Envelope Elimination Research Articles

Diagnosis of sensitive leaf types and spectral segments during maize heading stage under simulated copper stress environment in mining areas

ABSTRACT This paper designed CSSDM (Copper Stress Spectral Diagnosis Method) from the perspective of frequency domain, combined with time-frequency analysis, to obtain sensitive leaf types and spectral segments under heavy metal copper stress, providing technical support for heavy metal monitoring in crops. Firstly, the hyperspectral reflectance data of maize leaves under copper stress were subjected to DD (Double Differentiation) and EE (Envelope Elimination), and transformed into the frequency domain. The d6 (Daubechies wavelet 6-layer) decomposition was performed using time-frequency analysis methods. Then, based on the signal anomaly points, wavelet high value points and DDEE (Double Differentiation Envelope Elimination) curve high value points, the SRVP (Spectral Reflectance Variation Parameters) of maize leaves are defined. Finally, by examining the correlation between spectral reflectance variation parameters and heavy metal content in maize leaves, we aim to explore the leaf types and spectral segments that are sensitive to copper pollution. The results showed that CSSDM can efficiently enhance weak information in maize leaves and accurately locate the spectral anomaly caused by heavy metal copper stress, with the anomaly range concentrated within 350 nm−800 nm. Spectral reflectance variation parameters can quantitatively measure the spectral anomalies of maize leaves under heavy metal copper stress. Under different copper stress gradients, maize new leaves exhibit sensitive leaf types, with sensitive spectral segments including Blue Edges, Green Peaks, Yellow Edges and Red Valleys.

A review of different structures of power amplifiers to improve linearity and efficiency

<p>This review paper presents a comprehensive study of commonly used power amplifier (PA) structures. In recent years, with the development of modern wireless telecommunications and their dramatic challenges, new requirements are needed. In addition, some applications, like cell phones and tablets, for example, need new considerations, especially in terms of power consumption. Also, linearity is another major factor in designing a PA. Furthermore, fabrication technologies such as complementary metal-oxide semiconductors (CMOS), silicon on insulators (SOI), gallium nitride (GaN), gallium arsenide (GaAs), etc. play a crucial role in terms of power consumption. Therefore, it is necessary for PAs to meet these considerations. This paper reviews design considerations, fabrication technologies, and common PA structures, including envelope tracking (ET), envelope elimination and restoration (EER), Doherty, linear amplification with nonlinear components (LINC), feedback, and feedforward linearization techniques with their pros and cons. This review focuses on the significant achievements, techniques, structures, and characteristics of each. Also, this review focuses on the significant achievements, techniques, structures, and characteristics of each. Also, this paper tries to provide a brief overview of the various methods with the advantages and disadvantages of each. This review paper tries to make readers familiar with common structures so that readers know the advantages and disadvantages of each and choose the desired structure based on their priorities.</p>

EFFICIENCY ANALYSIS OF SWITCHING CONVERTER-MODULATOR

The article discusses methods of highly efficient linear RF power amplifier and transmitter design for future 5G/6G networks. Based on a consideration of various known methods for constructing high-efficiency power amplifiers, the prospects of developments using the envelope elimination and restoration (EER, or Kahn method) and envelope tracking (ET) method are substantiated. The prospects for implementing PWM switching converter-modulator for these methods are assessed. Based on the evaluation calculations performed, it is shown that this structure can potentially be used as an EEP/ET modulator for a number of 5G/6G applications and will have advantages over structures using class AB amplification.

Theoretical Comparison of Different Envelope Elimination and Restoration Transmitter PWM Modulator Configurations to Expand the Possible Antenna Mismatch

The main characteristics of high-efficiency switching-mode solid-state power amplifiers with envelope elimination and restoration (EER) methods depend on all their elements. In this article, we study the influence of the types and parameters of the envelope path low-pass filters (LPFs) on the EER transmitter out-of-band emissions. This article presents for the first time an analysis of EER transmitter operation where the output impedance of the PWM modulator is not equal to zero, as usual (with a one-sided loaded LPF), but is matched with the low-pass filter and the load (with a double-sided loaded LPF). Theoretical comparisons of EER transmitters’ out-of-band emissions were carried out with four envelope path LPF configurations (one-sided and double-sided loaded LPFs with a smooth and sharp transition, respectively), for both the nominal load (broadband antenna) and resonant antennas with a limited bandwidth. The analysis showed that for the case of transmitter operation on a resonant antenna with a limited bandwidth, the preferable option was the use of a sixth-order double-sided loaded LPF with a smooth transition. The use of the proposed modulator configuration allowed the transmitter to operate on an antenna with VSWR = 1.07 at the edges of the transmitted signal band with a minimum LPF bandwidth equal to 5.8 bands of the amplified signal. This could significantly expand its application capabilities and allow one to reduce the PWM clock frequency and increase efficiency.

