Skip to main content Accessibility help
×
Home

Interference cancellation for higher harmonics of supply-modulated efficient RF power amplifier systems

  • Mohammad Omer (a1) and Farasat Munir (a2)

Abstract

In building highly efficient transmitters of today, one is forced to sacrifice linearity for efficiency. Some of the highest power amplifier efficiency figures are reported by envelope tracking (ET) amplifiers. These amplifiers can generate strong higher-order harmonics, which can lead to interference with receivers operating at the harmonic frequencies. Using non-linear interference cancellation, we can help to remove the interference being caused in those receivers. This paper looks at the problem of modeling the third and second-order harmonic emission from an ET amplifier. It derives the non-linear kernel for estimating such interference. This kernel has been rigorously expanded to show its correlation with the various harmonics and its effectiveness in predicting the harmonic content. We then set up an envelope amplifier test-bench to capture harmonic signal content and cancel it using the derived kernel model. The experiment yields excellent agreement with theory and provides a validation of the system and concept.

Copyright

Corresponding author

Corresponding author: F. Munir Email: farasat.munir@lums.edu.pk

References

Hide All
[1] Kim, J.; Son, J.; Jee, S.; Kim, S.; Kim, B.: Optimization of envelope tracking power amplifier for base-station applications. IEEE Trans. Microw. Theory Tech., 61 (4) (2013), 16201627.
[2] Zhou, G.T.: Analysis of spectral regrowth of weakly nonlinear power amplifiers, in IEEE Int.l Conf. on Acoustics, Speech, and Signal Processing, Proceedings, vol. 5, 2000, 27372740.
[3] Ku, H.; Kenney, J.S.: Behavioral modeling of RF power amplifiers considering IMD and spectral regrowth asymmetries, in IEEE MTT-S Int. Microwave Symp. Digest, vol. 2, 2003, 799802.
[4] Gard, K.G.; Gutierrez, H.M.; Steer, M.B.: Characterization of spectral regrowth in microwave amplifiers based on the nonlinear transformation of a complex Gaussian process. IEEE Trans. Microw. Theory Tech., 47 (7) (1999), 10591069.
[5] Omer, M.; Rimini, R.; Heidmann, P.; Kenney, J.S.: A compensation scheme to allow full duplex operation in the presence of highly nonlinear microwave components for 4 G systems, in IEEE MTT-S Int. Microwave Symp. Digest (MTT), 2011, 14.
[6] Omer, M.; Rimini, R.; Heidmann, P.; Kenney, J.S.: A PA-noise cancellation technique for next generation highly integrated RF front-ends, in IEEE Radio Frequency Integrated Circuits Symp. (RFIC), Montreal, QC, 2012, 471474.
[7] Zhou, J.; Chakrabarti, A.; Kinget, P.R.; Krishnaswamy, H.: Low-noise active cancellation of transmitter leakage and transmitter noise in broadband wireless receivers for FDD/co-existence. IEEE J. Solid-State Circuits, 49 (12) (2014), 30463062.
[8] Razavi, B.: The future of radios, in IEEE Int. Symp. on Circuits and Systems (ISCAS), 2015, 18.
[9] Fabiano, I.; Sosio, M.; Liscidini, A.; Castello, R.: SAW-less analog front-end receivers for TDD and FDD. IEEE J. Solid-State Circuits, 48 (12) (2013), 30673079.
[10] Goel, A.; Analui, B.; Hashemi, H.: Tunable duplexer with passive feed-forward cancellation to improve the RX-TX isolation. IEEE Trans. Circuits Syst. I: Regul. Pap., 62 (2) (2015), 536544.
[11] Schafer, S.; Popovic, Z.: Multi-frequency measurements for supply modulated transmitters. IEEE Trans. Microw. Theory Tech., 63 (9) (2015), 29312941.
[12] Raffo, A.; Bosi, G.; Vadala, V.; Vannini, G.: Behavioral modeling of GaN FETs: a load-line approach. IEEE Trans. Microw. Theory Tech., 62 (1) (2014), 7382.
[13] Santarelli, A.; Di Giacomo, V.; Raffo, A.; Traverso, P.A.; Vannini, G.; Filicori, F.: A nonquasi-static empirical model of electron devices. IEEE Trans. Microw. Theory Tech., 54 (12) (2006), 40214031.
[14] Omer, M.; Rimini, R.; Draxler, P.J.; Kenney, J.S.: Interference cancellation for odd harmonics of envelope tracking RF power amplifier systems, in IEEE MTT-S Int. Microwave Symp. Digest (IMS), 2013, 13.
[15] Ku, H.; Mckinley, M.D.; Kenney, J.S.: Extraction of accurate behavioral models for power amplifiers with memory effects using two-tone measurements, in IEEE MTT-S Int. Microwave Symp. Digest, vol. 1, 2002, 139142.

Keywords

Interference cancellation for higher harmonics of supply-modulated efficient RF power amplifier systems

  • Mohammad Omer (a1) and Farasat Munir (a2)

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed