Predistortion Compensation of the Intermodulation Products in Microwave Power Amplifiers
Abstract
The article presents an analysis of various technical solutions focused on correction of amplitude and amplitude-phase distortions of modulated signals that occur in vacuum and solid-state microwave power amplifiers as a result of nonlinear changes of instantaneous current values in active amplifying devices. It is shown that intermodulation distortions of odd orders in the vicinity of the input signal main frequency band degrade the amplifier’s power efficiency and give rise to additional side spectrum components, which violate strict requirements for electromagnetic compatibility for radio electronic devices and lead to the necessity to operate the amplifier well below its power rating for reducing the distortion levels. It is noted that there is a tendency toward increasing the information transmission rate in microwave bands along with growing requirements for the mass, dimensions, and reliability of automatic on-board satellite equipment. In view of these circumstances, after the period during which structural digital-and-analog and fully digital solutions were elaborated, some developers turn back to analog solutions that do not require introduction of complicated digital-and-analog components into the microwave signal flow path and open the possibility to widen the information frequency band of transmitted signals. The article presents the results from studying a microstrip linearizer on its simulation model. The linearizer model contains nonlinear elements made using domestically produced high-speed Schottky diodes with decoupling circuits on the basis of two hybrid microstrip bridges. The model of a standard traveling-wave tube (TWT) with an 11 GHz central frequency that takes into account the AM/AM and AM/PM distortions occurring in this TWT is used as the active component. The measurement results have shown that in case of using the optimal combination of linearizer parameters, the modulated signal input power in its main band can be increased by 2 dB in comparison with the TWT without the linearizer, with concurrently decreasing the level of side spectrum distortion by 12 and 21 dB for third- and fifth-order components, respectively. The microstip predistortion diode linearizer development results can be used in constructing a satellite on-board radio transmitting equipment with improved characteristics.
References
2. Tuo W. e. a. Theoretical Analysis and an Improvement Method of the Bias Effect on the Linearity of RF Linear Power Amplifiers // J. Semiconductors. 2009. V. 30. No. 5. Pp. 1—7.
3. Ahmad I. e. a. Spectral Broadening Effects of High Power Amplifiers in MIMO OFDM Relaying Channels // EURASIP J. Wireless Communications and Networking. 2013. V. 32. Pp. 240—245.
4. O’Droma M., Yiming L. A New Bessel-Fourier Memoryless Nonlinear Power Amplifier Behavioral Model // IEEE Microwave and Wireless Components Lett. 2013. V. 23 (1). Рp. 25—27.
5. Liu Y.J. e. a. A Robust Augmented Complexity-Reduced Generalized Memory Polynomial for Wideband RF Power Amplifiers // IEEE Trans. Indus. Elect. 2014. V. 61. Iss. 5. Рp. 2389—2401.
6. Landin P.N. e. a. Two Novel Memory Polynomial Models for Modeling of RF Power Amplifiers // Intern. J. Microwave and Wireless Techn. 2015. V. 7. Рp. 19—29.
7. Аверина Л.И., Бобрешов А.М., Шутов В.Д. Повышение линейности передающего тракта методом цифровых предыскажений // Нелинейный мир. 2013. № 10. С. 720—727.
8. Renzo M. e. a. Spatial Modulation for Generalized MIMO: Challenges, Opportunities and Implementation // Proc. IEEE. 2014. V. 102. No. 1. Рp. 56—103.
9. Uthirajoo E. e. a. Wideband LTE Power Amplifier with Integrated Novel Analog Pre-distorter Linearizer for Mobile Wireless Communications // PLoS ONE. 2014. V. 9. No. 7. Pp. 1—16.
10. Vasconcellos V. e. a. Performance of 5G Candidate Waveforms with Non-linear Power Amplifiers // Proc. IEEE 9 th Latin-american Conf. Communications. 2017. Pp. 1—5.
11. Wang Z. e. a. Deep Neural Nets Based Power Amplifier Non-linear Pre-distortion // J. Physics: Conf. Series. 2017. V. 887. Рp. 1—6.