Methods of reducing antenna bandwidth requirements for envelope elimination and restoration transmitter

The task of radio transmitting path efficiency increasing is relevant both for stationary high-power applications and for autonomous low-power devices. The highest efficiency can be achieved in switching operating modes (classes D, E, F). For the amplification of modern spectrally efficient broadcast and telecommunication signals with variable amplitude, for example, with OFDM, the use of switching operating modes is possible only with the use of "synthetic" amplification methods. The most promising for application can be considered Envelope Elimination and Restoration (EER) method, which is successfully used in the field of high-power broadcasting in the LF, MF and HF bands, and is the object of a large number of studies aimed at expanding its scope. Transmitting devices of radio communication and broadcasting systems in some cases are forced to work with an electrically short antenna. However, when operating with OFDM signals to a narrow-band load, high-efficiency EER transmitters require matching with an antenna circuit with an SWR of at least 1.05 in the signal frequency band. Thus, the task of antenna bandwidth requirements reducing for EER transmitter is relevant. To solve it, a simulation model was previously developed and verified to study the operation of EER switching RF power amplifiers for a narrow-band load. With its help, the dependence of output signal distortion level on the envelope path LPF parameters was studied. This article proposes and analyzes hardware circuit solutions aimed at reducing the transmitter sensitivity to antenna bandwidth. The analysis of hardware methods for reducing the EER transmitter sensitivity to the resonant antenna SWR (passband) showed the following: 1. The damping circuit, together with a double-sided loaded envelope path LPF, allows you to reduce antenna SWR requirements to a maximum value of 1.22, while the allowable antenna bandwidth can be reduced to five signal bands. 2. The high-pass filter diplexer proposed in this paper, together with a double-sided loaded envelope path LPF, makes it possible to reduce antenna SWR requirements to a maximum value of 1.47, and the allowable antenna bandwidth can be reduced to 2.5 signal bands. The disadvantages of this method include the need, depending on the antenna used, for individual design and manufacture of high-pass filter diplexers installed in the low-frequency path of each amplifying cell of the transmitter. To expand the range of antennas used, it is possible to switch capacitors of the high-pass filter diplexer from a set of 2 ... 3 pieces. Data on the production of transmitters with the proposed HPF diplexer has not been found to date. 3. Multi-phase PWM when using a 2nd order unilaterally loaded low-pass filter and installing 2nd harmonic rejectors of the operating frequency in the cells of the RF path allows you to work on antennas with a bandwidth of up to half the signal bandwidth. Restrictions on the antenna bandwidth and its SWR are imposed only by the uneven antenna frequency response in the transmitted signal band. The disadvantages of this method include the need to install narrow-band rejectors that block the power supply circuit of each RF cell in terms of the 2nd harmonic, which makes such a transmitter a custom product for a fixed operating frequency. 4. The most promising solution should be considered the use of a high-pass filter diplexer, which allows relatively simple means to expand the permissible SWR of a narrow-band antenna in the signal band from the initial value of 1.05 to 1.47.

Зависимость уровня искажений выходного сигнала передатчика современных телекоммуникационных сигналов с разделением составляющих от параметров фильтра тракта огибающей

