Abstract: A method and apparatus for efficient power amplification of a wideband signal with a correspondingly wide modulation bandwidth includes splitting means (110), class-G amplifier/modulator (120), and power amplifier (130). Three-level class-G amplifier/modulator (200, FIG. 2) comprises operational amplifier circuits (215, 225), three-state selection circuit (209), switch driver circuit (219), drive signal routing circuit (216), power stage circuit (217), and filter network (218). Multiple power stages are multiplexed based on the amplitude of the envelope signal.

Abstract: A method and apparatus for efficient power amplification of a wideband signal with a correspondingly wide modulation bandwidth includes splitting means (110), class-G amplifier/modulator (120), and power amplifier (130). Three-level class-G amplifier/modulator (200, FIG. 2) comprises operational amplifier circuits (215, 225), three-state selection circuit (209), switch driver circuit (219), drive signal routing circuit (216), power stage circuit (217), and filter network (218). Multiple power stages are multiplexed based on the amplitude of the envelope signal.

Abstract: According to the present disclosure, an inrush current limiter comprises an input (190) for connection to a supply voltage, an output (202) for connection to a load, a current limiter circuit (102), a current bypass circuit (106), and a charge status circuit (104). During the initial charging of capacitors, the current limiter circuit (102) senses a large inrush current and limits the current to a predetermined quantity. The current bypass circuit (106) is switched off during the initial charging of the capacitors. When the capacitors are charged to substantially equal the input voltage, the current bypass circuit (106) is switched on to provide a low-resistance path for the supply current to pass through. In addition, the charge status circuit (104) operates to indicate the supply voltage.

Abstract: A radio frequency signal (FIG. 2, 205) is sampled and the sample is conveyed to a video detector (220). The detected envelope amplitude is sent to an envelope tracking circuit (280), a comparator (230), and an envelope tracking and gate biasing circuit (240). Based on the instantaneous value of the envelope amplitude, the comparator (230) selects one of the available supply voltages (340) via switch drivers (270). The selected one of the available supply voltages (340) is adjusted by the envelope tracking circuit (280) and the resulting voltage output (282) is supplied to the drains of the power amplifiers (390), thus enabling operation near saturation. As the instantaneous value of the envelope amplitude increases, the comparator (230) selects higher supply voltages (340) which increases the voltage conveyed to the power amplifiers (390), thereby increasing their power output.

Abstract: A radio frequency EER-type power amplifier is described in which pulse width modulation is utilized. Input rf signals are split into phase and amplitude paths by a delay line (210). The phase path is coupled to a power amplifier (260). The amplitude path includes an envelope detector (220) coupled to a class S amplifier (270). The class S amplifier is coupled to the power amplifier (260) via a transmission line implemented low pass filter (290). The low pass filter uses strip line transmission lines (410, 510) which may utilize magnetic material (520, 720) to enhance the operation of the low pass filter. The class S amplifier and a transmission line filter provide an amplified, high fidelity replica of the input rf signal.

Abstract: A method (300, 400), device (100, 200), phone (200) and base station (200) provide an efficient tracking power converter for variable signals. The tracking power converter includes a feedforward feedback control unit that is coupled to receive a reference signal and to receive at least one feedback signal and is used for determining an optimal control signal in accordance with a predetermined scheme, a pulse width modulation unit that is coupled to the feedforward feedback control unit and is used for modifying a duty ratio to provide a switching signal, and a power converter that is coupled to the pulse width modulation unit and to a power source and is used for providing the dynamic variable output signal.

Abstract: A method and apparatus for efficient power amplification of a wideband signal with a correspondingly wide modulation bandwidth includes an envelope detector (220), an interleaved class S modulator (270), and a power amplifier (260). The interleaved class S modulator (270) amplifies includes multiple channels (272) which each include a portion of a class S modulator. Each class S modulator has a duty cycle and time offset associated therewith. The duty cycles of the channels (272) can be the same with the time offsets different, or the duty cycles can also be different. For an interleaved class S modulator with N channels (272), the slew rate increases by as much as N, and the output ripple decreases by as much as N.sup.2.

