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An Integrated Linearization Technique for GaAs Bipolar WCDMA Power Amplifier


Affiliations
1 Collaborative Microelectronic Design Excellence Centre, School of Electrical and Electronic Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang, Malaysia
2 Department of Electrical Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
 

Here we report a novel linearization and efficiency improvement technique for heterojunction bipolar transistor (HBT)-based Wireless Code Division Multiple Access (WCDMA) power amplifier. A process solution is proposed where a tantalum nitride (TaN) layer is strapped to the HBT base metal layer that resolves the current hogging issue. This is known as the strap ballasting technique. The resistance introduced by TaN improves the linear output power without trading-off its power added efficiency. At supply voltage of 4 V, the strap ballasting methodology improves the adjacent channel leakage ratio by 4.5 dB compared to the conventional base ballasting technique at output power of 28 dBm. The corresponding improvement in power added efficiency is 4%. The maximum output power delivered by power amplifier is 36 dBm. The proposed technique can be employed in the WCDMA power amplifier to minimize the fundamental trade-off issue between linear output power and efficiency.

Keywords

Heterojunction Bipolar Transistor, Linearization, Power Amplifier, Strap Ballasting Technique.
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  • Ramiah, H., Eswaran, U. and Kanesan, J., A high gain and high linearity class-AB power amplifier for WCDMA applications. Microelectron. Int., 2013, 31(1), 1–7.

  • Qin Ge, Liu, X., Chen, X., Luo, W. and Liu, G., Ku-band high power internally matched GaN HEMTS with 1.5 GHz bandwidth. Microelectron. Int., 2013, 90, 19–23.

  • Drakaki, M., Siskos, S. and Hatzopoulos, A., A 0.5–20 GHz bandwidth enhanced distributed amplifier. Microelectron. Eng., 2012, 90, 26–28.

  • Liu, W., Nelson, S., Hill, D. G. and Khatibzadeh, A., Current gain collapse in microwave multi-finger heterojunction bipolar transistors operated at very high power densities. IEEE Trans. Electron Devices, 1993, 40, 1917–1927.

  • Sweet, A., Designing Bipolar Transistor Radio Frequency Integrated Circuits, Artech House, London, 2008.

  • Jagadheswaran, U. R., Ramiah, H., Mak, P. I. and Martins, R. P., A 2-μm InGaP/GaAs class-J power amplifier for multi-band LTE achieving 35.8-dB gain, 40.5% to 55.8% PAE and 28-dBm linear output power. IEEE Trans. Microwave Theory Technol., 2016, 64, 200–209.

  • Liou, J. J., Liou, L. L. and Huang, C. I., Analytical model for the AlGaAs/GaAs multi-emitter finger HBT including self-heating and thermal coupling effects. IET J. Circuits, Devices Syst., 1994, 141, 469–475.

  • Thein, T. T., Law C. L. and Fu, K., Frequency domain dynamic thermal analysis in GaAs HBT for power amplifier applications. Prog. Electromagn. Res., 2011, 118, 71–87.

  • Liou, L. L., Jenkins, T. and Huang, C. I., Effect of base potential distribution on thermal runaway and the power limitation of the heterojunction bipolar transistor with circular dot geometry. In IEEE, Electron Devices Meeting, Hong Kong, 1996, pp. 49–52.

  • Liu, W. et al., The use of base ballasting to prevent the collapse of current gain in AlGaAs/GaAs heterojunction bipolar transistors. IEEE Trans. Electron. Devices, 1996, 43, 245–251.

  • Bayraktaroglu, B. and Salib, M., Unconditionally thermally stable cascade GaAs HBTs for microwave applications. IEEE Microwave Guided Wave Lett., 1997, 7, 187–189.

  • Jang, J., Kan, E. C., Arnborg, T. Johansson, T. and Dutton, R. W., Characterization of RF power BJT and improvement of thermal stability with nonlinear base ballasting. IEEE J. Solid-State Circuits, 1998, 33, 1428–1432.