The article investigates the dependence of the envelope elimination and restoration (EER) transmitter out-of-band emissions on the parameters of its envelope path LPF. LPFs of the sixth order with the Cauer structure, having the same degree of clock frequency unwanted products suppression, unilaterally and bilaterally loaded, and optimized LPFs with a smooth transition of the frequency response from the passband to the stopband are considered. It is shown that when the transmitter is operating at a nominal load (broadband antenna), a sharp transition from the passband to the stopband in the envelope path LPF leads to an increase in out-of-band emissions that are separated from the center frequency of the transmitter by the LPF cutoff frequency. The minimum envelope path allowable bandwidth is at least 5 transmitted signal bandwidths when using a Cauer-type LPF with a standard approximation and at least 3.5 bandwidths for an optimized LPF with a smooth transition. For the case of a transmitter operating on a resonant antenna with a limited bandwidth, the dependences of the minimum envelope path filter required bandwidth on the antenna bandwidth and the VSWR value at the edges of the amplified signal band are revealed. It is shown that the use of two-sided loaded filters in the envelope path allows the transmitter to work on antennas with half the bandwidth and reduce the antenna SWR requirements from 1.03 to 1.07. The use of smooth transition filters allows you to reduce the minimum required bandwidth of the LPF by 20% compared to standard filters. The most preferable is the use of a two-sided loaded LPF of the 6th order with a smooth transition, which ensures the operation of the transmitter to the antenna with VSWR = 1.07 at the edges of the transmitted signal band with a minimum LPF bandwidth equal to 5.8 signal bands.

Broadband and Efficient Envelope Amplifier for Envelope Elimination and Restoration/Envelope Tracking Higher-Efficiency Power Amplifiers

Increasing the efficiency of transmitters, as the largest consumers of energy, is relevant for any wireless communication devices. For higher efficiency, a number of methods are used, including envelope tracking and envelope elimination and restoration. Increasing the bandwidth of used frequencies requires expanding envelope modulators bandwidth up to 250-500 MHz or more. The possibility of using amplifiers with input signal quantization (AISQ), as an alternative to the most common hybrid envelope tracking modulators, is considered. An approach has been developed for optimizing AISQ characteristics according to the criterion of minimum loss when amplifying modern telecommunication signals with Rayleigh envelope distribution. The optimal quantization levels are determined and the energy characteristics of AISQ are calculated. AISQ loss power is shown to decrease by 1.66 times with two-level quantization, by 2.4 times with three-level quantization, and by a factor of 3.0-3.7 for four-five quantization levels compared to a class B amplifier. With these parameters, AISQ becomes competitive with respect to hybrid envelope tracking modulators but does not have electromagnetic interference from the pulse width modulation (PWM) path.

ПОСТРОЕНИЕ МОЩНЫХ ШИРОКОПОЛОСНЫХ УСИЛИТЕЛЕЙ ПОСТОЯННОГО ТОКА МОДУЛЯЦИОННОГО ТРАКТА ПЕРЕДАТЧИКОВ С РАЗДЕЛЬНЫМ УСИЛЕНИЕМ СОСТАВЛЯЮЩИХ

Increasing transmission path efficiency, as the largest consumer of electricity, is relevant for any wireless communication devices, digital television, and radio broadcasting. A number of methods are used to improve efficiency, including Envelope Tracking (ET) and Envelope Elimination and Restoration (EER, or Kahn method). Increasing the bandwidth of used frequencies in 5G radio systems requires expanding the modulation path DC amplifiers bandwidth to 250…500 MHz or more. The possibility of using amplifiers with input signal quantization (AISQ) as an alternative to the most common broadband hybrid modulators combining linear and switching (with PWM) amplification channels is considered. It is shown that in order to obtain AISQ high energy characteristics, it is advisable to perform, according to the scheme with output channels parallel connection, the switching of the amplifying cells along the input circuits and to reduce the saturation voltage on the output transistors. An approach has been developed for the AISQ characteristics optimizing according to the criterion of minimum losses. The example of AISQ parameters optimization and its energy characteristics calculation for a linearly increasing signal showed that, compared with a class B amplifier (n = 1), already with three-level quantization, the loss power in the AISQ decreases by 2...2.5 times (depending on the residual transistor voltage). A further increase in n leads to a less sharp decrease in the relative loss power, which, with the obvious complication of the circuitry implementation of such AISQ, makes the use of three-four-level quantization the most expedient. With these parameters, the AISQ becomes competitive with hybrid modulators and does not create electromagnetic interference from the PWM path.

