Abstract: A dual-band printed monopole antenna is disclosed. The antenna is in a rectangular structure and comprising: a first radiating unit; a second radiating unit; a matching unit; a first matching unit; a second matching unit; a signal feed-in terminal, and a feed-in signal grounding terminal, whereby its size is effectively minified so as to meet the demand for the application of the minified modern wireless apparatus.

Abstract: A mobile terminal including an antenna device including an antenna element and a first non-feeding element, a radio-frequency unit that receives a signal from the antenna element, first and second matching circuits connected to the antenna element, a first switch that selectively connects one of the first and second matching circuits to the radio-frequency unit, a second switch that selectively grounds the first non-feeding element, an attitude-detection unit that detects an attitude of the mobile terminal, and a control unit that controls the first and second switches based on an output of the attitude-detection unit.

Abstract: A programmable antenna assembly includes a configurable antenna structure, a configurable antenna interface, and a control module. The configurable antenna structure includes a plurality of antenna elements that, in response to an antenna configuration signal, are configured elements into at least one antenna. The configurable antenna interface module is coupled to the at least one antenna and, based on an antenna interface control signal, provides at least one of an impedance matching circuit and a bandpass filter. The control module is coupled to generate the antenna configuration signal and the antenna interface control signal in accordance with a first frequency band and a second frequency band such that the at least one antenna facilitates at least one of transmitting and receiving a first RF signal within the first frequency band and facilitates at least one of transmitting and receiving a second RF signal within the second frequency band.

Abstract: A configurable antenna assembly includes an antenna structure and a configurable antenna interface. The antenna structure is operable, in a first mode, to provide a first antenna structure and a second antenna structure, wherein the first antenna structure receives an inbound radio frequency (RF) signal and the second antenna structure transmits an outbound RF signal. The configurable antenna interface is operable in the first mode to provide a first antenna interface and a second antenna interface, wherein the first antenna interface is configured in accordance with a receive adjust signal to adjust at least one of phase and amplitude of the inbound RF signal, and wherein the second antenna interface is configured in accordance with a transmit adjust signal to adjust at least one of phase and amplitude of the outbound RF signal.

Abstract: A wireless communication apparatus includes a first housing, a second housing which is openably and closably connected to the first housing through a hinge, a first conductor part which is arranged on the first housing, a second conductor and an antenna element, which are arranged on the second housing and an antenna switching part that makes the first conductor part, the second conductor part, and the antenna element serve as a dipole antenna when the first housing and the second housing are in an open state, and makes the antenna element serve as a monopole antenna when the first conductor and the second conductor are in a closed state.

Abstract: An antenna arrangement comprises a first antenna element; a second antenna element; a coupling element for electromagnetically coupling to the first antenna element and the second antenna element; and a switching mechanism, connected to the coupling element, for switching between a first electrical configuration and a second electrical configuration. When the switching mechanism is in the first electrical configuration, the coupling element has a first impedance and when the switching mechanism is in the second electrical configuration, the coupling element has a second impedance.

Abstract: An antenna assembly connectible to a radio frequency (RF) front end integrated circuit is disclosed. The antenna assembly includes a feed port connectible to a feeding line. There is a set of inner patch elements each having substantially identical first dimensions corresponding to a center resonant operating frequency, and also define perpendicular slots of predetermined lengths. The inner patch elements are in a spaced, parallel relationship. A set of outer patch elements each has substantially identical second dimensions. The inner patch elements are in a spaced, parallel and interposed relationship between the set of outer patch elements. A first electrically conductive element of the feed port is connected to a first one of the inner patch elements, and a second electrically conductive element of the feed is connected to a second one of the inner patch elements.

Abstract: A transfer unit for transferring a radio frequency signal between a classical antenna tuner and an antenna where the transfer unit comprises a switch for alternatively selecting a first direct route for the radio frequency signal between the tuner and the antenna or a second route via a reactive element; said reactive element comprising a variable serial capacitance and a shunt inductance connected to system earth; and where a control unit controls the switch and is adapted to select the first route when the frequency is above a predetermined value and otherwise select the second route. The variable serial capacitance comprises a set of capacitors organized as a set of binary weighted parallel capacitance values, and the transfer unit further comprises switches to engage or disengage each capacitor from the reactive element to increase or decrease the resulting capacitance as the radio frequency is decreased or increased.