Abstract: A method and apparatus for efficient power amplification over a wide dynamic range and for a number of modulation formats includes a carrier amplifier (30) and a peaking amplifier (40). The carrier amplifier (30) operates with a bias generated by an envelope amplifier (80) which amplifies the envelope of an input signal as generated by an envelope detector (70). The peaking amplifier (40) operates with a fixed bias. The outputs of the carrier amplifier (30) and the peaking amplifier (40) are combined using an impedance transforming network (50). Envelope amplifier (80) can be turned on for high efficiency low power level operation, or it can be turned off for standard Doherty-type operation.

Abstract: A class-S modulator (5) receives an input signal (10) having envelope information and pulse-width modulates the input signal (10) using a reference waveform (26) from a waveform generator (25). The envelope becomes a pulse-width modulated signal is level-shifted and amplified through a pre-driver (40). A driver (50) controls switches (60, 70) which drive an output (80) into a low-pass filter (90) wherein the envelope is restored to the amplified signal for driving a power amplifier in a wide-band transceiver.

Abstract: A method and apparatus for efficiently amplifying input signals includes multiple amplifiers (20, 30). Each amplifier receives a signal from a power divider (12) where the input signal is split with substantially equal phase. Each amplifier drives a load (40) through a parallel coupled line pair (26, 36). The parallel coupled line pairs are preferably implemented in micro-strip or strip line technology. Each amplifier includes gate bias inputs (24, 34) and drain bias inputs (22, 32). The gate bias inputs can be biased equally and the drain bias inputs can be biased equally, resulting in a parallel, power combined, amplifier configuration. Alternately, the drain bias inputs can be staggered, or the gate bias inputs can be staggered to increase efficiency.

Abstract: A method and apparatus for efficient power amplification of a wideband signal with a correspondingly wide modulation bandwidth includes an envelope detector (220), an multi-stage class S modulator (270), and a power amplifier (260). The multi-stage class S modulator (270) includes multiple stages (480), where each stage includes a pair of switching transistors (430, 440) and a capacitor (450). The capacitor (450) supplies the inrush current requirements of the stage (480) so that filtering at the switching frequency is substantially provided within the stage (480). Multiple stages (480) are included on a single semiconductor substrate resulting in higher switching frequencies, higher modulation bandwidths, and lower external filtering requirements.

Abstract: A method and apparatus for efficient power amplification of a modulated signal includes an envelope detector (220), an multi-output class S modulator (270), a driver amplifier (250), and a power amplifier (260). The multi-output class S modulator (270) amplifies the envelope of the input signal and generates a primary amplified envelope signal and at least one offset amplified envelope signal. The offset amplified envelope signal is used to modulate the driver amplifier (250), and the primary amplified envelope signal is used to modulate the power amplifier (260).

Abstract: A method and apparatus for efficient power amplification of a high dynamic range signal includes an envelope detector (220), a multi-range modulator (270), and a power amplifier (260). The multi-range modulator (270) efficiently amplifies the envelope of the input signal by selecting a power source as a function of the amplitude of the input signal. Multi-range modulator (200) produces a pulsewidth modulated signal with a duty cycle and an amplitude. When the amplitude of the input signal rises above a reference, the duty cycle and the amplitude are modified so as to keep the multi-range modulator in an operating region of high efficiency.

Abstract: An rf transmitter (319) used with a single cell battery (101) includes a voltage boost circuit (211) integral with a class S amplifier (290). An rf signal to be amplified is separated into its envelope (amplitude) and phase components. The phase component is applied to the input of a power amplifier (260). The envelope is applied to a pulse width modulator (275) which is used to modulate the voltage supplied to the power amplifier (260). The pulse width modulator (275) controls electronic switches (285, 286) which are disposed between the single cell battery (101) and the primary of a step up transformer (211). The secondary of the transformer (211) is coupled to supply voltage to the power amplifier (260). In this manner, the class S amplifier is powered directly from the single cell battery, via a the transformer (211), and power consumption is substantially reduced due to the switching operation of the switches (285, 286).