ИМИТАЦИОННАЯ МОДЕЛЬ ДЛЯ ИССЛЕДОВАНИЯ РАБОТЫ КЛЮЧЕВЫХ ВЧ УСИЛИТЕЛЕЙ МОЩНОСТИ С РАЗДЕЛЬНЫМ УСИЛЕНИЕМ СОСТАВЛЯЮЩИХ НА УЗКОПОЛОСНУЮ НАГРУЗКУ

Introduction: High-efficiency switching mode envelope elimination and restoration (EER) RF power amplifiers (PA) are the most promising of a number of "synthetic" power amplification methods for a wide variety of applications. However, when they operate on a mismatched narrow-band load, for example, an electrically short antenna, additional out-of-band emission occurs, which limits the EER PA scope. The purpose of the work is to develop a simulation model for studying the EER switching mode RF PA operation for a narrow-band load. The choice of transient analysis method and use of the freely distributed simulation environment Micro-Cup 12 are substantiated. A number of original solutions are proposed to reduce the computation time. The description of developed model is given, which makes it possible to study the features of the EER PA operation on a narrow-band antenna on a real signal with amplitude& phase modulation fragment. As an example, a DRM digital radio OFDM signal with 10 kHz bandwidth is used. Studies conducted using this model can be proportionally scaled for any frequency band and will allow further development of technical requirements for the EER PA blocks characteristics. Some calculations results showing the developed model adequacy are presented. Practical significance: the use of this model for the subsequent search for solutions to ensure the possibility of EER PA operation for a narrower band load will expand the scope of these high-efficiency power amplifiers.

Комбинирование синтетических методов высокоэффективного высокочастотного усиления

To amplify modern high crest factor telecommunication radio signals with high efficiency, switching operation modes of transistors and synthetic amplification methods are used. The most common of these are the Kahn method (EER – envelope elimination and restoration) and the outphasing method. However, application of these methods has a number of technological (in terms of element base capabilities) limitations on the bandwidth and dynamic range of amplified signal. To expand high-efficiency RF power amplifiers field of application, the possibilities of combination several different synthetic amplification techniques are being considered. Expressions are obtained for the theoretically achievable efficiency when combining the outphasing method with a bridge power combiner and pulse-step modulation of supply voltage. The dependence of average efficiency on the number of supply voltage levels is determined. RF amplified signal bandwidth and its dynamic range determine the minimum required pulse width of the PWM modulator for the EER amplifier. Variants of these characteristics dependence on the number of supply voltage levels are discussed with combined use of PWM and pulse-step modulation of the supply voltage. Directions for further research are formulated.

A multi-band high-efficiency envelope elimination and restoration CMOS power amplifier

A multi-band CMOS power amplifier has been realized to be used in high-efficiency handset applications. The proposed PA is based on class-E stage linearized using envelope elimination and restoration (EER) technique. In order to cover multiple frequency bands, a wide-band passive output matching network is designed and combined with band-select feature. This allows switching between two wide-band output matching networks; increasing frequency coverage and yet satisfying the criteria of high rejection of out-of-band emissions. A design methodology is introduced to optimize the values required for the wide-band passive network. The design has been implemented using CMOS 0.13 μm technology. Simulation results show frequency coverage from 800 MHz to 2.2 GHz with peak efficiency more than 60% (before taking the effect of supply modulator) and 47% after taking the losses of the supply modulator into account. The designed EER system achieves excellent linearity performance. The test and validation process includes LTE test signal with 16 QAM modulation scheme and signal bandwidth of 20 MHz.

System Linearity-Based Characterization of High-Frequency Multilevel DC–DC Converters forS-Band EER Transmitters

In modern telecommunications systems, the requirements for the amount and speed of transmitted data are increasing rapidly. For better spectral efficiency, complex-type modulations [quadrature amplitude modulation (QAM) and orthogonal frequency-division multiplexing (OFDM)] are used, resulting in high peak-to-average power ratio (PAPR) signals. As a consequence, when conventional linear amplifiers (classes A and AB) are used in transmitters, both prominent linearity and poor efficiency are assured. The efficiency of the transmitters can be significantly improved using some of the popular techniques: Kahn envelope elimination and restoration (EER) principle, envelope tracking (ET) technique, Doherty amplifier, and Chireix’s amplifier. In this article, two different approaches in supplying a 2.4-GHz class-E power amplifier (PA) ( ${S}$ -band) based on the EER technique are analyzed and compared. The consistent part of the EER transmitters is a switched-capacitor-based voltage divider combined with a switching structure—analog multiplexer, in the envelope amplifiers (EAs) and a class-E PA. The analog multiplexer is assisted with a series linear regulator in the first system and a fourth-order ${LC}$ filter in the second system, providing supply modulation for the PA. The systems are compared in terms of efficiency and system linearity using the standard metrics [error vector magnitude (EVM) and adjacent channel power ratio (ACPR)]. Special consideration is devoted to the characterization of how the EAs affect the quality of the RF output signal. It is shown that the tested EER transmitters can reproduce 16-QAM and 64-QAM signals up to 2.5 MHz, manifesting an average efficiency of about 32% with the first transmitter, and 16-QAM signals up to 660 kHz RF bandwidth and average efficiency of 44% with the second transmitter. A software tool that accurately estimates the EA linearity is utilized and successfully tested on both EER transmitters.

