David R. Pehlke - Chapel Hill NC, US Ronald Meadows - Youngsville NC, US
Assignee:
Telefonatiebolaget L.M. Ericsson Telefonplan - Stockholm
International Classification:
H04B017/00 H04B001/04 H03C001/62
US Classification:
330127, 4551151, 4551271
Abstract:
An apparatus for monitoring a power amplifier coupled to a transmission medium includes a detector circuit, coupled to the transmission medium, that generates first and second detector signals corresponding to respective fundamental and harmonic components of a power amplifier output signal produced by the power amplifier. A comparing circuit is coupled to the detector circuit and compares the first and second detector signals. The comparing circuit, responsive to a comparison of the first and second detector signals, may generate a signal that indicates linearity of the power amplifier. In some embodiments, the detector circuit may generate the second detector signal without requiring phase information for the harmonic component. In other embodiments, a control circuit controls linearity of the power amplifier responsive to comparison of the first and second detector signals, for example, by controlling power amplifier bias and/or input signal level based on the comparison. Related methods are also discussed.
Semiconductor devices having a plurality of unit cells connected in parallel are provided. The unit cells each have a gate finger with a gate pitch between adjacent ones of the gate fingers. The gate pitch is non-uniform in a predetermined pattern.
A power amplifier circuit for a radio transceiver has a linear mode amplifier and a saturated (nonlinear) mode amplifier, a diplex matching circuit coupled to the linear mode amplifier for impedance matching and for separating transmitted signals in a plurality of frequency bands, a low pass matching circuit coupled to the output of the saturated mode amplifier and means for selectably placing the power amplifier circuit in a linear mode for or a saturated mode, corresponding to digital and analog modes of operation of the cellular telephone, respectively. In linear or digital mode, the linear amplifier is biased in the on state and the saturated mode amplifier may be biased in the off state. Similarly, in the saturated or analog mode of operation, the saturated mode amplifier is biased in the on state and the linear amplifier may be biased in the off state. The amplifier circuit may include a switch or circuit, coupled to an output of the diplex matching circuit and the output of the low pass matching circuit, for selectably coupling the first diplex matching circuit output or the low pass matching circuit output to an output line when the amplifier circuit is selectably placed in linear mode or saturated mode, respectively.
Ronald D. Boesch - Morrisville NC Ronald C. Meadows - Youngsville NC
Assignee:
Ericsson Inc. - Research Triangle Park NC
International Classification:
H04B 138 H04M 100
US Classification:
455553
Abstract:
A power amplifier circuit has a driver amplifier stage including a low band driver amplifier and a high band driver amplifier. A final amplifier stage includes a linear mode amplifier for amplifying digitally modulated signals and a saturated (nonlinear) mode amplifier for amplifying frequency modulated (analog) signals. A switching network interconnects the driver amplifier stage and the final amplifier stage. Depending on the desired mode of operation, an appropriate driver amplifier can be coupled to an appropriate final amplifier to most effectively and efficiently amplify analog or digital RF signals in either of a plurality of frequency bands. A diplex matching circuit is coupled to the linear mode final amplifier for impedance matching and for separating D-AMPS (800 MHz band) and PCS (1900 MHz band) digital signals. A power impedance matching circuit is coupled to the output of the saturated mode final amplifier.
Dual-Band, Dual-Mode Power Amplifier With Reduced Power Loss
Ronald D. Boesch - Morrisville NC Ronald C. Meadows - Youngsville NC
Assignee:
Ericsson Inc. - Research Triangle Park NC
International Classification:
H04Q 732
US Classification:
455 74
Abstract:
A power amplifier circuit has a driver amplifier stage including a low band driver amplifier and a high band driver amplifier. A final amplifier stage includes a linear mode amplifier for amplifying digitally modulated signals and a saturated (nonlinear) mode amplifier for amplifying frequency modulated (analog) signals. A switching network interconnects the driver amplifier stage and the final amplifier stage. Depending on the desired mode of operation, an appropriate driver amplifier can be coupled to an appropriate final amplifier to most effectively and efficiently amplify analog or digital RF signals in either of a plurality of frequency bands. A matching circuit is coupled to the linear mode final amplifier for impedance matching and for separating D-AMPS (800 MHz band) and PCS (1900 MHz band) digital signals. A power impedance matching circuit is coupled to the output of the saturated mode final amplifier. In one embodiment, an isolator is coupled to the output of one or more of the low band or high band outputs of the duplex matching circuit.
Lisa Maxwell, Vickie Lawhorn, Robert Billings, Mary Cox, Brenda Honaker, Carla Bailey, Brenda Billings, Lucy Mills, Lindell Hatcher, Teresa Tolliver, Clayton Cadle