Pub Date : 2013-04-14DOI: 10.1109/IEEE-IWS.2013.6616839
L. D. de Vreede, R. Gajadharsing, W. Neo
The theoretical bandwidth constrains of conventional symmetric and asymmetric Doherty amplifiers are evaluated and compared to those of the recently introduced novel three and 4-way Doherty amplifier configurations. Performance trends are identified and backed-up by practical results.
{"title":"On the bandwidth performance of Doherty amplifiers","authors":"L. D. de Vreede, R. Gajadharsing, W. Neo","doi":"10.1109/IEEE-IWS.2013.6616839","DOIUrl":"https://doi.org/10.1109/IEEE-IWS.2013.6616839","url":null,"abstract":"The theoretical bandwidth constrains of conventional symmetric and asymmetric Doherty amplifiers are evaluated and compared to those of the recently introduced novel three and 4-way Doherty amplifier configurations. Performance trends are identified and backed-up by practical results.","PeriodicalId":344851,"journal":{"name":"2013 IEEE International Wireless Symposium (IWS)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114995688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-04-14DOI: 10.1109/IEEE-IWS.2013.6616709
M. Chaudhary, J. Lees, J. Benedikt, P. Tasker
This paper presents an enhanced active baseband load-pull capability that allows constant, frequency independent baseband load environments to be presented across wide modulation bandwidths. This capability is critical in allowing the effects of baseband impedance variation has on the performance of nonlinear microwave devices, when are driven by broadband multi-tone stimuli, to be fully investigated. The experimental investigations were carried out using a 10W GaN HEMT device, under 9-carrier complex multi-tone excitation.
本文提出了一种增强的有源基带负载-拉能力，允许在宽调制带宽上呈现恒定的、频率无关的基带负载环境。这种能力对于充分研究由宽带多音刺激驱动的非线性微波器件的基带阻抗变化对其性能的影响至关重要。实验研究采用10W GaN HEMT器件，在9载流子复多音激励下进行。
{"title":"Reduction of baseband electrical memory effects using broadband active baseband load-pull","authors":"M. Chaudhary, J. Lees, J. Benedikt, P. Tasker","doi":"10.1109/IEEE-IWS.2013.6616709","DOIUrl":"https://doi.org/10.1109/IEEE-IWS.2013.6616709","url":null,"abstract":"This paper presents an enhanced active baseband load-pull capability that allows constant, frequency independent baseband load environments to be presented across wide modulation bandwidths. This capability is critical in allowing the effects of baseband impedance variation has on the performance of nonlinear microwave devices, when are driven by broadband multi-tone stimuli, to be fully investigated. The experimental investigations were carried out using a 10W GaN HEMT device, under 9-carrier complex multi-tone excitation.","PeriodicalId":344851,"journal":{"name":"2013 IEEE International Wireless Symposium (IWS)","volume":"314 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115446674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-04-14DOI: 10.1109/IEEE-IWS.2013.6616738
L. Jianhua, Zhou Yonggang, Zhu Jun
A novel design of dual-polarized broadband 6~18GHz horn antenna with low SWR (<;2), high gain (13dB~19.5dB) and high isolation (>25dB) is presented. Moreover, the designed antenna exhibits excellent far-field radiation characteristics in the entire operation bandwidth without beam splitting. Applying commercial software Ansoft HFSS, sensitivity analysis is taken with respect to the best antenna performance and manufacturing tolerance. Based on the results, we finally fabricated a sample, the measured results showed good performance.
{"title":"Research and design of broadband horn antenna","authors":"L. Jianhua, Zhou Yonggang, Zhu Jun","doi":"10.1109/IEEE-IWS.2013.6616738","DOIUrl":"https://doi.org/10.1109/IEEE-IWS.2013.6616738","url":null,"abstract":"A novel design of dual-polarized broadband 6~18GHz horn antenna with low SWR (<;2), high gain (13dB~19.5dB) and high isolation (>25dB) is presented. Moreover, the designed antenna exhibits excellent far-field radiation characteristics in the entire operation bandwidth without beam splitting. Applying commercial software Ansoft HFSS, sensitivity analysis is taken with respect to the best antenna performance and manufacturing tolerance. Based on the results, we finally fabricated a sample, the measured results showed good performance.","PeriodicalId":344851,"journal":{"name":"2013 IEEE International Wireless Symposium (IWS)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122992001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-04-14DOI: 10.1109/IEEE-IWS.2013.6616852
T. Gillenwater, M. Schindler
The mobile handset is well established as a business and consumer device, expanding beyond the foundation built on earlier mobile handset technology. The functions and capabilities of the handset are continually evolving. Handset providers, application developers and users are putting ever greater demands on handsets which simultaneously strain limited battery power and require higher data transfer. This results in ever more challenging requirements on the RF front-end of the handset. At the same time there are cost pressures that require functions to be provided ever more economically. This paper discussed these trends, the implications in front-end architecture, and some of the advanced implementations that address these dynamics.
