Characterization of RF Power Amplifier for Narrow and Wide Band Memory Polynomial Implementations

  • Ghulam Mohiuddin Department of Electronic Engineering, QUEST, Nawabsah, Pakistan
  • Muhammad Mujtaba Shaikh Department of Telecommunication Engineering, QUEST, Nawabsah, Pakistan
  • Safia Amir Dahri Department of Telecommunication Engineering, QUEST, Nawabsah, Pakistan
  • Fozia Panhwar Department of Telecommunication Engineering, QUEST, Nawabsah, Pakistan
  • Kamran Ali Memon Department of Telecommunication Engineering, QUEST, Nawabsah, Pakistan
  • Nuzhat Madina Department of Telecommunication Engineering, QUEST, Nawabsah, Pakistan
Keywords: Memory Polynomial, Predistortion, Spectral Regrowth, Power Amplifier

Abstract

Linearly efficient RF power amplifiers have a tremendous role in wireless communication and radar systems as they lie at the front end of most RF systems. In today’s world of wireless communication, it is not an easy task to design a RF power amplifier that is linearly efficient. There are two main key challenges that one face for making RF power amplifier’s behavior linearly efficient. First is to characterize RF power amplifier’s coefficients smartly. Second is to propose an approach that works on input signal and make its behavior inverse to that of the designed amplifier behavior so that overall response of the system becomes linear. For countering first challenge, most advanced universally accepted algorithms like Memory Polynomial, Generalized Hammerstein, Cross-term Memory Polynomial and Cross-term Hammerstein are implemented to design RF power amplifier models. For countering second challenge, latest DPD algorithms are implemented which make net response of a system linear. The memory models for modelling RF power amplifier are categorized for narrowband and wideband applications. The narrowband power amplifier models include Memory Polynomial and Cross-term Memory Polynomial models whereas wideband power amplifier models include Generalized Hammerstein and Cross-term Hammerstein models. In this paper, various performance indicators like Standard Deviation (SD), Third Order Intercept (TOI), Intermodulation Distortion Products (IMD3), Modulation Error Ratio (MER), Spurious Free Dynamic Range (SFDR) and Error Vector Magnitude (EVM) are used to characterize RF power amplifier for both narrow and wide band applications. The simulation results show that under narrowband applications, Cross-term Memory Polynomial model works best as it has least standard deviation and is also satisfying other performance parameters up to appreciable level with and without DPD algorithm implementation. While for wideband applications, Cross-term Hammerstein model satisfies the performance measuring parameters excellently.

Published
2021-06-30
How to Cite
Mohiuddin, G., Shaikh, M., Dahri, S., Panhwar, F., Memon, K., & Madina, N. (2021). Characterization of RF Power Amplifier for Narrow and Wide Band Memory Polynomial Implementations. Quaid-E-Awam University Research Journal of Engineering, Science & Technology, Nawabshah., 19(1), 18-27. https://doi.org/10.52584/QRJ.1901.03