Abstract: A multi-band RF power amplifier circuit fabricated using GaN technology includes a RF power amplifier coupled to a multi-band RF switch without an intervening impedance matching network between the RF power amplifier and the multi-band RF switch. The multi-band RF switch includes a plurality of Unit HEMT cells. In one IC package, the RF power amplifier, the multi-band RF switch, a controller for controlling the switch and all connection therebetween are totally contained within the IC package. In another IC package, the RF power amplifier and the multi-band RF switch are disposed on a single substrate.

Abstract: A multi-band RF power amplifier circuit fabricated using GaN technology includes a RF power amplifier coupled to a multi-band RF switch without an intervening impedance matching network between the RF power amplifier and the multi-band RF switch. The multi-band RF switch includes a plurality of Unit HEMT cells. In one IC package, the RF power amplifier, the multi-band RF switch, a controller for controlling the switch and all connection therebetween are totally contained within the IC package. In another IC package, the RF power amplifier and the multi-band RF switch are disposed on a single substrate.

Abstract: A method and apparatus for a power amplifier module is described. The module includes a power amplifier and a power supply modulator coupled to the power amplifier. In addition, the module includes an inverter coupled between the power amplifier and the power supply modulator. The inverter provides a predistorted signal to the power amplifier to cancel distortion in the power amplifier provided by the power supply modulator. In addition, the module can include a driver coupled between the power amplifier and the inverter wherein the driver supplies the predistorted signal to the power amplifier.

Abstract: A method and apparatus for a power amplifier module is described. The module includes a power amplifier and a power supply modulator coupled to the power amplifier. In addition, the module includes an inverter coupled between the power amplifier and the power supply modulator. The inverter provides a predistorted signal to the power amplifier to cancel distortion in the power amplifier provided by the power supply modulator. In addition, the module can include a driver coupled between the power amplifier and the inverter wherein the driver supplies the predistorted signal to the power amplifier.

Abstract: A supply voltage to a power amplifier is controlled. A signal at a single point in a power amplifier is detected. A signal parameter is determined for the detected signal. The signal parameter is compared to at least one predetermined limit. This comparison result is used to determine whether to adjust a supply voltage to the power amplifier. The signal parameter is, for example, an average power or a peak-to-average power ratio.

Abstract: If the mobile station (101) locates a peer it will request network metadata and may obtain location related services or service lists. The mobile station (101) negotiates with one of more peers (103) to share the work load of background scanning for network services. After successful negotiation, any peers in the “discovery net” will report or advertise to each other of any newly discovered networks, or networks to which connectivity has been lost. Since the various mobile stations may, when powered on, scan periodically for network changes, the metadata stored on the mobile station (101) will be dynamic and will change periodically upon travels and/or encounters with additional peers. Because the peers (103) may also possess location information, the mobile station (101) may additionally adjust its scan to prioritize services advertised by those members of peers (103) that are located most proximate to the mobile station (101).

Abstract: A circuit and method for protecting a radio frequency power amplifier against peak drain voltage. A detector circuit has an input connected to a drain of a power transistor of an amplification stage of the power amplifier to detect a peak drain voltage therefrom. The detector circuit outputs a protection signal when the detected peak drain voltage exceeds a predetermined reference level. A shutdown circuit is coupled to the detector circuit and inputs the protection signal therefrom. The protection signal is used to remove a gate bias of at least one amplification stage of the power amplifier. High frequency components are used in the detector and protection circuits to immediately reduce the drain voltage from one or more of the amplification stages.

Abstract: A circuit and method for protecting a radio frequency power amplifier against peak drain voltage. A detector circuit has an input connected to a drain of a power transistor of an amplification stage of the power amplifier to detect a peak drain voltage therefrom. The detector circuit outputs a protection signal when the detected peak drain voltage exceeds a predetermined reference level. A shutdown circuit is coupled to the detector circuit and inputs the protection signal therefrom. The protection signal is used to remove a gate bias of at least one amplification stage of the power amplifier. High frequency components are used in the detector and protection circuits to immediately reduce the drain voltage from one or more of the amplification stages.

Abstract: A circuit is provided, having a feed forward linear power amplifier configured with two or more error correction loops (225–235, 255–265). Each of the error correction loops includes a band pass filter (237, 257). Each of the band pass filters (237, 257) is tuned to a different frequency range. A controllable frequency oscillator (220) can be coupled to an input of the error correction loops. A controller sweeps the frequency of the controllable frequency oscillator over the frequency range corresponding to each of the band pass filters (237, 257).

Abstract: Apparatus and methods are described for biasing amplifiers with multiple outputs. A semiconductor die may include a reference Field Effect Transistor (FET) integrated on the semiconductor die and coupled to an amplifier integrated on the semiconductor die. A voltage offset circuit may also be integrated on the semiconductor die for determining the voltage needed to operate the amplifier.

Abstract: A redundant linear power amplifier (LPA) system is provided for minimizing the loss of power output during malfunction conditions. The redundant LPA system includes a transmitter (102) with redundant LPA units (110, 112) for providing spatial combining redundancy and transmitter polarization diversity. Each LPA unit (110, 112) receives an input signal. The output from one of the LPA units (110) is connected to an antenna (120) and the output from the second LPA unit (112) is phase shifted (117) and then connected to a second antenna (122). Alternatively, the outputs from the LPA units (110, 112) are input into a quadrature hybrid (126) and the output (128) from a first port (131) of the quadrature hybrid (126) is connected to the first antenna (120) and the output (130) from a second quadrature hybrid port (133) is phase shifted (117) and connected to the second antenna (122).

