This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Improved fast switching of radiofrequency (r.f.) energy via PIN-diode switches is essential for receiver protection and deadtime reduction in the design of ACERT next-generation pulsed-ESR spectrometers. Fabrication of a novel, specialized electronic driver for PIN switches has previously been accomplished within the Freed Research Group (U.S. patent #5,214,315). A unique feature of this invention is that it optimizes transition speed under reactive loading conditions typical of Si and GaAs PIN-diode arrays. We are currently upgrading the driver by modeling and specifying higher-performance power MOSFET semiconductors and reformatting the switch driver as a high-performance hybrid circuit. Integration of the discrete components comprising the switch driver onto a compact ceramic substrate will significantly improve switching speed by minimizing parasitic inductance associated with the circuit interconnects. We are employing advanced commercial software tools in order to accurately model the higher-order interconnect parasitics and semiconductor characteristics; this capability allows efficient simulation and selection of newer semiconductors best-suited to this application. It also permits accurately predicting the magnitude and effect of minute parasitic reactances, greatly reducing the time required for convergence of layout variations. Simulation studies indicate that the most recent hybrid driver design should perform at the 6 - 8 ns level for charge transfers of 15-20 nC. This figure translates to probable r.f. switching speeds in the 10 - 14 ns range for high-power silicon PIN diode arrays, or 4 - 6 ns for h.v. GaAs PIN arrays. The driver hybrid assembly is physically small and can therefore be situated in close proximity to its associated PIN arrays, minimizing detrimental transmission-line effects and electromagnetic interference. We are evaluating further candidate PIN devices and plan to requisiton the hybrid drivers once the PIN diodes have been characterized in the context of our ongoing microwave spectrometer development.

National Institute of Health (NIH)
National Center for Research Resources (NCRR)
Biotechnology Resource Grants (P41)
Project #
Application #
Study Section
Special Emphasis Panel (ZRG1-BCMB-K (40))
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Cornell University
Schools of Arts and Sciences
United States
Zip Code
Jain, Rinku; Vanamee, Eva S; Dzikovski, Boris G et al. (2014) An iron-sulfur cluster in the polymerase domain of yeast DNA polymerase ?. J Mol Biol 426:301-8
Pratt, Ashley J; Shin, David S; Merz, Gregory E et al. (2014) Aggregation propensities of superoxide dismutase G93 hotspot mutants mirror ALS clinical phenotypes. Proc Natl Acad Sci U S A 111:E4568-76
Georgieva, Elka R; Borbat, Peter P; Ginter, Christopher et al. (2013) Conformational ensemble of the sodium-coupled aspartate transporter. Nat Struct Mol Biol 20:215-21
Airola, Michael V; Sukomon, Nattakan; Samanta, Dipanjan et al. (2013) HAMP domain conformers that propagate opposite signals in bacterial chemoreceptors. PLoS Biol 11:e1001479
Airola, Michael V; Huh, Doowon; Sukomon, Nattakan et al. (2013) Architecture of the soluble receptor Aer2 indicates an in-line mechanism for PAS and HAMP domain signaling. J Mol Biol 425:886-901
Sun, Yan; Zhang, Ziwei; Grigoryants, Vladimir M et al. (2012) The internal dynamics of mini c TAR DNA probed by electron paramagnetic resonance of nitroxide spin-labels at the lower stem, the loop, and the bulge. Biochemistry 51:8530-41
Smith, Andrew K; Freed, Jack H (2012) Dynamics and ordering of lipid spin-labels along the coexistence curve of two membrane phases: an ESR study. Chem Phys Lipids 165:348-61
Yu, Renyuan Pony; Darmon, Jonathan M; Hoyt, Jordan M et al. (2012) High-Activity Iron Catalysts for the Hydrogenation of Hindered, Unfunctionalized Alkenes. ACS Catal 2:1760-1764
Gaffney, Betty J; Bradshaw, Miles D; Frausto, Stephen D et al. (2012) Locating a lipid at the portal to the lipoxygenase active site. Biophys J 103:2134-44
Dzikovski, Boris; Tipikin, Dmitriy; Freed, Jack (2012) Conformational distributions and hydrogen bonding in gel and frozen lipid bilayers: a high frequency spin-label ESR study. J Phys Chem B 116:6694-706

Showing the most recent 10 out of 72 publications