Efficient Supply Modulator for Wide-Band Envelope Elimination and Restoration Power Amplifiers

A fast transient response supply modulator has been realized and verified in envelope elimination and restoration (EER) power amplifier. The analysis and detailed design of the proposed architecture is presented. Simulation results, in 130-nm CMOS technology, show that the proposed supply modulator achieves better linearity and efficiency compared to the conventional hybrid mode supply modulators or hybrid EER when signal frequency increases. Adjacent channel leakage ratio requirements are met for an LTE signal with 5 MHz, 10 MHz, and 20 MHz BW with error vector magnitude less than 3% and efficiency of 79%, 73%, and 67%, respectively at an output power of 0.45 W. Post-layout simulations are performed across different process corners and the effects of real off-chip components and routes are taken into consideration to verify the robustness of the proposed solution.

A Review of Envelope Tracking Power Supply for Mobile Communication Systems

In modern mobile communication systems, spectral efficient modulation formats have been widely used, which results in the envelope of the radio frequency (RF) signal is variable and having large peak to average power ratio (PAPR). In order to amplify the RF signal without distortion, the linear power amplifier (LPA) is adopted, which is less efficient when powered by constant voltage. Three popular techniques, i.e., Doherty, envelope elimination and restoration (EER), and envelope tracking (ET) techniques, to greatly improve the efficiency of the power amplifiers are analyzed and compared in this paper, and it is shown that the ET technique is the most suitable for future mobile communication systems. In the ET systems, the ET power supply is the key equipment, which dominates the system efficiency. With the development of the mobile communication systems, the bandwidth and the PAPR of the envelope signals are increasing rapidly, which pose severe challenges on the design of the ET power supply. This paper summarizes and sorts the ET power supplies in the literatures, and a detailed comparison is presented to guide the selection of ET power supplies for different applications. Finally, the methods, including soft-switching, slow envelope, and band separation are proposed for further increasing the efficiency of the ET power supply.

A Switched-Capacitor-Controlled Digital-Current Modulated Class-E Transmitter

An envelope elimination and restoration transmitter that comprises a class-E power amplifier (PA) and a digitally controlled current digital-to-analog converter (DAC) modulator are presented. A switched-capacitor DAC is designed to control an open-loop transconductor that operates as a current modulator, modulating the amplitude of the current supplied to a class-E PA. Such a topology allows for increased filtering of the quantization noise that is problematic in most digital PAs (DPA). The system measurements yield a peak output power and system efficiency (SE) of 22.5 dBm and 23.6%, respectively. When applying a local thermal equilibrium signal, the measured error vector magnitude is 3.72% and the adjacent channel leakage ratio is −30.2 dBc, while outputting 18.1 dBm at 10.6% SE.

Optimized Design of GaN Switched-Capacitor-Converter-Based Envelope Tracker for Satellite Application

Envelope tracking and envelope elimination and restoration (EER) are two important techniques used to improve efficiency of power amplifiers. They employ a power supply called envelope tracker to provide a dynamic voltage that tracks the envelope of the transmitted signal. This paper presents an implementation of the envelope tracker based on a multilevel converter in series with a linear regulator for satellite application. In order to have highly efficient and light solution, a switched-capacitor-converter-based multilevel converter is proposed. For the multilevel converter, duty cycle, switching frequency, capacitors, and inductors are optimized based upon the precise power loss model. Two prototypes (GaN-based and Si-based) are fabricated, aiming for a 5-MHz radio frequency envelope signal tracking with a maximum output power of 40 W. The experimental results verify the effectiveness of the proposed configuration with 96.2% efficiency of the multilevel converter and 75% of the envelope tracker. Besides, comparison experiments are performed between the Si-based and GaN-based transistors, which show that the GaN transistors offer better efficiency and, therefore, are preferred for satellite application.

