This Transactions' Mini-Special Issue includes four papers from the 2013 Radio Frequency Integrated Circuits (RFIC) Symposium, Seattle, WA, USA, June 2-4, 2013. The symposium is one of the IEEE Microwave Theory and Techniques Society (IEEE MTT-S) premier symposia and is co-located with the IEEE MTT-S International Microwave Symposium (IMS) each year. Out of 202 papers submitted, 103 papers were accepted (51% acceptance rate) for presentation in the conference and publication in the 2013 RFIC Symposium Digest. These papers have also been published online on IEEE Xplore. After the symposium, the conference chairs invited eight authors of papers presented at the symposium to submit expanded papers to this Transactions' Mini-Special Issue. A total of six papers were submitted, and the reviewers for every paper were selected from the RFIC Technical Program Committee and this Transactions' Editorial Board. After rigorous reviews, four papers were accepted for publication in this Mini-Special Issue. Each of the Mini-Special Issue papers is briefly described.