https://galaviz-rf.com/tag/nvna/NVNAWowchemy (https://wowchemy.com)en-usFri, 01 Dec 2017 00:00:00 +0000https://galaviz-rf.com/media/icon_huc0a21cd13d3b330e570311c0697204cf_39767_512x512_fill_lanczos_center_3.pnghttps://galaviz-rf.com/tag/nvna/https://galaviz-rf.com/project/chireix-pa-modeling/Fri, 01 Dec 2017 00:00:00 +0000https://galaviz-rf.com/project/chireix-pa-modeling/<h2 id="overview">Overview</h2> <p>During my time as a <strong>Visiting Scholar</strong> (2014–2016) and Ph.D. research at the <strong>RF Nonlinear Research Laboratory</strong>, Department of Electrical and Computer Engineering, <strong>The Ohio State University</strong>, I conducted extensive measurement campaigns and behavioral modeling of a Chireix outphasing power amplifier system.</p> <h2 id="key-contributions">Key Contributions</h2> <ul> <li>Performed <strong>large-signal dynamic measurements</strong> of a Chireix PA using a nonlinear vector network analyzer (NVNA) to capture AM-AM, AM-PM distortion curves and dynamic efficiency behavior under modulated signal excitation.</li> <li>Developed <strong>NARMA-based behavioral models</strong> to accurately predict the nonlinear memory effects inherent to outphasing PA architectures, where signal recombination introduces load-dependent distortions.</li> <li>Validated models against LTE-Advanced waveforms, demonstrating improved prediction accuracy for efficiency and linearity metrics compared to conventional memoryless polynomial approaches.</li> </ul> <h2 id="tools--technologies">Tools &amp; Technologies</h2> <p>NVNA (Keysight PNA-X), MATLAB, automated RF testbed, signal generators, spectrum analyzers, Keysight ADS.</p> <h2 id="impact">Impact</h2> <p>This work formed the core of my <strong>Ph.D. dissertation</strong>: <em>&ldquo;Measurement and Behavioral Modeling of Dynamic Efficiencies and Linearization of an LTE-A Chireix PA&rdquo;</em> (IPN-CITEDI, 2017), and was supported by an <strong>NSF Scholarship</strong> (2015–2016).</p>