{"title":"Technology trends in mobile handsets","authors":"T. Gillenwater, M. Schindler","doi":"10.1109/IEEE-IWS.2013.6616852","DOIUrl":"https://doi.org/10.1109/IEEE-IWS.2013.6616852","url":null,"abstract":"The mobile handset is well established as a business and consumer device, expanding beyond the foundation built on earlier mobile handset technology. The functions and capabilities of the handset are continually evolving. Handset providers, application developers and users are putting ever greater demands on handsets which simultaneously strain limited battery power and require higher data transfer. This results in ever more challenging requirements on the RF front-end of the handset. At the same time there are cost pressures that require functions to be provided ever more economically. This paper discussed these trends, the implications in front-end architecture, and some of the advanced implementations that address these dynamics.","PeriodicalId":344851,"journal":{"name":"2013 IEEE International Wireless Symposium (IWS)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123694811","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-04-14DOI: 10.1109/IEEE-IWS.2013.6616813
O. Hammi, M. Sharawi, F. Ghannouchi
In this paper, a generalized twin-nonlinear two-box predistorter is proposed for the linearization of highly nonlinear Doherty power amplifiers exhibiting strong memory effects. The proposed predistorter is made of the cascade of a memoryless look-up table followed by a generalized memory polynomial function and thus can be seen as a two-box implementation of the generalized memory polynomial model. The generalized twin-nonlinear two-box predistorter is experimentally benchmarked against the generalized memory polynomial model. The linearization performances of both models when applied on a GaN based Doherty power amplifier driven by a 20MHz LTE signal, demonstrate the superiority of the proposed predistorter which achieves better linearity performance while requiring a lower number of coefficients. Indeed, an extra 5dB is obtained in the ACLR while the number of predistorter coefficients is reduced by more than 60%.
{"title":"Generalized twin-nonlinear two-box digital predistorter for GaN based LTE Doherty power amplifiers with strong memory effects","authors":"O. Hammi, M. Sharawi, F. Ghannouchi","doi":"10.1109/IEEE-IWS.2013.6616813","DOIUrl":"https://doi.org/10.1109/IEEE-IWS.2013.6616813","url":null,"abstract":"In this paper, a generalized twin-nonlinear two-box predistorter is proposed for the linearization of highly nonlinear Doherty power amplifiers exhibiting strong memory effects. The proposed predistorter is made of the cascade of a memoryless look-up table followed by a generalized memory polynomial function and thus can be seen as a two-box implementation of the generalized memory polynomial model. The generalized twin-nonlinear two-box predistorter is experimentally benchmarked against the generalized memory polynomial model. The linearization performances of both models when applied on a GaN based Doherty power amplifier driven by a 20MHz LTE signal, demonstrate the superiority of the proposed predistorter which achieves better linearity performance while requiring a lower number of coefficients. Indeed, an extra 5dB is obtained in the ACLR while the number of predistorter coefficients is reduced by more than 60%.","PeriodicalId":344851,"journal":{"name":"2013 IEEE International Wireless Symposium (IWS)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115693710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-04-14DOI: 10.1109/IEEE-IWS.2013.6616723
Yalong Li, Xiaochun Li, Junfa Mao
In this paper, a novel solution based on weighted Laguerre polynomials finite-difference time-domain (WLP-FDTD) method is proposed for time domain analysis of interconnect modeled as a transmission line. Compared with finite-difference time-domain (FDTD) method, which is an explicit scheme and limited by Courant condition, the WLP-FDTD method is unconditionally stable since the solution is implicit. Numerical results show that the proposed WLP-FDTD solution is as accurate as but much faster than conventional FDTD-based solutions.