Abstract: Output terminals (o1, o2) of a differentially excited transmitting circuit (TC) are connected through matching capacitors (MC1, MC2) to connecting terminals of the oscillatory circuit antenna (OCA) on the other side said connection terminals are directly connected to input terminals of a receiving circuit (RC). Each of the input terminals (i1, i2) of the receiving circuit (RC) is connected to an earthing terminal (m) of the integrated transceiver circuit (TRC) through a corresponding undervoltage-protection diode (UPD1, UPD2) determining a lower potential value of a received signal and a corresponding overvoltage-protection diode (OPD1, OPD2) determining an allowed upper potential value of the received signal exceeding said lower potential value by the highest possible voltage still allowable by the integrated transceiver circuit (TRC).

Abstract: An adaptive antenna neutralization network (AANN) for neutralizing coupling between a first antenna and a second antenna of a mobile terminal is disclosed. The AANN includes an array of reactive branches. Each of the reactive branches includes a reactive element and an electrically controlled switch with a control input for selectively coupling the reactive element between the first antenna and the second antenna. Also included is a switch driver having an output coupled to the control input of each electrically controlled switch, and a controller having an output for sending control signals to the switch driver to turn on or off individual ones of the electrically controlled switches in response to conditions that indicate a coupling state between the first antenna and the second antenna.

Abstract: A wireless communication terminal including an antenna that supports first and second frequency bands, an RF circuit connected to the antenna; a shunt circuit connected between a connection point of the antenna and the RF circuit, and a ground, and a control unit that controls the shunt circuit.

Abstract: There is provided a high frequency transmission module, including: a high band power amplifier amplifying power of a preset high band frequency signal; a low band power amplifier amplifying power of a preset low band frequency signal; an LC matching circuit unit matching output impedance of the low band power amplifier to impedance of an antenna switch circuit; the antenna switch circuit connecting one of a first terminal connected to an output terminal of the high band power amplifier and a second terminal connected to the LC matching circuit unit to a common terminal; and a matching/ESD protecting unit matching impedances between the antenna switch circuit and an antenna and blocking static electricity introduced from the antenna.

Abstract: A programmable antenna assembly includes a configurable antenna structure, a configurable antenna interface, and a control module. The configurable antenna structure includes a plurality of antenna elements that, in response to an antenna configuration signal, are configured elements into at least one antenna. The configurable antenna interface module is coupled to the at least one antenna and, based on an antenna interface control signal, provides at least one of an impedance matching circuit and a bandpass filter. The control module is coupled to generate the antenna configuration signal and the antenna interface control signal in accordance with a first frequency band and a second frequency band such that the at least one antenna facilitates at least one of transmitting and receiving a first RF signal within the first frequency band and facilitates at least one of transmitting and receiving a second RF signal within the second frequency band.

Abstract: An object of the invention is to stabilize the convergence operation at the automatic impedance matching time and ensure the reception quality in the convergence process in a fading environment in a radio communication apparatus which performs automatic impedance matching between an antenna and a Radio frequency section to decrease the impedance matching loss, for example, when the apparatus is brought close to a human body.

Abstract: An impedance control apparatus and method for portable mobile communication terminal is disclosed capable of accurately adjusting impedances relative to environment when the portable mobile communication terminal is being used, wherein an impedance of a first variable impedance matching part is varied to receive a reception impedance correction signal transmitted by a base station and to detect a reception strength, an impedance of the first variable impedance matching part is set by a impedance value of the largest reception strength out of the reception strengths, the portable mobile communication terminal varies the impedance of a second variable impedance matching part to transmit a transmission impedance correction signal to a base station and to allow the base station to detect the reception strength, and the impedance setting of the second variable impedance matching part is performed using the reception strength detected by the base station.

Abstract: An apparatus including: a first antenna operable in a first resonant frequency band; a second antenna operable in a second resonant frequency band; a first filter coupled to the second antenna; and a first phase shifter configured to provide the combination of at least the first filter and the second antenna with an impedance at the first resonant frequency band which substantially suppresses coupling between the first antenna and the second antenna.

Abstract: An adjustable multi-band planar antenna especially applicable in mobile terminals. The feed of the antenna can be connected by a multiple-way switch (SW) to at least two alternative points (FP1, FP2, FP3) in the radiator (310). When the feed point is changed, the resonance frequencies and thus the operating bands of the antenna change. Besides the basic dimensions of the antenna, the distance (x, y, z) of each feed point to other feed points and possible short-circuit point in the radiator, the value of the series capacitance (C31; C32; C33) belonging to a reactive circuit between the feed point and switch and the distance of the ground plane (GND) from the radiator are variables in the antenna design.