  • Jin Dong, Y. et al., A simple method to optimize the ballasting resistor of RF power HBT. In Proceedings of the 7th International Symposium on Antenna Propagation and EM Theory, Guilin, China, 2006, pp. 1–4.

  • Maas, S., Ballasting HBTs for wireless power amplifier operation. In Proceedings of the IEEE International Workshop on Integrated Nonlinear Microwave and Millimeter-Wave Circuits, Portugal, 30 January 2006, pp. 2–5.

  • Eswaran, U., Ramiah, H. and Kanesan, J., Class-E power amplifier with novel pre-distortion linearization technique for 4G mobile wireless communications. Elektron. IR Elektrotech., 2014, 20, 53–56.

  • Matsubara, H., Ishihara, K., Miyadai, N. and Nojima, T., A novel 3rd and 5th order predistortion circuit for 2 GHz band WCDMA amplifier. In Proceedings of Asia-Pacific Conference, APMC 2007, Bangkok, Thailand, 2008, pp. 1–4.

  • Landin, P. N., Fritzin, J., Moer, W. V., Isaksson, M. and Alvanpour, A., Modeling and digital predistortion of class D outphasing RF power amplifiers. IEEE Trans. Microwave Theory Tech., 2012, 60, 1907–1915.

  • Hammi, O., Kwan, A., Bensmida, S. and Morris, K. A., A digital predistortion system with extended correction bandwidth with application to LTE-A nonlinear power amplifiers. IEEE Trans. Circuits Syst., 2014, 61, 3487–3495.

  • Young, S. J., Jukyung, C. and Sangwook, N., High-efficiency power amplifier using novel dynamic bias switching. IEEE Trans. Microwave Theory Techn., 2007, 55, 690–696.

  • Xiaohong, S., Huai, G. and Weifeng, S., Peripheral adaption power cell network for high efficiency and high linearity power amplifier. IEEE Microwave Wireless Components Lett., 2014, 24, 799–801.


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  • An Integrated Linearization Technique for GaAs Bipolar WCDMA Power Amplifier

Abstract Views: 272  |  PDF Views: 84

Authors

Jagadheswaran Rajendran
Collaborative Microelectronic Design Excellence Centre, School of Electrical and Electronic Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang, Malaysia
Sofiyah Sal Hamid
Collaborative Microelectronic Design Excellence Centre, School of Electrical and Electronic Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang, Malaysia
Shukri Korakkottil Kunhi Mohd
Collaborative Microelectronic Design Excellence Centre, School of Electrical and Electronic Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang, Malaysia
Mohd Zaid Abdullah
Collaborative Microelectronic Design Excellence Centre, School of Electrical and Electronic Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang, Malaysia
Harikrishnan Ramiah
Department of Electrical Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
Narendra Kumar
Department of Electrical Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia

Abstract


Here we report a novel linearization and efficiency improvement technique for heterojunction bipolar transistor (HBT)-based Wireless Code Division Multiple Access (WCDMA) power amplifier. A process solution is proposed where a tantalum nitride (TaN) layer is strapped to the HBT base metal layer that resolves the current hogging issue. This is known as the strap ballasting technique. The resistance introduced by TaN improves the linear output power without trading-off its power added efficiency. At supply voltage of 4 V, the strap ballasting methodology improves the adjacent channel leakage ratio by 4.5 dB compared to the conventional base ballasting technique at output power of 28 dBm. The corresponding improvement in power added efficiency is 4%. The maximum output power delivered by power amplifier is 36 dBm. The proposed technique can be employed in the WCDMA power amplifier to minimize the fundamental trade-off issue between linear output power and efficiency.

Keywords


Heterojunction Bipolar Transistor, Linearization, Power Amplifier, Strap Ballasting Technique.

References





DOI: https://doi.org/10.18520/cs%2Fv114%2Fi02%2F308-313