{"title":"Time domain analysis of transmission line based on WLP-FDTD","authors":"Yalong Li, Xiaochun Li, Junfa Mao","doi":"10.1109/IEEE-IWS.2013.6616723","DOIUrl":"https://doi.org/10.1109/IEEE-IWS.2013.6616723","url":null,"abstract":"In this paper, a novel solution based on weighted Laguerre polynomials finite-difference time-domain (WLP-FDTD) method is proposed for time domain analysis of interconnect modeled as a transmission line. Compared with finite-difference time-domain (FDTD) method, which is an explicit scheme and limited by Courant condition, the WLP-FDTD method is unconditionally stable since the solution is implicit. Numerical results show that the proposed WLP-FDTD solution is as accurate as but much faster than conventional FDTD-based solutions.","PeriodicalId":344851,"journal":{"name":"2013 IEEE International Wireless Symposium (IWS)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129567731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-04-14DOI: 10.1109/IEEE-IWS.2013.6616794
W. Ding, Gaofeng Wang, X. Chen
Full wave electromagnetic (EM) simulations frequently encounter low-frequency breakdown: for decoupling of electric and magnetic fields in low frequency, the impedance matrix degenerates into near singular matrix and causes convergence problems. The iterative algorithms are currently the primary solvers of matrix equation for massive EM simulation. For absence of constraint between simulation accuracy and the convergence condition for iterative solver, excessively rigorous convergence condition has to be applied to ensure simulation accuracy, as a result, this way leads to over convergence, i.e., converge at unnecessarily high accuracy and simulation time doubly increases. By theoretically analyzing the impedance matrix, connection between simulation accuracy and the relative residual error which serves as the convergence condition in iterative solvers is established, and an accuracy-controlled convergence criterion is proposed. Numerical experiments are included to demonstrate that this convergence criterion effectively avoids the occurrence of over convergence yet insures simulation accuracy; therefore the simulation efficiency is visibly promoted.
{"title":"Accuracy-controlled convergence criterion for full wave simulation","authors":"W. Ding, Gaofeng Wang, X. Chen","doi":"10.1109/IEEE-IWS.2013.6616794","DOIUrl":"https://doi.org/10.1109/IEEE-IWS.2013.6616794","url":null,"abstract":"Full wave electromagnetic (EM) simulations frequently encounter low-frequency breakdown: for decoupling of electric and magnetic fields in low frequency, the impedance matrix degenerates into near singular matrix and causes convergence problems. The iterative algorithms are currently the primary solvers of matrix equation for massive EM simulation. For absence of constraint between simulation accuracy and the convergence condition for iterative solver, excessively rigorous convergence condition has to be applied to ensure simulation accuracy, as a result, this way leads to over convergence, i.e., converge at unnecessarily high accuracy and simulation time doubly increases. By theoretically analyzing the impedance matrix, connection between simulation accuracy and the relative residual error which serves as the convergence condition in iterative solvers is established, and an accuracy-controlled convergence criterion is proposed. Numerical experiments are included to demonstrate that this convergence criterion effectively avoids the occurrence of over convergence yet insures simulation accuracy; therefore the simulation efficiency is visibly promoted.","PeriodicalId":344851,"journal":{"name":"2013 IEEE International Wireless Symposium (IWS)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128951082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-04-14DOI: 10.1109/IEEE-IWS.2013.6616715
S. Qu
Antennas in high speed wireless local-area network (WLAN) at 60 GHz is now becoming a hot topic, and high-gain properties are often preferred due to high transmission loss of the frequencies around 60GHz. In this paper, a 2-element cavity-backed antenna (CBA) array is proposed, which is excited by bowtie dipoles and fed by a transition from a coaxial line to parallel strip lines. The array prototype is fabricated and measured after the parametric optimization is performed. The measured and simulated results agree reasonably with each other, proving that the array can feature an impedance bandwidth of ~8.3% for SWR ≤ 2, a broad gain of 12.6-13.6 dBi, and cross polarization of around -20 dB.