Abstract: An antenna system adapted for a communication device has a common antenna with a predetermined length, an AM matching circuit matching with the common antenna and an FM matching circuit matching with the common antenna. A switch alternatively electrically connects the common antenna to the AM matching circuit and the FM matching circuit for achieving the AM function and FM function.

Abstract: A radio frequency (RF) transceiver includes a baseband processing module, a configurable receiver section, a configurable transmitter section and a configurable antenna assembly. The baseband processing module converts outbound data into an outbound symbol stream, converts an inbound symbol stream into inbound data and generates a transmit adjust signal and a receive adjust signal. The receiver section converts an inbound RF signal into the inbound symbol stream. The transmitter section converts the outbound symbol stream into an outbound RF signal. The antenna assembly receives the inbound RF signal via a first antenna structure and transmits the outbound RF signal via a second antenna structure. The first antenna structure and/or the configurable receiver section adjusts phase and/or amplitude of the inbound RF signal in accordance with the receive adjust signal.

Abstract: An antenna includes a first antenna element and a second antenna element. The first antenna element and the second antenna element are both configured to receive signals in a first band of frequencies and in a second band of frequencies. Frequencies in the second band of frequencies are greater than frequencies in the first band of frequencies. A first impedance matching circuit, coupled to the first antenna element, includes a first plurality of filters having a first shared component. A second impedance matching circuit, coupled to the second antenna element, includes a second plurality of filters having a second shared component. A feed network circuit is coupled to the first impedance matching circuit and to the second impedance matching circuit and has a combined output corresponding to the signals received by the first antenna element and a second antenna element.

Abstract: Apparatus and methods to receive and display digital television signals are described. In one embodiment, an apparatus to receive digital television signals comprises an antenna assembly coupled to the signal processing circuitry and comprising a first antenna positioned to maximize reception in a first direction and a second antenna positioned to maximize reception in a second direction, different from the first direction, and a processor coupled to the antenna assembly and comprising a selection logic module to select an antenna to receive a digital television signal for a specific channel, and a tuning logic module to configure the antenna assembly to receive a signal via a selected antenna.

Abstract: In one embodiment, a circuit is provided that includes: an impulse generator operable to provide a pulse train; a pulse position modulator having a splitting junction configured to receive the pulse train, the pulse position modulator including a plurality of n transmission lines, wherein n is an integer, the n transmission lines being selectably coupled in parallel between the splitting junction and a combining junction, the impulse generator driving each transmission line having a unique delay such that if the transmission line is selected, each pulse received at the splitting junction is uniquely delayed into a delayed pulse, whereby if all the transmission lines are selected, each pulse received at the splitting junction is uniquely delayed into a corresponding plurality of n delayed pulses; and a controller operable to select the transmission lines responsive to received words of n bits in length, each word arranged from a first bit to an nth bit, and wherein the transmission lines are arranged from a fi

Abstract: An antenna device according to the present invention includes; a plurality of antenna elements; a line which is electro-magnetically connected to each of the antenna elements and is branched from at least one branch point in the line; and filters formed in the line between a first branch point and each of said plurality of antenna elements. Here, the first branch point is the electrically farthest branch point from each of the antenna elements among all branch points.

Abstract: In one embodiment, a wafer scale radar antenna module (WSAM) is provided that includes: a substrate; a plurality of antennas adjacent the substrate; an RF feed network adjacent the substrate, the RF feed network coupling to a distributed plurality of amplifiers integrated with the substrate, wherein the RF feed network and the distributed plurality of amplifiers are configured to form a resonant network such that if a timing signal is injected into an input port of the RF feed network, the resonant network oscillates to provide a globally synchronized RF signal to a plurality of integrated antenna circuits, wherein each integrated antenna circuits includes a corresponding subset of antennas from the plurality of antennas, and wherein each integrated antenna circuit includes a pulse shaping circuit having a plurality of selectable delay paths, each pulse shaping circuit being configured to rectify and level shift a version of the globally synchronized signal through selected ones of the selectable delay paths

Abstract: An antenna system for receiving radio waves and for operation in conjunction with a remote controller that transmits control data including gain state data. The antenna system includes an antenna that receives the radio waves and outputs a radio frequency signal and a radio frequency amplifier coupled to receive and amplify the radio frequency signal to a gain level controlled through a gain control input. A remote control receiver receives the control data and a controller is coupled to the gain control input and the remote control receiver. The controller couples the gain state data to the gain control input, thereby remotely controlling the gain level of the radio frequency amplifier. A remotely controlled antenna rotor is also taught.

