@article{adams_genovesi_yang_antonino-daviu_2022, title={Antenna Element Design Using Characteristic Mode Analysis: Insights and Research Directions.}, volume={2}, ISSN={["1558-4143"]}, DOI={10.1109/MAP.2022.3145718}, abstractNote={This article provides a comprehensive review of recent applications of characteristic mode analysis (CMA) to innovative antenna element designs, including multiport, circularly polarized, wideband, reconfigurable, and dielectric resonator antennas (DRAs). Emphasis is placed on the interpretation of the characteristic modes (CMs) for those unfamiliar with the method and physical insights gained from the characteristic eigenvalues and eigenvectors of an antenna. In addition, we review CMA-based design strategies and specific design examples that highlight the application of CMA to various types of antennas. Ultimately, this article seeks to demonstrate the value of CMA-based design insights for antenna engineering and look toward promising new research directions for CMA and antenna research.}, journal={IEEE ANTENNAS AND PROPAGATION MAGAZINE}, author={Adams, Jacob J. and Genovesi, Simone and Yang, Binbin and Antonino-Daviu, Eva}, year={2022}, month={Feb} }
 @article{yang_kim_adams_2022, title={Fundamental Limits on Substructure Dielectric Resonator Antennas}, volume={3}, ISSN={["2637-6431"]}, DOI={10.1109/OJAP.2021.3133725}, abstractNote={We show theoretically that the characteristic modes of dielectric resonator antennas (DRAs) must be capacitive in the low frequency limit and that as a consequence of this constraint and the Poincaré Separation Theorem, the modes of any DRA consisting of partial elements of an encompassing super-structure with the same spatial material properties cannot resonate at a lower frequency than the encompassing structure. Thus, design techniques relying on complex sub-structures to miniaturize the antenna, including topology optimization and meandered windings, cannot apply to DRAs. Due to the capacitive nature of the DRA modes, it is also shown that the Q factor of any DRA sub-structure will be bounded from below by that of the super-structure at frequencies below the first self-resonance of the super-structure. We demonstrate these bounding relations with numerical examples.}, journal={IEEE OPEN JOURNAL OF ANTENNAS AND PROPAGATION}, author={Yang, Binbin and Kim, Jaewoo and Adams, Jacob J.}, year={2022}, pages={59–68} }
 @article{yang_adams_2020, title={A Decoupling Network Based on Characteristic Port Modes}, ISSN={["1522-3965"]}, DOI={10.1109/IEEECONF35879.2020.9329790}, abstractNote={In this paper, we present a novel decoupling network for coupled antenna systems using characteristic port modes. Specifically, we observe that the the port response of a multiport antenna is the superposition of the characteristic modal responses, while the superposition relation for multi-port antennas can be represented as a transformer bank. By developing a transformer network that inverts the superposition relation, we realize a decoupling network for the coupled multi-port antennas. Depending on the antenna's property, this decoupling network could be a broadband, e.g. for symmetric networks, or a narrowband realization.}, journal={2020 IEEE INTERNATIONAL SYMPOSIUM ON ANTENNAS AND PROPAGATION AND NORTH AMERICAN RADIO SCIENCE MEETING}, author={Yang, Binbin and Adams, Jacob J.}, year={2020}, pages={1667–1668} }
 @article{yang_zhou_adams_2019, title={A Shape-First, Feed-Next Design Approach for Compact Planar MIMO Antennas}, volume={77}, ISSN={["1098-8963"]}, DOI={10.2528/PIERM18100903}, abstractNote={Employing characteristic mode theory (CMT), a shape-first feed-next design methodology for compact planar antennas is proposed, which facilitates rapid and systematic design of self-matched, multi-port antennas with optimal bandwidth and high isolation. First, the optimal antenna shape with multiple self-resonant modes is synthesized using a binary genetic algorithm. Then, the optimal feed positions that provide good input matching and high isolation between the excitation ports are specified using a virtual probe modeling technique. A two-port microstrip antenna with an electrical size of 0.45λd × 0.297λd is designed, fabricated and measured. The measured operating frequency is within 1% of the full wave simulation, and the overall S parameter characteristics and far field patterns agree well with the simulation result, validating our design methodology. Mutual coupling S21 < −35 dB at the center frequency is achieved in this design.}, journal={PROGRESS IN ELECTROMAGNETICS RESEARCH M}, author={Yang, Binbin and Zhou, Juncheng and Adams, Jacob J.}, year={2019}, pages={157–165} }
 @article{yang_chen_zhu_li_2019, series={Minerals Metals & Materials Series}, title={Radiation and Corrosion Resistances of 316LN Austenitic Stainless Steel by Rotationally Accelerated Shot Peening}, ISBN={2367-1181}, DOI={10.1007/978-3-030-05861-6_119}, abstractNote={A rotationally accelerated shot peening (RASP) technique was used to improve the radiation and corrosionCorrosion resistances of 316LN austenitic stainless steelAustenitic stainless steel (316LN SS). The experimental results indicated that high density nanoscale twin boundaries (NTBs) were introduced in the steelSteel after the RASP. These boundaries were found not only beneficial to enhance radiation resistance but improve the corrosion resistanceCorrosion Resistance of the steelSteel . Radiation experiments showed the average size of helium bubbles and unstable shear bands were restrained in the RASPed 316LN SS comparing to those tested in the as-received 316LN SS samples. The electrochemical test results revealed the critical pittingPitting potential and passive film resistance value of the steelSteel increased after treated by the RASP. These results shed light on radiation and corrosionCorrosion resistances robust developments in advanced nuclear materials.}, journal={TMS 2019 148TH ANNUAL MEETING & EXHIBITION SUPPLEMENTAL PROCEEDINGS}, author={Yang, Bin and Chen, Xudong and Zhu, Yuntian and Li, Yusheng}, year={2019}, pages={1251–1260}, collection={Minerals Metals & Materials Series} }