Hybrid Envelope Elimination and Restoration Technique for Enhancing the Linearity of Switchmode Envelope Amplifiers

This letter shows a new technique for enhancing the linearity of switchmode envelope amplifiers used in Envelope Elimination and Restoration (EER) amplifiers. The proposed solution increases the linearity of EER amplifiers using switchmode converters as envelope amplifiers avoiding additional hardware for compensating their inherent distortion at low output voltage levels. This technique combines hybrid EER (H-EER) and drive modulation techniques applied to a radio frequency (RF) amplifier operating in mixed mode. It is illustrated by means of an L-Band suboptimum Class-E power amplifier using GaN HEMTs linearized by a multi-phase switchmode envelope amplifier.

High efficiency radiofrequency power amplifier module for parallel transmit arrays at 3 Tesla.

The purpose of this study is to develop an in-bore radiofrequency (RF) power amplifier (RFPA) module with high power efficiency and density for use in parallel transmit (pTX) arrays at 3 Tesla. The modules use a combination of current mode class D, class S, and class E amplifiers based on enhancement-mode gallium nitride-on-silicon field-effect transistors. Together the amplifiers implement envelope elimination and restoration to achieve amplitude modulation with high efficiency over a wide operating range. The static nonlinearity and power efficiency of the module were measured using pulsed RF measurements over a 37 dB dynamic range. Thermal performance was also measured with and without forced convection cooling. The modules produces peak RF power up to 130 W with an overall efficiency of 85%. When producing 100 W RF pulses at a duty cycle of 10%, maximum junction temperatures did not exceed 80 °C, even without the use of heatsinks or forced convection. The small size and low cost of the modules promise lower cost implementation of pTX systems compared with linear RFPAs located remotely. Further work must be done on control of the RF output in the presence of nonlinearities and coupling. Magn Reson Med 78:1589-1598, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

The Design of a Multilevel Envelope Tracking Amplifier Based on a Multiphase Buck Converter

Envelope tracking (ET) and envelope elimination and restoration (EER) are techniques that have gained in importance in the last decade in order to obtain highly efficient radio frequency power amplifier that transmits signals with high peak-to-average power ratio. In this study, a multilevel multiphase buck converter is presented as a solution for the envelope amplifier used in ET and EER. The presented multiphase buck converter generates multilevel voltage using “node” duty cycles and nonlinear control. In this way, the multilevel is implemented using only one simple power stage. However, the complexity of the multilevel converter implementation has been shifted from complicated power topologies to complicated digital control. Detailed discussion regarding the influence of the design parameters (switching frequency, output filter, and time resolution of the digital control) on the performance of the proposed envelope amplifier is presented. The design of the output filter is conducted fulfilling the constraints of the envelope slew rate and minimum driver pulse that can be reproduced. In the cases when these two constraints cannot be fulfilled, they may be relieved by the modified control that is presented and experimentally validated. Finally, in order to validate the concept, a prototype has been designed and integrated with a nonlinear class F amplifier. Efficiency measurements showed that by employing EER, it is possible to save up to 15% of power losses, comparing to the case when it is supplied by a constant voltage. Additionally, adjacent channel power ratio has been measured. The obtained results showed the value higher than 30 dB for signals up to 5 MHz of bandwidth, without using a predistortion technique.

Linear Regulator Design Considerations of the Serial Linear-Assisted Switching Converter Used as Envelope Amplifier

Envelope elimination and restoration technique and envelope tracking technique are proposed to enhance efficiency of radio frequency power amplifier (RFPA), and both of them take envelope amplifier (EA) as a high slew-rate variable voltage source. Serial linear-assisted switching converter, one of the solutions of EA, has benefits in high tracking bandwidth, high tracking accuracy, and relatively low switching losses. Among those many types of linear-assisted switching converter, the design of a linear regulator is rarely mentioned. This paper proposes a new design of linear regulator to supply a higher voltage and maintain high tracking bandwidth by dividing a linear regulator into four different parts. Beyond that, an input filter is recommended to increase the power supply rejection ratio (PSRR) of a linear regulator in high frequency, which is able to reduce the glitch caused by multilevel voltage power supply. An EA prototype is composed of the proposed linear regulator, the PSRR improvement filter, and the multilevel voltage power supply. To align signals, circular convolution is suggested as a modified algorithm. Experiments show that this prototype has a maximum output of 40 V, a tracking bandwidth of about 2 MHz for a full-range sinusoidal signal, and a tracking ability for OFDM envelope signal with a subcarrier up to 5 MHz.