Integrated Filters and Couplers for Next Generation Wireless Tranceivers

Olukoya, O. 2019. Integrated Filters and Couplers for Next Generation Wireless Tranceivers. PhD thesis University of Westminster Computer Science and Enginerring

TitleIntegrated Filters and Couplers for Next Generation Wireless Tranceivers
TypePhD thesis
AuthorsOlukoya, O.
Abstract

The main focus of this thesis is to investigate the critical nonlinear distortion issues affecting RF/Microwave components such as power amplifiers (PA) and develop new and improved solutions that will improve efficiency and linearity of next generation RF/Microwave mobile wireless communication systems. This research involves evaluating the nonlinear distortions in PA for different analog and digital signals which have been a major concern. The second harmonic injection technique is explored and used to effectively suppress nonlinear distortions. This method consists of simultaneously feeding back the second harmonics at the output of the power amplifier (PA) into the input of the PA. Simulated and measured results show improved linearity results. However, for increasing frequency bandwidth, the suppression abilities reduced which is a limitation for 4G LTE and 5G networks that require larger bandwidth (above 5 MHz). This thesis explores creative ways to deal with this major drawback. The injection technique was modified with the aid of a well-designed band-stop filter. The compact narrowband notch filter designed was able to suppress nonlinear distortions very effectively when used before the PA. The notch filter is also integrated in the injection technique for LTE carrier aggregation (CA) with multiple carriers and significant improvement in nonlinear distortion performance was observed. This thesis also considers maximizing efficiency alongside with improved linearity performance. To improve on the efficiency performance of the PA, the balanced PA configuration was investigated. However, another major challenge was that the couplers used in this configuration are very large in size at the desired operating frequency. In this thesis, this problem was solved by designing a compact branch line coupler. The novel coupler was simulated, fabricated and measured with performance comparable to its conventional equivalent and the coupler achieved substantial size reduction over others. The coupler is implemented in the balanced PA configuration giving improved input and output matching abilities. The proposed balanced PA is also implemented in 4G LTE and 5G wireless transmitters. This thesis provides simulation and measured results for all balanced PA cases with substantial efficiency and linearity improvements observed even for higher bandwidths (above 5 MHz). Additionally, the coupler is successfully integrated with rectifiers for improved energy harvesting performance and gave improved RF-dc conversion efficiency

Year2019
FileOludotun_Olukoya_PhD_Thesis.pdf

Related outputs

Impact of 5G Waveforms on Energy Harvesting Rectifier Performance
Olukoya, O., Mlačić, B. and Budimir, D. 2019. Impact of 5G Waveforms on Energy Harvesting Rectifier Performance. IEEE MTT-S Wireless Power Transfer Conference (WPTC), part of Wireless Power Week (WPW2019). London, UK 17 - 21 Jun 2019 IEEE .

Evaluation of Waveform Candidates for 5G Wireless Communications
Olukoya, O. and Budimir, D. 2019. Evaluation of Waveform Candidates for 5G Wireless Communications. European Microwave Conference in Central Europe (EuMCE2019). Prague 13 - 15 May 2019 IEEE .

Miniaturized Quadrature Hybrid Couplers based on Novel U-shaped Transmission Lines
Olukoya, O., Ilic, A.Z., Basu, A. and Budimir, D. 2019. Miniaturized Quadrature Hybrid Couplers based on Novel U-shaped Transmission Lines. Microwave and Optical Technology Letters. 61 (2), pp. 509-512. doi:10.1002/mop.31555

Rectifier Nonlinearity Effects on 4G and 5G Wireless Systems
Olukoya, O. and Budimir, D. 2018. Rectifier Nonlinearity Effects on 4G and 5G Wireless Systems. Budimir, D. (ed.) IEEE MTT-S International Microwave and RF Conference (IMaRC2018). Kolkata, India 28 - 30 Nov 2018 IEEE .

Rectifiers Based on Quadrature Hybrid Coupler with Improved Performance for Energy Harvesting
Unich, G., Olukoya, O. and Budimir, D. 2018. Rectifiers Based on Quadrature Hybrid Coupler with Improved Performance for Energy Harvesting. IEEE Wireless Power Transfer Conference (WPTC2018) . Montreal, Quebec, Canada. 07 Jun - 03 Jul 2018 IEEE . doi:10.1109/WPT.2018.8639267

Highly Efficient Balanced Power Amplifiers for 4G Applications
Olukoya, O., Kodogiannis, V. and Budimir, D. 2018. Highly Efficient Balanced Power Amplifiers for 4G Applications. 41st International Conference on Telecommunications and Signal Processing. Athens 04 - 06 Jul 2018 IEEE . doi:10.1109/TSP.2018.8441354

Highly Efficient Balanced Power Amplifiers for Carrier Aggregation
Olukoya, O. and Budimir, D. 2018. Highly Efficient Balanced Power Amplifiers for Carrier Aggregation. Microwave and Optical Technology Letters. 60 (3), pp. 529-534. doi:10.1002/mop.31014

Miniaturised Inkjet-printed Quadrature Hybrid Couplers for Multiband Wireless Systems
Olukoya, O., Tarczynski, A. and Budimir, D. 2017. Miniaturised Inkjet-printed Quadrature Hybrid Couplers for Multiband Wireless Systems. 2017 IEEE AP-S Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting. San Diego, California, USA 09 - 14 Jul 2017 IEEE . doi:10.1109/USNC-URSI.2017.8074908

Inkjet-Printed Bandstop Filters for Interference Suppression in Multi-Standard Wireless Systems
Olukoya, O. and Budimir, D. 2016. Inkjet-Printed Bandstop Filters for Interference Suppression in Multi-Standard Wireless Systems. IEEE Asia Pacific Microwave Conference (APMC2016). New Delhi, India 05 - 09 Dec 2016 IEEE . doi:10.1109/APMC.2016.7931399

Permalink - https://westminsterresearch.westminster.ac.uk/item/qqwv2/integrated-filters-and-couplers-for-next-generation-wireless-tranceivers


Share this
Tweet
Email