 @inproceedings{yang_adams_2017, title={Quality factor calculations for the characteristic modes of dielectric resonator antennas}, ISBN={9781946815002}, url={http://dx.doi.org/10.1109/usnc-ursi-nrsm.2017.7878293}, DOI={10.1109/usnc-ursi-nrsm.2017.7878293}, abstractNote={Characteristic mode theory (CMT) is employed to calculate the eigenmodes of dielectric objects based on the volume integral equation. With the knowledge of modal current, the quality factor (Q) of the characteristic modes are then calculated. In contrast to most conventional analysis techniques, the modal Qs are now available at any frequency, rather than only their resonant frequencies. This method offers additional information that can be used for single and multi-port dielectric resonator antenna (DRA) design and shape optimization. To verify our method, a cylindrical dielectric resonator is studied, and the Q factors at its natural resonance frequencies are compared with results from previous literature. This approach can be readily applied to geometries of arbitrary shape.}, booktitle={2017 United States National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM)}, publisher={IEEE}, author={Yang, Binbin and Adams, Jacob J.}, year={2017}, month={Jan} }
 @inproceedings{yang_adams_2016, title={A modal approach to shape synthesis and feed placement for planar MIMO Antennas}, booktitle={2016 ieee antennas and propagation society international symposium}, author={Yang, B. B. and Adams, J. J.}, year={2016}, pages={15–16} }
 @article{yang_adams_2016, title={Computing and Visualizing the Input Parameters of Arbitrary Planar Antennas via Eigenfunctions}, volume={64}, ISSN={["1558-2221"]}, DOI={10.1109/tap.2016.2554604}, abstractNote={We propose a method for modeling planar multiport antennas of arbitrary shape using characteristic mode theory (CMT) without physically including the feeds. The characteristic modes of the feed-free structure are expanded to form a basis for the eigenfields, and a virtual probe is introduced to excite the antenna. We develop a broadband multiport circuit model for the antenna impedance based on the excitation of each mode, where the feed locations only affect transformer ratios in the model, enabling design and analysis of arbitrary feed combinations over a wide frequency range. Because a CMT expansion can be computed for any planar geometry, the shape of the radiating element can also be arbitrary. While this approach is approximate, several examples are presented to demonstrate that its accuracy and flexibility make it suitable for various planar antenna design applications. With the rapid evaluation of input impedance at multiple excitation points, input parameters, such as the multiport S, Y, or Z parameters, can be plotted as a heat map on the antenna structure, facilitating planar multiport antenna optimization and feed selection.}, number={7}, journal={IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION}, author={Yang, Binbin and Adams, Jacob J.}, year={2016}, month={Jul}, pages={2707–2718} }
 @inproceedings{yang_adams_2016, title={Mode-based analytical models for arbitrary wire and planar antennas}, DOI={10.1109/eucap.2016.7481186}, abstractNote={We describe new methods to generate circuit models for arbitrary wire and planar antennas. We first use the characteristic modes of the structure to develop a set of eigenimpedances that are independent of feed position. Once the antenna's eigenimpedances are known, the input impedance can be computed for a feed placed anywhere on the structure through simple calculations (products and sums). Therefore, the input impedance at all points on the structure can be determined very quickly relative to conventional simulation methods. While this approach is inherently approximate, it provides accurate results for many topologies while requiring far fewer calculations than port simulation. Furthermore, the approach applies to multi-port antennas where the complexity of evaluating many possible port combinations greatly increases the cost of conventional port simulation.}, booktitle={2016 10th european conference on antennas and propagation (eucap)}, author={Yang, B. B. and Adams, Jacob}, year={2016} }
 @article{yang_adams_2016, title={Systematic Shape Optimization of Symmetric MIMO Antennas Using Characteristic Modes}, volume={64}, ISSN={["1558-2221"]}, DOI={10.1109/tap.2015.2473703}, abstractNote={We introduce a systematic approach to the shape optimization of compact, single-aperture MIMO antennas. Because the characteristic modes of a radiator represent its complete set of possible responses to an excitation, any port on the antenna must display the properties of a combination of one or more of these characteristic modes. By restricting our consideration to a class of symmetric antennas, the lowest order characteristic modes of a structure can be separated with practical decoupling networks, studied, and excited independently. We show that the quality factor of each characteristic mode effectively bounds the performance of any individual port excitation, and can be used to evaluate the fitness of the antenna for multiport excitation. Under this framework, we apply a genetic algorithm (GA) to synthesize low Q MIMO antennas while minimizing conductor area. Feed locations are specified on the optimized shape based on the weighted excitation strength of the desired modes, and a two-port MIMO antenna is implemented and measured, verifying the proposed theory.}, number={7}, journal={IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION}, author={Yang, Binbin and Adams, Jacob J.}, year={2016}, month={Jul}, pages={2668–2678} }
 @inproceedings{yang_adams_2015, title={Modal Q as a bounding metric for MIMO antenna optimization}, booktitle={2015 31st International Review of Progress in Applied Computational Electromagnetics (ACES) vol 31}, author={Yang, B. B. and Adams, J. J.}, year={2015} }
 @inproceedings{adams_yang_2015, title={Physics-based circuit models for MIMO antennas using characteristic modes}, booktitle={2015 ieee international symposium on antennas and propagation & usnc/ursi national radio science meeting}, author={Adams, J. J. and Yang, B. B.}, year={2015}, pages={852–853} }