Patent•
Apparatus and method for envelope tracking power amplifier in wireless communication system
07 Sep 2010-
TL;DR: In this paper, an apparatus and method for amplifying a Transmit (Tx) signal according to an Envelope Tacking (ET) scheme in a wireless communication system are provided.
Abstract: An apparatus and method for amplifying a Transmit (Tx) signal according to an Envelope Tacking (ET) scheme in a wireless communication system are provided. A transmitting end apparatus includes an envelope gain controller for controlling a gain of a digital baseband Tx signal in accordance with power control, a detector for detecting an envelope signal from the digital baseband Tx signal whose gain is controlled, and for shaping on the envelope signal, a first Digital to Analog Converter (DAC) for converting the shaped envelope signal into an analog signal, and an envelope modulator for generating a drain bias of a power amplifier that amplifies a Radio Frequency (RF) Tx signal by using the analog envelope signal. Accordingly, a digital-based ET scheme is implemented, and by using a plurality of shaping tables, efficiency of the ET scheme can be maximized in a transmitting end that uses power control.
Citations
More filters
Patent•
07 Feb 2012TL;DR: In this article, an open loop envelope tracking system calibration technique and circuitry is proposed, where an envelope tracker power converter generates a modulated power amplifier supply voltage for the radio frequency power amplifier based on a control signal derived from the modulated signal.
Abstract: An open loop envelope tracking system calibration technique and circuitry are proposed. A radio frequency power amplifier receives a modulated signal. An envelope tracker power converter generates a modulated power amplifier supply voltage for the radio frequency power amplifier based on a control signal derived from the modulated signal. A first output power and a second output power of the radio frequency power amplifier are measured when the control signal is respectively delayed by a first delay period and a second delay period. A sensitivity of the output power of the radio frequency power amplifier is near a maximum near the first delay period and the second delay period. The first delay period and/or the second delay period are adjusted until the first output power substantially equals the second output power. The first delay period and the second delay period are used to obtain a calibrated fine tuning delay offset.
96 citations
Patent•
19 Apr 2011TL;DR: In this article, a pseudo-envelope follower power management system was used to manage the power delivered to a linear RF power amplifier, which is used to control a linear power amplifier.
Abstract: Embodiments disclosed in the detailed description relate to a pseudo-envelope follower power management system used to manage the power delivered to a linear RF power amplifier.
89 citations
Patent•
05 Nov 2013TL;DR: In this article, the transceiver circuitry regulates a modulated power supply voltage, which is used by the radio frequency power amplifier to provide power for amplification, based on the difference between the target output power from the RFP amplifier and the measured output power of the RF power amplifier.
Abstract: Configuration-feedback circuitry and transceiver circuitry are disclosed. The configuration-feedback circuitry regulates an output power from a radio frequency power amplifier based on a difference between a target output power from the radio frequency power amplifier and a measured output power from the radio frequency power amplifier. The transceiver circuitry regulates a modulated power supply voltage, which is used by the radio frequency power amplifier to provide power for amplification, based on the difference between the target output power from the radio frequency power amplifier and the measured output power from the radio frequency power amplifier.
82 citations
Patent•
27 Dec 2012TL;DR: In this paper, a direct current (DC)-DC converter, which includes a parallel amplifier, a radio frequency (RF) trap, and a switching supply, is disclosed, and the switching supply includes switching circuitry and a first inductive element.
Abstract: A direct current (DC)-DC converter, which includes a parallel amplifier, a radio frequency (RF) trap, and a switching supply, is disclosed. The switching supply includes switching circuitry and a first inductive element. The parallel amplifier has a feedback input and a parallel amplifier output. The switching circuitry has a switching circuitry output. The first inductive element is coupled between the switching circuitry output and the feedback input. The RF trap is coupled between the parallel amplifier output and a ground.
69 citations
Patent•
05 Nov 2013TL;DR: In this paper, a switch mode power supply converter and a parallel amplifier are described, where the switch mode converter is coupled to a modulated power supply output and the parallel amplifier has a parallel output coupled to the modulated output.