{"title":"Millimeter-wave cavity-backed antenna array with high gain and simple structure","authors":"S. Qu","doi":"10.1109/IEEE-IWS.2013.6616715","DOIUrl":"https://doi.org/10.1109/IEEE-IWS.2013.6616715","url":null,"abstract":"Antennas in high speed wireless local-area network (WLAN) at 60 GHz is now becoming a hot topic, and high-gain properties are often preferred due to high transmission loss of the frequencies around 60GHz. In this paper, a 2-element cavity-backed antenna (CBA) array is proposed, which is excited by bowtie dipoles and fed by a transition from a coaxial line to parallel strip lines. The array prototype is fabricated and measured after the parametric optimization is performed. The measured and simulated results agree reasonably with each other, proving that the array can feature an impedance bandwidth of ~8.3% for SWR ≤ 2, a broad gain of 12.6-13.6 dBi, and cross polarization of around -20 dB.","PeriodicalId":344851,"journal":{"name":"2013 IEEE International Wireless Symposium (IWS)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128970837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-04-14DOI: 10.1109/IEEE-IWS.2013.6616789
V. Camarchia, Jie Fang, G. Ghione, A. Javan Khoshkholgh, J. M. Moreno Rubio, M. Pirola, R. Quaglia, C. Ramella
The paper discusses the bandwidth extension of a second-harmonic tuned GaN Doherty power amplifier: the adopted strategy relies on output wideband compensation stages and input broadband matching. The single-band (3.5 GHz) and the wide-band (3-3.6 GHz) power amplifiers are compared in terms of building blocks design strategy. The performances, experimentally characterized in single- and two-tone conditions, are close to the state-of-the art for these applications, and confirm the validity of the bandwidth extension approach. In fact, output power of more than 43dBm and 6dB back-off efficiency of around 40% are maintained by the bandwidth extension strategy, as well as intermodulation ratio values. Furthermore, digital baseband predistortion is successfully applied to both stages.
{"title":"Bandwidth extension of GaN Doherty power amplifier: Effect on power, efficiency and linearity","authors":"V. Camarchia, Jie Fang, G. Ghione, A. Javan Khoshkholgh, J. M. Moreno Rubio, M. Pirola, R. Quaglia, C. Ramella","doi":"10.1109/IEEE-IWS.2013.6616789","DOIUrl":"https://doi.org/10.1109/IEEE-IWS.2013.6616789","url":null,"abstract":"The paper discusses the bandwidth extension of a second-harmonic tuned GaN Doherty power amplifier: the adopted strategy relies on output wideband compensation stages and input broadband matching. The single-band (3.5 GHz) and the wide-band (3-3.6 GHz) power amplifiers are compared in terms of building blocks design strategy. The performances, experimentally characterized in single- and two-tone conditions, are close to the state-of-the art for these applications, and confirm the validity of the bandwidth extension approach. In fact, output power of more than 43dBm and 6dB back-off efficiency of around 40% are maintained by the bandwidth extension strategy, as well as intermodulation ratio values. Furthermore, digital baseband predistortion is successfully applied to both stages.","PeriodicalId":344851,"journal":{"name":"2013 IEEE International Wireless Symposium (IWS)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125405535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-04-14DOI: 10.1109/IEEE-IWS.2013.6616822
T. Joo, Bonhoon Koo, K. Son, Songcheol Hong
Although a CMOS device has inferior characteristics for PA it allows versatile controls and possible integrations with other circuits. These advantages surely provide us various methods to linearize a PA with resultant high efficiency. Several linearization methods of RF CMOS PAs are introduced in this paper. These are mostly based on adaptively controlling the biases of common source and common gate power transistors with the input envelope in many different manners. The other type effort is shown for a power driver linearizer which is made of a digital vector modulator. As examples, RF CMOS PAs for WCDMA and WLAN are demonstrated.
{"title":"Linearization methods of RF CMOS PAs for mobile communications","authors":"T. Joo, Bonhoon Koo, K. Son, Songcheol Hong","doi":"10.1109/IEEE-IWS.2013.6616822","DOIUrl":"https://doi.org/10.1109/IEEE-IWS.2013.6616822","url":null,"abstract":"Although a CMOS device has inferior characteristics for PA it allows versatile controls and possible integrations with other circuits. These advantages surely provide us various methods to linearize a PA with resultant high efficiency. Several linearization methods of RF CMOS PAs are introduced in this paper. These are mostly based on adaptively controlling the biases of common source and common gate power transistors with the input envelope in many different manners. The other type effort is shown for a power driver linearizer which is made of a digital vector modulator. As examples, RF CMOS PAs for WCDMA and WLAN are demonstrated.","PeriodicalId":344851,"journal":{"name":"2013 IEEE International Wireless Symposium (IWS)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128756018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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