Abstract: In a linear amplification system, an input signal is amplified to produce a substantially linear amplified output signal without causing significant intermodulation distortion or spectral growth. An envelope detector determines an envelope detector voltage from the input signal. A tracking power supply determines a supply voltage based on the envelope detector voltage. An input signal conditioner determines, in response to the supply voltage, a corresponding phase adjustment and a corresponding gain adjustment and modifies the input signal using the corresponding phase adjustment and the corresponding gain adjustment to produce a conditioned input signal. A power amplifier operates using the supply voltage and amplifies the conditioned input signal to produce the amplified output signal.

Abstract: An optimal operating point of an envelope tracking amplification system that includes a radio frequency (RF) power amplifier having an RF amplifying element is determined based on an application to the RF power amplifier of a supply voltage that is less than the rated voltage of the RF amplifying element.

Abstract: An envelope tracking amplification system that includes an envelope tracking power supply (ETPS) amplifies a radio frequency (RF) signal to produce a linearized amplified signal. The envelope tracking amplification system samples the RF signal to produce a sampled RF signal. The ETPS produces a control signal based on an instantaneous magnitude of the sampled RF signal and further based on an average magnitude of the sampled RF signal, produces multiple supply voltages, and, based on the control signal, couples a supply voltage of the multiple supply voltages to an output of the EPTS to produce an output supply voltage. The envelope tracking amplification system then amplifies the RF signal based on the output supply voltage to produce a highly linear amplified signal.

Abstract: An envelope tracking amplification system that includes an envelope tracking power supply (ETPS) amplifies a radio frequency (RF) signal to produce a linearized amplified signal. The envelope tracking amplification system samples the RF signal to produce a sampled RF signal. The ETPS produces a control signal based on an instantaneous magnitude of the sampled RF signal and further based on an average magnitude of the sampled RF signal, produces multiple supply voltages, and, based on the control signal, couples a supply voltage of the multiple supply voltages to an output of the EPTS to produce an output supply voltage. The envelope tracking amplification system then amplifies the RF signal based on the output supply voltage to produce a highly linear amplified signal.

Abstract: A wideband linear amplification system amplifies an input signal to produce an amplified output signal. An envelope detector determines an envelope detector signal based on the input signal. An amplifier bias controller produces multiple control signals based on the envelope detector signal. A predistortion signal loop modifies the input signal, using a companion amplifier stage, based on a first control signal of the multiple control signals to produce a predistorted input signal that includes a distortion component introduced by the companion amplifier stage. A main amplifier stage amplifies the predistorted input signal to produce the amplified output signal based on a second control signal of the multiple control signals, wherein the distortion component of the predistorted input signal at least partially cancels a distortion component introduced to the amplified output signal by the main amplifier stage.

Abstract: A wideband linear amplification system amplifies an input signal to produce an amplified output signal. An envelope detector determines an envelope detector signal based on the input signal. An amplifier bias controller produces multiple control signals based on the envelope detector signal. A predistortion signal loop modifies the input signal, using a companion amplifier stage, based on a first control signal of the multiple control signals to produce a predistorted input signal that includes a distortion component introduced by the companion amplifier stage. A main amplifier stage amplifies the predistorted input signal to produce the amplified output signal based on a second control signal of the multiple control signals, wherein the distortion component of the predistorted input signal at least partially cancels a distortion component introduced to the amplified output signal by the main amplifier stage.

Abstract: An apparatus (150), system (100) and method (400-440) are illustrated for power amplification of an input signal to produce a substantially linear amplified output signal, for broadband wireless applications such as 3G cellular and broadband CDMA systems, without causing significant intermodulation distortion or spectral growth. The preferred system (100) embodiment includes an envelope detector (110) to determine an envelope detector voltage from the input signal; a tracking power supply (120) to determine a supply voltage, preferably as a substantially quantized replica of the envelope detector voltage; an input signal conditioner (150) to determine, in response to the supply voltage, a corresponding phase adjustment and a corresponding gain adjustment, and to modify the input signal using the corresponding phase adjustment and the corresponding gain adjustment to produce a conditioned input signal for power amplification.

Abstract: A feedforward amplifier network (42) generates a fixed offset frequency swept pilot tone (46) over at least the same frequency band as an input signal (40). The fixed offset frequency swept pilot tone (46) is a function of a variable frequency reference signal (52) and a fixed pilot tone clock signal (54). A mixer arrangement (66 and 70), as opposed to a phase lock loop arrangement, helps ensure that the fixed frequency offset can be generated over the swept range. In addition, the feedforward amplifier network (42) incorporates a delay (58) which is added to the variable frequency reference signal (52) and used by a pilot tone detector (57) so that the pilot tone generator (44) and pilot tone detector (57) are in synchronization over narrow bands to accommodate pilot tone detection in the presence of code division multiple access channels that are relatively close together.

Abstract: An error corrected amplifier circuit (100) for use in a radio frequency system is provided. The error corrected amplifier circuit (100) includes a first pilot modulation stage (101) and a second pilot modulation stage (103). The first pilot modulation stage (101) creates a first amplified signal (129) having an error component and a first error signal (134) indicative of the error component. The second pilot modulation stage (103) receives the first amplified signal (129) and the error signal (134) and generates an error reduced amplified signal (158).