12. Yousif S.M. e. a. Efficient Low-complexity Digital Predistortion for Power Amplifier Linearization // Intern. J. Electrical and Computer Eng. 2016. V. 6 (3). Pp. 1096—1105.
13. Пат. № 2538306 РФ. Формирователь радиосигналов с цифровым предыскажением четными гармониками / А.С. Кондрашов // Бюл. изобрет. 2015. № 1.
14. Jebali C. e. a. Selective Orthogonal Predistortion for Power Amplifiers // IEEE 28 th Canadian Conf. Electrical and Computer Eng. 2015. Pp. 1600—1604.
15. Essaadali R. e. a. Optimization of Multi-standard Transmitter Architecture Using Single-double Conversion Technique Used for Rescue Operations // Advances in Sci., Techn. and Eng. Syst. J. 2017. V. 2. No. 3. Рp. 73—81.
16. Bhat S., Chockalingam A. Compensation of Power Amplifier Nonlinear Distortion in Spatial Modulation Systems // Proc. of IEEE 17 th Intern.Workshop on Signal Processing Advances in Wireless Communications. 2016. Рp. 1—6.
17. Петушков С.В., Белов Л.А., Кондрашов А.С. Использование четных гармоник для цифрового предыскажения входного сигнала при линеаризации амплитудных характеристик СВЧ-усилителя мощности // T-Comm — Телекоммуникации и транспорт. 2016. Т. 10. № 6. C. 3—7.
18. Swaminathan J.N., Kumar P. Design of Efficient Adaptive Predistorter for Nonlinear High Power Amplifier // Wireless Personal Comm. 2015. V. 82 (2). Рp. 1085—1093.
19. Jie L., Hua-Dong Z. A Novel Two-branch Predistortion Linearizer of Ku-band TWTA in Communication Application // Proc. Intern. Radar Conf. 2015. P. 3.
20. Li D. e. a. Tunable Diode-based Predistortion Linearizer for Power Aplifier with Phase Expansion or Compression at Millimeter-wave Frequency // IEEE Intern. Conf. Communication Problem-solving. 2014. Pp. 1610—1613.
21. Deng H.-L., Zhang D.-W. A Kaband Analog Predistortion Linearizer for Travelling Wave Tube Amplifiers // Proc. Asia-Pacific Microwave Conf. 2015. V. 1. Pp. 1—3.
22. Bo Shi e. a. A novel GHz Bandwidth RF Predistortion Linearizer for Ka-band Power Amplifier // Proc. IEEE Conf. TENCON. 2017. Р. 1610—1613.
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Для цитирования: Петушков С.В., Белов Л.А., Вильдерман Е.Н. Предыскажающая компенсация продуктов интермодуляции в усилителях мощности сверхвысокочастотных сигналов // Вестник МЭИ. 2018. № 5. С. 139—145. DOI: 10.24160/1993-6982-2018-5-139-145.
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1. Kim Y. e. a. An analog Lineariser Based on Amplitude Modulation with Even Harmоnic Signals. Microwave J. 2009;52;2:80—88.
2. Tuo W. e. a. Theoretical Analysis and an Improvement Method of the Bias Effect on the Linearity of RF Linear Power Amplifiers. J. Semiconductors. 2009;30;5. Pp. 1—7.
3. Ahmad I. e. a. Spectral Broadening Effects of High Power Amplifiers in MIMO OFDM Relaying Channels. EURASIP J. Wireless Communications and Networking. 2013;32:240—245.
4. O’Droma M., Yiming L. A New Bessel-Fourier Memoryless Nonlinear Power Amplifier Behavioral Model. IEEE Microwave and Wireless Components Lett. 2013;23 (1):25—27.
5. Liu Y.J. e. a. A Robust Augmented Complexity-Reduced Generalized Memory Polynomial for Wideband RF Power Amplifiers. IEEE Trans. Indus. Elect. 2014;61;5:2389—2401.