Abstract: A polarization switching antenna device capable of switching a polarization without increase of an antenna installing space and also handling a variety of frequency bands is provided. A connection state of one end of a loop antenna element arranged on a side surface of a case is switched. Thus, the polarization characteristic is switched by switching selectively whether the antenna element should constitute a loop antenna or a linear antenna. Matching circuits suitable for respective characteristics are provided. The loop antenna can be fed in terms of a balanced feeding. A balanced feeding and an unbalanced feeding can be switched.

Abstract: A programmable antenna assembly includes a configurable antenna structure, a configurable antenna interface, and a control module. The configurable antenna structure includes a plurality of antenna elements that, in response to an antenna configuration signal, are configured elements into at least one antenna. The configurable antenna interface module is coupled to the at least one antenna and, based on an antenna interface control signal, provides at least one of an impedance matching circuit and a bandpass filter. The control module is coupled to generate the antenna configuration signal and the antenna interface control signal in accordance with a first frequency band and a second frequency band such that the at least one antenna facilitates at least one of transmitting and receiving a first RF signal within the first frequency band and facilitates at least one of transmitting and receiving a second RF signal within the second frequency band.

Abstract: An antenna includes a first antenna element and a second antenna element, wherein the first antenna element and the second antenna element are both configured in a hook shape. The antenna also includes a first impedance matching circuit coupled to the first antenna element, wherein the first impedance matching circuit includes a first plurality of filters and a second impedance matching circuit coupled to the second antenna element, wherein the second impedance matching circuit includes a second plurality of filters.

Abstract: The invention discloses a leaky-wave dual-antenna system comprising a transmitting antenna array and a receiving antenna array. The transmitting antenna array comprises plural first microstrips and plural corresponding first differential circuits, and each of the first differential circuit matches the corresponding first microstrip by a L-type matching network; the receiving antenna array comprises plural second microstrips and plural corresponding second differential circuits, and each of the second differential circuit matches the corresponding second microstrip by a L-type matching network. A first end and a second end of each of the first differential circuits are respectively connected to the corresponding first microstrip; a third end and a fourth end of each of the second differential circuits are respectively connected to the corresponding second microstrip.

Abstract: A planar antenna including a substrate, multiple antenna bodies and a metal layer is provided. The antenna bodies are disposed at a surface of the substrate, and the metal layer is disposed at another surface of the substrate. The metal layer has multiple slots which interlace with the antenna bodies. The antenna bodies are partially corresponding to the metal layer and used to cooperate with a communication system which can perform a multi-path transmission to send and receive electromagnetic signals for a multiple MIMO system simultaneously.

Abstract: A dual autodiplexing antenna (300) redirects power flow (303) from an unloaded antenna to a loaded antenna, thereby improving communication performance under loaded conditions. The dual autodiplexing antenna (300) includes a first antenna (101) disposed at a first end (103) of a portable two-way communication device (100). A second antenna (102) is disposed at the distal end (104) of the portable two-way communication device (100). The first antenna (101) and second antenna (102) are coupled to a transceiver (107) by a first transmission line matching circuit (201) and a second transmission line matching circuit (202), respectively. In one embodiment, the first antenna (101) is configured to primarily operate in a first bandwidth, while the second antenna (102) is configured to primarily operate in a second bandwidth. When one of the first antenna (101) or second antenna (102) is loaded, power flow (303) is redirected to the lesser loaded antenna.

Abstract: An antenna system adapted for a communication device has a common antenna with a predetermined length, an AM matching circuit matching with the common antenna and an FM matching circuit matching with the common antenna. A switch alternatively electrically connects the common antenna to the AM matching circuit and the FM matching circuit for achieving the AM function and FM function.

Abstract: In one embodiment, an impulse radio is provided that includes: a signal source operable to provide a sinusoidal source signal; a pulse shaping circuit having a plurality of selectable delay paths, the pulse shaping circuit being configured to rectify and level shift the sinusoidal source signal through selected ones of the selectable delay paths to provide an impulse signal output; a substrate; a plurality of antennas adjacent the substrate; an RF feed network adjacent the substrate and coupled to the pulse shaping circuit, the RF feed network being configured to transmit the impulse signal output to the plurality of antennas, and a distributed plurality of amplifiers integrated with the substrate and operable to amplify the impulse signal output propagated through RF feed network.

