Hai Yu, Varun Ratnasamy, P. Roblin, M. Rawat, C. Xie
{"title":"Automatic feed-forward cancellation of modulated harmonic","authors":"Hai Yu, Varun Ratnasamy, P. Roblin, M. Rawat, C. Xie","doi":"10.1109/ARFTG.2015.7381464","DOIUrl":"https://doi.org/10.1109/ARFTG.2015.7381464","url":null,"abstract":"This paper presents an algorithm for the simultaneous linearization and cancellation of modulated harmonics of broadband power amplifiers (PA). The algorithm relies on a joint system identification of the nonlinearity, memory effects and group delay of both the main and harmonic cancellation channels using a recently reported cubic spline basis. The filter-less cancellation of the modulated harmonics uses both the method of predistortion and feedforward while the synchronized PA linearization relies solely on digital predistortion. Experimental verification with a broadband PA yields a reduction of 31 dB of the third harmonic to 59 dBc below the main channel. Simultaneously the linearization provides -40 dB NMSE and 49.5 and 50 dBc ACPR at the fundamental frequency.","PeriodicalId":170825,"journal":{"name":"2015 86th ARFTG Microwave Measurement Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130901819","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}
{"title":"Evaluation and modeling of measurement resolution of a vector network analyzer for extreme impedance measurements","authors":"F. Mubarak, Raffaele Romano, M. Spirito","doi":"10.1109/ARFTG.2015.7381475","DOIUrl":"https://doi.org/10.1109/ARFTG.2015.7381475","url":null,"abstract":"A broadband S-parameter measurement system for extreme impedance measurements is proposed and analyzed in terms of its accuracy. Measurement speed and system resolution at extreme impedance values is comparable to that of a conventional Vector Network Analyzer performance achieved for 50 Q device measurements. A dedicated one-port calibration method is modeled in a circuit simulator environment and implemented for the proposed system. Compared to the 0.05 % measurement resolution in extreme impedance measurements using a state-of-art 50 Q VNA, an almost fifty times lower 0.001 % resolution is achieved with the proposed VNA system utilizing an interferometric principle, with active compensation of reflected waves.","PeriodicalId":170825,"journal":{"name":"2015 86th ARFTG Microwave Measurement Conference","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126681483","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}