6. Landin P.N. e. a. Two Novel Memory Polynomial Models for Modeling of RF Power Amplifiers. Intern. J. Microwave and Wireless Techn. 2015;7:19—29.
7. Averina L.I., Bobreshov A.M., Shutov V.D. Povyshenie Lineĭnosti Peredayushchego Trakta Metodom Tsifrovykh Predyskazhenii. Nelineĭnyĭ mir. 2013;10:720—727. (in Russian).
8. Renzo M. e. a. Spatial Modulation for Generalized MIMO: Challenges, Opportunities and Implementation. Proc. IEEE. 2014;102;1:56—103.
9. Uthirajoo E. e. a. Wideband LTE Power Amplifier with Integrated Novel Analog Pre-distorter Linearizer for Mobile Wireless Communications. PLoS ONE. 2014;9;7:1—16.
10. Vasconcellos V. e. a. Performance of 5G Candidate Waveforms with Non-linear Power Amplifiers. Proc. IEEE 9 th Latin-american Conf. Communications. 2017:1—5.
11. Wang Z. e. a. Deep Neural Nets Based Power Amplifier Non-linear Pre-distortion. J. Physics: Conf. Series. 2017;887:1—6.
12. Yousif S.M. e. a. Efficient Low-complexity Digital Predistortion for Power Amplifier Linearization. Intern. J. Electrical and Computer Eng. 2016;6 (3):1096—1105.
13. Pat. № 2538306 RF. Formirovatel' Radiosignalov s Tsifrovym Predyskazheniem Chetnymi Garmonikami. A.S. Kondrashov. Byul. Izobret. 2015;1. (in Russian).
14. Jebali C. e. a. Selective Orthogonal Predistortion for Power Amplifiers. IEEE 28 th Canadian Conf. Electrical and Computer Eng. 2015:1600—1604.
15. Essaadali R. e. a. Optimization of Multi-standard Transmitter Architecture Using Single-double Conversion Technique Used for Rescue Operations. Advances in Sci., Techn. and Eng. Syst. J. 2017;2;3:73—81.
16. Bhat S., Chockalingam A. Compensation of Power Amplifier Nonlinear Distortion in Spatial Modulation Systems. Proc. of IEEE 17 th Intern.Workshop on Signal Processing Advances in Wireless Communications. 2016:1—6.
17. Petushkov S.V., Belov L.A., Kondrashov A.S. Ispol'zovanie Chetnykh Garmonik dlya Tsifrovogo Predyskazheniya Vkhodnogo Signala pri Linearizatsii Amplitudnykh Kharakteristik SVCH-Usilitelya Moshchnosti. T-Comm — Telekommunikatsii i Transport. 2016;10;6: 3—7. (in Russian).
18. Swaminathan J.N., Kumar P. Design of Efficient Adaptive Predistorter for Nonlinear High Power Amplifier. Wireless Personal Comm. 2015;82 (2):1085—1093.
19. Jie L., Hua-Dong Z. A Novel Two-branch Predistortion Linearizer of Ku-band TWTA in Communication Application. Proc. Intern. Radar Conf. 2015:3.
20. Li D. e. a. Tunable Diode-based Predistortion Linearizer for Power Amplifier with Phase Expansion or Compression at Millimeter-wave Frequency. IEEE Intern. Conf. Communication Problem-solving. 2014:1610—1613.
21. Deng H.-L., Zhang D.-W. A Ka-band Analog Predistortion Linearizer for Travelling Wave Tube Amplifiers. Proc. Asia-Pacific Microwave Conf. 2015;1:1—3.
22. Bo Shi e. a. A novel GHz Bandwidth RF Predistortion Linearizer for Ka-band Power Amplifier. Proc. IEEE Conf. TENCON. 2017:1610—1613.
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For citation: Petushkov S.V., Belov L.A., Vilderman E.N. Predistortion Compensation of the Intermodulation Products in Microwave Power Amplifiers. MPEI Vestnik. 2018;5:139—145. (in Russian). DOI: 10.24160/1993-6982-2018-5-139-145.