Abstract: A switch mode power supply converter and a parallel amplifier are disclosed. The switch mode power supply converter is coupled to a modulated power supply output and the parallel amplifier has a parallel amplifier output coupled to the modulated power supply output. Further, the parallel amplifier has a group of output stages, such that each output stage is directly coupled to the parallel amplifier output and each output stage receives a separate supply voltage.
68 citations
References
More filters
Patent•
29 Jan 2008TL;DR: In this article, an envelope tracking (ET) method for controlling the delivery of power to radio frequency power amplifiers (RFPAs) is described. But the system is not suitable for the use of a power amplifier.
Abstract: Envelope tracking (ET) methods and systems for controlling the delivery of power to radio frequency power amplifiers (RFPAs). An exemplary ET system includes an RFPA and a wide bandwidth capable and power efficient envelope modulator that includes a first power supplying apparatus and a second power supplying apparatus. The first power supplying apparatus includes a switch-mode converter and a regulator. The first mode converter is operable to dynamically step down a fixed power supply voltage according to amplitude variations in an envelope signal received by the regulator, and use the resulting dynamic power supply signal to power the regulator. The second power supplying apparatus is connected in parallel with the first power supplying apparatus. Depending on a power of an output signal to be generated at an output of the power amplifier, power is supplied to the power amplifier from either or both of the first and second power supplying apparatuses.
204 citations
Patent•
11 Jan 2000TL;DR: A highly efficient radio frequency (RF) transmitter provides both wide bandwidth and an extended power control range as mentioned in this paper, which is useful in wireless communications to increase both handset talk time and battery life.
Abstract: A highly efficient radio frequency (RF) transmitter provides both wide bandwidth and an extended power control range. The RF transmitter includes stage switching, bias adjustment, and drain supply modulation. These components are used to provide fine and coarse power control and EER envelope fluctuations. The RF transmitter is useful in wireless communications to increase both handset talk time and battery life.
170 citations
Patent•
04 May 2007TL;DR: In this paper, a non-linear filter was used to preserve the rise time of a peak in a waveform of an envelope but lengthen the peak duration of the peak.
Abstract: The invention relates to optimizing efficiency of a power amplifier of a transmitter. In a solution according to the invention a detected envelope (306) of an input signal of the power amplifier is filtered with a non-linear filter (307) that substantially preserves a rise time of a peak in a waveform of the envelope but lengthens a temporal duration of the peak. A filtered envelope is used as an input quantity (308) for a control system that controls a supply voltage of the power amplifier. For the control system it is easier to react to peaks of the filtered envelope than to the peaks of the envelope because the temporal duration of the peaks of the filtered envelope is longer than that of the peaks of the envelope.
99 citations
Patent•
18 Apr 2002TL;DR: In this paper, a method and device for improving the efficiency of an envelope tracking transmitter in which a power amplifier for coupling modulated signals in a carrier frequency to an antenna for transmission is presented.
Abstract: A method and device for improving the efficiency of an envelope tracking transmitter in which a power amplifier for coupling modulated signals in a carrier frequency to an antenna for transmission. The transmitter comprises a power supply for providing a supply voltage to the power amplifier, and a computation means for providing a waveform indicative of the envelope of the modulated signal to the power supply in order to modify the supply voltage. A lower limit is imposed to the waveform so that the supply voltage to the power supply is always greater than a predetermined value. Moreover, when information is transmitted in times slots which are started and ended by ramp periods, a constant signal, based on the root-mean-square value of the waveform, is used to modify the waveform so that the supply voltage to the power amplifier includes a constant voltage level in the ramp periods.
93 citations
Patent•
23 Jul 2003TL;DR: In this article, an amplification system and method is provided that reduces peaks associated with an input signal, and provides correction, in one or more spectral bands, to signal distortion and out-of-band emissions that result from the peak reduction.
Abstract: An amplification system and method is provided that reduces peaks associated with an input signal, and provides correction, in one or more spectral bands, to signal distortion and out-of-band emissions that result from the peak reduction. The correction signal that removes signal distortion and OOB emissions associated with the peak reduction can be calculated or electronically derived. The correction signal can be combined with the peak reduced signal prior to or after amplification of the peak reduced input signal.
92 citations