Abstract: A log-periodic antenna coupled to a channelizer is described in which matched scale constants for the antenna and the channelizer are used to achieve substantially identical coupling over each fractional bandwidth channel. Embodiments for simultaneous dual polarization operation are described as well as embodiments suited for planar lithographic fabrication.

Abstract: A polarization switching antenna device capable of switching a polarization without increase of an antenna installing space and also handling a variety of frequency bands is provided. A connection state of one end of a loop antenna element arranged on a side surface of a case is switched. Thus, the polarization characteristic is switched by switching selectively whether the antenna element should constitute a loop antenna or a linear antenna. Matching circuits suitable for respective characteristics are provided. The loop antenna can be fed in terms of a balanced feeding. A balanced feeding and an unbalanced feeding can be switched.

Abstract: An antenna includes a first antenna element and a second antenna element. The first antenna element and the second antenna element are both configured to receive signals in a first band of frequencies and in a second band of frequencies. Frequencies in the second band of frequencies are greater than frequencies in the first band of frequencies. A first impedance matching circuit, coupled to the first antenna element, includes a first plurality of filters having a first shared component. A second impedance matching circuit, coupled to the second antenna element, includes a second plurality of filters having a second shared component. A feed network circuit is coupled to the first impedance matching circuit and to the second impedance matching circuit and has a combined output corresponding to the signals received by the first antenna element and a second antenna element.

Abstract: An antenna arrangement comprising: a first antenna element; a second antenna element; a coupling element for electromagnetically coupling to the first antenna element and the second antenna element; and a switching mechanism, connected to the coupling element, for switching between a first electrical configuration and a second electrical configuration, wherein when the switching mechanism is in the first electrical configuration, the coupling element has a first impedance and when the switching mechanism is in the second electrical configuration, the coupling element has a second impedance.

Abstract: A closed-loop controlled antenna tuning unit (ATU) system includes a return loss detector connected to sample an RF signal generated by a signal source to provide a return loss signal. A matching state searching circuit is connected to receive the return loss signal and, in response, selectively store a return loss value and an impedance matching state. A central controller is connected to provide a switch control signal and apply an optimum matching state to the impedance synthesizer at the conclusion of the matching state search. An impedance synthesizer is responsive to the switch control signal for coupling a radio frequency signal and matching the impedance of an antenna to a signal source.

Abstract: A feed network device, an antenna feeder subsystem, and a base station system are provided. The feed network device comprises: two first stage couplers, two phase shifters, and two second stage couplers cascaded on a Printed Circuit Board, wherein each coupler is a multilayered dielectric broad-side coupler, and the difference of phase between an output signal at the coupling port and an output signal at the direct connection port is 90° in each multi-dielectric broad-side coupler.

Abstract: A technology which can realize a high-performance multiband operation in a compact circuit configuration and is advantageous for a wireless terminal of GSM system for which the further increase of the demands is expected in the future is provided. Provided is a multiband switch type antenna duplexer adopted in a mobile phone used in TDMA system such as the GSM system, in which the signals of respectively different first to fourth frequency bands (GSM 850, EGSM, DCS, PCS) share a single antenna, wherein switching elements such as receive filters and diodes are combined in various ways to perform the high-performance band switch with the minimum number of switching elements. The circuit of this antenna duplexer can realize not only the size reduction of the multiband switch antenna duplexer but also the size reduction and performance improvement of the wireless terminal itself.

Abstract: A multi-antenna receiving and processing circuit assembly is disclosed to include multiple antennas for receiving wireless signals, multiple pre-processing units respectively electrically connected to the antennas, a matching circuit electrically connected to the pre-processing units for matching signals from the pre-processing units into a matching signal, a post-processing unit electrically connected to the matching circuit for processing the matching signal from the matching circuit through a single intermediate frequency signal and into a plurality of audio frequency signals respective to each antenna, and an output circuit electrically connected to the post-processing unit for outputting the audio frequency signals to external audio output devices.

