Envelope Following-Based RF Transmitters Using Switching-Mode Power Amplifiers

Jau, Je-Kuan; Chen, Yuan; Horng, Tzyy‐Sheng; Liu, Jianyu

doi:10.1109/lmwc.2006.879471

Cited by 9 publications

(8 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Gaudo [18] and Mury and Fusco [19] provided a Class-E PA analytical method that considers both switch-on resistance and finite dc-feed inductance. In [20]- [24], the authors derived analytical solution that further includes package bondwire inductance. Nevertheless, the experimental results for RF Class-E PAs at gigahertz and sub-gigahertz frequencies often showed that one cannot simply rely on the previously published analytical design equations for the best efficiency design, as was discussed by Lie et al [25].…”

Section: Introductionmentioning

confidence: 99%

“…In the research, the authors found that the high-frequency loss issues would be the main cause because the classic Class-E condition used in these previous Class-E PA designs is true for maximum efficiency based on a lossless switching device model. To overcome the problems, this paper provides a more complete analytical solution based on [20]- [24]. The theory presented differs from the previous ones in [20]- [24] in two aspects, which are: 1) the switch-off resistance effects are included and 2) the classic Class-E condition is modified to find maximum efficiency with considering the In the aspect of linearization, EER and polar modulation techniques provide an effective way to linearize Class-E PAs for application to linear RF transmitters.…”

Section: Introductionmentioning

confidence: 99%

“…To overcome the problems, this paper provides a more complete analytical solution based on [20]- [24]. The theory presented differs from the previous ones in [20]- [24] in two aspects, which are: 1) the switch-off resistance effects are included and 2) the classic Class-E condition is modified to find maximum efficiency with considering the In the aspect of linearization, EER and polar modulation techniques provide an effective way to linearize Class-E PAs for application to linear RF transmitters. However, their drawbacks include requiring wide envelope signal processing bandwidth and degrading efficiency under power backoff.…”

Section: Introductionmentioning

confidence: 99%

“…However, their drawbacks include requiring wide envelope signal processing bandwidth and degrading efficiency under power backoff. In contrast, the hybrid quadrature polar modulation (HQPM) technique proposed by the authors in [20]- [24] can alleviate these drawbacks of EER and polar modulation techniques in the linearization of Class-E PAs. The HQPM technique has its own disadvantage.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Design and Linearization of Class-E Power Amplifier for Nonconstant Envelope Modulation

Chen

Horng

et al. 2009

IEEE Trans. Microwave Theory Techn.

View full text Add to dashboard Cite

This paper presents design and linearization techniques for a highly efficient, but nonlinear Class-E power amplifier (PA) applied to linear RF transmitters. To achieve maximum efficiency for Class-E PA operating above gigahertz frequencies, the proposed design theory modifies the classic Class-E condition and considers switch-on and switch-off resistances in deriving the analytical solution. For linearization, a digital envelope predistorter (DEP) is used to provide predistorted envelope modulation for the RF-input and supply-voltage signals fed to the Class-E PA. This DEP can successfully compensate for AM/AM and AM/PM distortions such that the Class-E PA, although classified as a switching-mode PA, can act as a linear PA. A cdma2000 1 transmitter incorporating this Class-E PA and DEP is demonstrated to simultaneously achieve high efficiency and high modulation quality.Index Terms-cdma2000 1 transmitter, class-E power amplifier (PA), digital predistorter, PA linearization techniques.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Design and Linearization of Class-E Power Amplifier for Nonconstant Envelope Modulation

Chen

Horng

et al. 2009

IEEE Trans. Microwave Theory Techn.

View full text Add to dashboard Cite

show abstract

“…7 Envelope following uses a DC-DC converter to modulate the supply of the PA and introduce the amplitude modulation. 8 While using switching PAs in these approaches may allow the individual amplifiers to have high efficiency, the overall system efficiency is often significantly less than the amplifier. …”

Section: Introductionmentioning

confidence: 99%

A Constant Conduction Angle Biased RF Power Amplifier for Improved Linearization in Class C Operation

LaCaille¹

View full text Add to dashboard Cite

Class C power amplifiers offer higher efficiency than class B power amplifiers, but suffer from poor linearity. A feedback based biasing system to improve the linearity of a class C power amplifier is designed. A class B amplifier with a gain of 20 dB and 20 MHz bandwidth at 900 MHz acts as the launching point for the design. The biasing and output network of the class B power amplifier is modified to produce a class C amplifier at conduction angles of 180°, 162°, 126°, 90°, and 54°. A feedback based biasing system, which uses two matched and scaled down transistors, compares the DC current of a class B and a class C biased transistor. This comparison is used to control the biasing voltage of the amplifier. The performance for each class C amplifier is simulated with the proposed constant conduction angle biasing (CCAB) system. The conduction angle, transducer gain, operational gain, VSWR, and drain efficiency are measured from simulation for each of the 5 normally biased and 5 CCAB amplifiers. Dynamic ranges of over 8 dB are demonstrated for the CCAB amplifiers. The effects of loop gain, temperature, and operating frequency for the 126° amplifier are simulated. The 3 rd order intermodulation products of a 10 MHz AM modulated 900 MHz signal are compared for the 126° normally biased and CCAB biased amplifier as well as the class B amplifier. The difference between the fundamental and the 3 rd order intermodulation products is shown to improve from 9.9 dB for the normal class C to 28.7 dB for the CCAB amplifier.

show abstract

Dynamic biasing in SiGe HBT for wideband step envelope tracking power amplifiers

Cidronali

Magrini

Fagotti

et al. 2008

Int J RF and Microwave Comp Aid Eng

View full text Add to dashboard Cite

This article investigates the use of reconfigurable class-AB power amplifiers in wideband step envelope tracking (SET) architectures. The experimental results are related to a SiGe-HBT power-device prototype in which a dynamic switching capability has been integrated. The SET architecture is complemented by a digital predistortion algorithm and the resulting structure (circuit plus algorithm) is analyzed at system level. As a result, the SiGe prototype is capable to provide 20 dBm total output power with EVM 5 5.1%. In the case of 802.11g and WCDMA signals the proposed approach gives a relative average PAE enhancement in excess of 46% with respect to traditional class-AB RF power amplifiers.

show abstract

Envelope Following-Based RF Transmitters Using Switching-Mode Power Amplifiers

Cited by 9 publications

References 5 publications

Design and Linearization of Class-E Power Amplifier for Nonconstant Envelope Modulation

Design and Linearization of Class-E Power Amplifier for Nonconstant Envelope Modulation

A Constant Conduction Angle Biased RF Power Amplifier for Improved Linearization in Class C Operation

Dynamic biasing in SiGe HBT for wideband step envelope tracking power amplifiers

Contact Info

Product

Resources

About