Abstract: A method and apparatus for efficient power amplification with low distortion includes an envelope detector (220), a difference amplifier (130), an envelope amplifier (270), and a power amplifier (260). A feedback path is provided from the output through a second envelope detector (120) to the difference amplifier (130). The feedback circuit operates on the bandwidth of the envelope of the RF signal rather than at the RF bandwidth. An envelope amplifier (270) includes a difference amplifier (272), a pulsewidth modulator (275), a driver (280), switching transistors (285), a low pass filter (290), and a voltage scaler (292). A feedback path within the envelope amplifier reduces the time delay introduced by low pass filter (290). The combined feedback loops work together to reduce distortion and lower intermodulation products.

Abstract: A method and apparatus for efficient power amplification with low phase distortion includes an envelope detector (30), a scaling amplifier (40), a driver amplifier (50), and a power amplifier (60). The scaling amplifier (40), in response to the envelope signal from the envelope detector (30), generates a bias signal which causes predistortion in the driver amplifier (50). The predistortion in the driver amplifier (50) compensates for phase distortion in the driver amplifier (50) and the power amplifier (60), resulting in low phase distortion output. An EER-type amplifier (200) with high efficiency utilizes the predistortion of a driver amplifier (250) to compensate for phase distortion in the driver amplifier (250) and a power amplifier (260).

Abstract: A power supply (10) including a virtual resistor. The power supply (10) includes (i) a power stage (11) having an input (12) for accepting unregulated power, an output (14) for providing regulated power, a control input (13) and a current sense output (16); (ii) a control circuit (15) including an error amplifier (19) having an inverting input coupled to the output (14) and an output coupled to the control input (13); and (iii) a virtual resistance generator (25) having an input coupled to the output of the error amplifier (19) and an output coupled to a non inverting input of the error amplifier (19). The virtual resistance generator (25) is for supplying a reference voltage (27) to the control circuit (15) such that a voltage present at the output for providing regulated power (14) as a function of current leaving the output for providing regulated power (14) provides an output virtual resistance.

Abstract: A time-delay compensating class-S modulator (4) receives an input signal (10) having RF envelope information and generates a delay error signal (18) from a comparison to an attenuated output signal. The delay error signal (18) is pulse-width modulated using a reference waveform (26) from a waveform generator (25). The envelope becomes a pulse-width modulated signal and is level-shifted and amplified through a pre-driver (40). A driver (50) controls switches (60, 70) which drive an output (80) into a low-pass filter (90) wherein the envelope is restored to the amplified signal for driving a power amplifier in a wide-band transceiver.

Abstract: A method and apparatus for efficient power amplification with low distortion includes a surface acoustic wave delay line (210), an envelope detector (220), an envelope amplifier (270), and a power amplifier (260). An envelope amplifier (270) includes a pulsewidth modulator (275), a driver (280), switching transistors (285), and a low pass filter (290). The surface acoustic wave delay line (210) functions to balance the delay of the envelope and the carrier of the signal to be amplified. The use of the surface acoustic wave delay line (210) obviates the need for a separate delay line in the phase path of the amplifier.

Abstract: A pulse load averaging power converter (10) provides low duty cycle, high amplitude power pulses while drawing substantially constant power from a power source. A voltage peak detector (70) provides a pulse width modulator PWM (20) with a feedback signal proportional to the peak of the output voltage. A regulated switching power converter (200) utilizes pulse load averaging power converter (10). The resulting power converter provides high current, low duty cycle power pulses, while maintaining a substantially constant current draw on a battery (230). An individual subscriber unit (400) which operates in a cellular communications system, utilizes pulse load averaging power converter (10) to prolong battery life.