Abstract: A mobile terminal can include a printed circuit board with a reference voltage conductor, an antenna coupled to the first side of the printed circuit board, and a parasitic resonator coupled to the second side of the printed circuit board. More particularly, the parasitic resonator can be connected to the printed circuit board by first and second couplings, which provide first and second impedances, respectively, between the parasitic resonator and the reference voltage conductor. The impedances can be of different values, and can be provided by discrete impedance components. The resonant frequency of the parasitic resonator can be adjusted by altering the impedances of the first and second couplings.

Abstract: According to the present invention, the resistance to interference of a transmitting device, which is particularly embodied as a high frequency transmitter with a transmitter amplifier may be improved, whereby a loss-affected network, for example, in the form of a matching resistance, is coupled to the output of the transmitter amplifier, particularly in the case of low output power of the transmitter amplifier, in order to introduce an impedance-matching at the output of the transmitter amplifier. As such, the reflection of an interference signal coming from a transmitter antenna at the output of the transmitter amplifier can thus be reduced.

Abstract: An antenna device is adapted for use in at least two frequency bands, wherein the mean wave length of the higher of said frequency bands is ?. The antenna device comprises an antenna element in the form of a reed (10) mounted on a conductive support structure (20) having a projected area of less than ?2. The reed comprises a feeding portion (12) connectable to a feed device (32) and at least one impedance is connected between the reed and the conductive support. Also, the phase difference of transmitted and/or received signal waves within said at least two frequency bands over the reed is less than 120° in order to increase radiation con-ductance. A multi-band antenna device with a relatively wide upper frequency band is thereby provided.

Abstract: The invention concerns a system including a microwave generator and a rectangular guide connected with the generator. The system is adapted to operate in fundamental (H10) or transverse electrical (TE10) mode, and associated with means providing a standing wave pattern. The system also includes many power connectors arranged in the guide at zones of maximum amplitude for one of the components of the electromagnetic field for splitting the generator power. The power connectors are adjusted so that the sum of their reduced admittance levels brought to the splitter input formed by the guide is in a single unit and many sources, respectively connected to a connector of the guide, via insulating means ensuring a power transmission of the connector to the source without reflecting towards the connector and a device adapting impedance of each source, located downstream of the insulating means, between the latter and associated source.

Abstract: The present invention provides a support for an antenna. In particular, the present invention provides a substrate with conductive transition pads for a co-linear coaxial antenna array. The transition pads are constructed and arranged to properly provide power and phase shifting to the antenna array.

Abstract: A signal divider/combiner (11) and method combines first and second frequency signals received by microstrip patch antennas (58, 48). A first transmission line stub (28) blocks the second frequency signals on the first signal receiving path, and a second transmission line stub (20) blocks the first frequency signals on the second signal receiving path providing increased signal levels at a receiver input (10). In one embodiment, the transmission line stubs are open-circuit stubs and are positioned a quarter-wavelength from a combining junction (12) formed from stripline transmission lines (14, 32, 50). The transmission line stubs (28, 20) also reduce radiation of the first frequency signal by the second antenna as well as radiation of the second frequency signal by the first antenna. In one embodiment, the first and second frequency signals are the L1 and L2 signals provided by the Global Positioning System.

Abstract: A antenna arrangement comprising a multiband antenna having at least one feed point; a multiplexer, the multiplexer comprising reciprocal networks and including at least one output coupled to the at least one feed point of the multiband antenna, the multiplexer further comprising at least one input for receiving at least one signal at a first frequency, wherein the coupling between the at least one feed point and the at least one output of the multiplexer has a substantially negligible impedance.

Abstract: Signal coupling arrangements are described in which the effect of unwanted signals transferred between two antennas is compensated for. In one arrangement, a microstrip edge coupler is used as a compensation network to provide a cross-coupling path for the transfer of a compensating signal between two antenna signal paths. In another arrangement, an antenna assembly includes cross-slots which, in association with a conductive ring, provide two mutually orthogonally polarized radiation signals and connections to the conductive ring have closed spaced portions which provide compensation for and minimize the effect of unwanted mutual coupling.

Abstract: A power amplifier including: a first amplifier PA2 having an input terminal and an output terminal; a passive circuit PC3 having an input terminal and an output terminal; and a first switch SW2 having a single-pole terminal and two multi-throw terminals, one of the multi-throw terminals of the first switch SW2 being connected to the input terminal of the first amplifier PA2 and the other of the multi-throw terminals of the first switch SW2 being connected to the input terminal of the passive circuit PC3. This makes it possible to provide a power amplifier and a communication unit which can be operated with different frequencies, output powers or modulation types.