; a fourth conductive line coupled to the third one; and at least one diplexer connecting, on the side of the second and fourth ports, the respective ends of the second and fourth lines to a fifth port.

Abstract: A power amplification apparatus and method provide for controlling envelope modulation of a Radio Frequency (RF) signal. The power amplification apparatus includes a linear amplifier configured to receive an input signal to be amplified, and generate a linear output signal for compensating for a current ripple of an amplified signal and a switch control signal having a current obtained by dividing the linear output signal by a predetermined ratio. The power amplification apparatus also includes a switching amplifier configured to receive the switch control signal through a multi-mode resistor having a variable resistance, and generate the amplified signal. The variable resistance of the multi-mode resistor determines a switching frequency representing an operating speed of the switching amplifier, and is adjusted according to a communication mode of the input signal.

Abstract: A wireless communication device includes an RF transceiver configured to up convert a base band signal to a transmitting RF signal, a configurable matrix power amplifier circuit configured to amplify the transmitting RF signal to produce an amplified RF signal, and an antenna configured to transmit a wireless signal in response to the amplified RF signal.

Abstract: Current-feedback instrumentation amplifiers that include dynamic element matching for the input transconductance amplifiers by periodically swapping the transconductance amplifiers between the instrumentation amplifier input and the feedback input. The instrumentation amplifiers may include a gain error reduction loop, which loop corrects differences in the gains of the input transconductance amplifiers and eliminates the ripple in the instrumentation amplifier output caused by the dynamic element matching. If chopper stabilization is used, the amplifiers may also include an offset reduction loop. Various embodiments are disclosed.

Abstract: The present disclosure relates to a quadrature RF power amplifier (PA) architecture that uses a single-ended interface to couple a non-quadrature PA path to a quadrature PA path, which may be coupled to an antenna via an antenna port. The quadrature nature of the quadrature PA path provides tolerance for changes in antenna loading conditions. An RF splitter in the quadrature PA path presents a relatively stable input impedance, which is predominantly resistive, to the non-quadrature PA path over a wide frequency range, thereby substantially isolating the non-quadrature PA path from changes in the antenna loading conditions. Further, the input impedance substantially establishes a load line slope of a feeder PA stage in the non-quadrature PA path, thereby simplifying the quadrature RF PA architecture. One embodiment of the quadrature RF PA architecture uses two separate PA paths, either of which may incorporate a combined non-quadrature and quadrature PA architecture.

Abstract: Power amplifying systems and modules and components therein are designed based on CRLH structures, providing high efficiency and linearity.

Abstract: According to one embodiment, a wide band power amplifier is provided, which includes: a first amplifier unit that has a first center frequency; a second amplifier unit that is arranged in parallel to the first amplifier unit, and has a second center frequency higher than the first center frequency; a power divider connected to an input of the first amplifier unit and an input of the second amplifier unit; and a first power combiner connected to an output of the first amplifier unit and an output of the second amplifier unit.

Abstract: An attenuator circuit includes a high-frequency circuit path to produce an attenuated first signal; a low-frequency circuit path to produce an attenuated second signal, where the attenuated first signal has a higher frequency than the attenuated second signal; and a transistor that includes a control input. The control input is configured to receive the attenuated second signal to bias the transistor for passage of the attenuated first signal and the attenuated second signal.

Abstract: A transmission apparatus and a method thereof in a mobile terminal are provided. More particularly, an apparatus and a method for securing a space of a mobile terminal and reducing manufacturing costs by integrating power amplifying units into one module in the mobile terminal that supports a multi-mode are provided. The power amplifier of a mobile terminal includes a first amplifying unit and a second amplifying unit. The first amplifying unit defines a frequency of a GSM quad band as a low frequency band and a high frequency band, and then amplifies a signal of the low frequency band of the GSM quad band. The second amplifying unit amplifies a signal of the high frequency band of the GSM quad band and a signal of a TD-SCDMA band.