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A new modulator for digital RF power amplifiers utilizing a wavetable approach

  • Florian Hühn (a1), Andreas Wentzel (a1) and Wolfgang Heinrich (a1)
Abstract

This paper presents for the first time a wavetable-based coding scheme to generate a high-speed binary input signal for digital RF power amplifiers. The approach maximizes the utilization of the time domain handling capabilities of the pulse forming circuit. Key features are a greatly improved output spectrum purity in comparison with common digital modulators, the ability to adjust the modulator to any given pulse forming hardware and a built-in signal correction option that comes without additional computational cost. To give a first impression on the modulators behavior and its possibilities to adapt to different hardware constraints, simulations are carried out for different parameter variations and for different baseband bandwidths. Furthermore, the proposed concept is emulated with an arbitrary waveform generator to gather additional measurement data. For a 5 MHz wideband code division multiple access (WCDMA) signal (6.5 dB peak-to-average power ratio) at 900 MHz, an error vector magnitude (EVM) of 0.26% and better than >58 dB adjacent channel leakage ratio (ACLR) were recorded. To the authors’ knowledge, these are the best values achieved so far for a single-bit coding scheme without digital predistortion that still maintains maximum power coding efficiency.

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Corresponding author
Corresponding author: F. Hühn Email: florian.huehn@fbh-berlin.de
References
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[1] HungT.P.; RodeJ.; LarsonL.E.; AsbeckP.M.: H-bridge class-D power amplifiers for digital pulse modulation transmitters, in IEEE MTT-S IMS Dig., 2007, 10911094.
[2] WentzelA.; ChevtchenkoS.; KurpasP.; HeinrichW.: A flexible GaN MMIC enabling digital power amplifiers for the future wireless infrastructure, in IEEE MTT-S IMS Dig., 2015, TH2B-5, 14.
[3] MarkertD.; HaslachC.; HeimpelH.; PaschtA.; FischerG.: Phase-modulated DSM-PWM hybrids with pulse length restriction for switch-mode power amplifiers, in Proc. of the 9th Eur. Microwave Integrated Circuit Conf. (EuMIC), 2014, 420423.
[4] MaierS. et al. : 900 MHz pulse-width-modulated class-S power amplifier with improved linearity, in IEEE MTT-S IMS Dig., 2011, WE2D-1, 14.
[5] WaghP.; MidyaP.; RakersP.: Distortionless RF pulse width modulation, in 45th Midwest Symp. on Circuits and Systems, 2002, pp. 124127.
[6] SchemelR.E.: Neoteric signal: method for linearising narrow-band amplifiers or signal paths up to their peak powers. IEEE Electron. Lett., 36 (7) (2000), 666667.
[7] HoriS.; KunihiroK.; TakahashiK.; FukaishiM.: A 0.7–3 GHz envelope ΔΣ modulator using phase modulated carrier clock for multi-mode/band switching amplifiers, in IEEE RF Integrated Circuits Symp., 2011, 14.
[8] TanioM.; HoriS.; HayakawaM.; TawaN.; MotoiK.; KunihiroK.: A linear and efficient 1-bit digital transmitter with envelope delta-sigma modulation for 700 MHz LTE, in 2014 IEEE MTT-S Int. Microwave Symp. (IMS2014), 2014, 14.
[9] JohnsonT.; ShawnP.; StapletonS.P.: RF class-D amplification with bandpass sigma–delta modulator drive signals. IEEE Trans. Circuits Syst. I: Regul. Pap., 53 (12) (2006), 25072520.
[10] HühnF.; WentzelA.; HeinrichW.: GaN-based digital transmitter chain utilizing push-pull gate drivers for high switching speed and built-in DPD, accepted for publication, in Proc. of the 12th European Microwave Integrated Circuits Conf. (EuMIC), October 2017.
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International Journal of Microwave and Wireless Technologies
  • ISSN: 1759-0787
  • EISSN: 1759-0795
  • URL: /core/journals/international-journal-of-microwave-and-wireless-technologies
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