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IEEE MTT-S International Microwave Symposium Digest
Scott, Sean M.; Nordquist, Christopher N.; Leonhardt, Darin L.; Jordan, Tyler S.; Rodenbeck, Christopher T.
The concept for a new, frequency-selective limiting filter is presented. This is accomplished by placing a phase change vanadium dioxide (VO2) film at the proper node of the filter. When the high-powered microwave signal reaches a certain threshold, the VO2 undergoes a phase transition from the monoclinic "insulator state" to the tetragonal "metallic state". This crystallographic change is accompanied by a 3 order of magnitude drop in the film's resistivity, and creates a short circuit at a section of the filter, changing a pole to a zero, and rejecting further undesirable high-powered signals from damaging sensitive receiver components. This paper details the design and simulation of the filter, along with measurement results from VO2 films and the filter element. This filter element begins rejecting at about 2 W input power, with isolation of over 16 dB to over 23 W input power, and is unaffected by an out-of band interferer of over 25 W. The architecture presented allows for filter banks capable of automatically-rejecting interferers, yet allowing signals of interest to pass. © 2013 IEEE.
Nordquist, Christopher N.; Leonhardt, Darin L.; Rodenbeck, Christopher T.
IEEE Transactions on Electron Devices
Jordan, Tyler S.; Leonhardt, Darin L.; Rodenbeck, Christopher T.; Wolfley, Steven L.; Nordquist, Christopher N.
IET Electronics Letters
Rodenbeck, Christopher T.; Young, Derek Y.
Nordquist, Christopher N.; Leonhardt, Darin L.; Jordan, Tyler S.; Rodenbeck, Christopher T.
Scott, Sean M.; Nordquist, Christopher N.; Cich, Michael C.; Jordan, Tyler S.; Rodenbeck, Christopher T.
Knudson, R.T.; Sandoval, Charles E.; Rodenbeck, Christopher T.
Electronics Letters
Rodenbeck, Christopher T.
Electronics Letters
Rodenbeck, Christopher T.
IEEE Transactions on Antennas and Propagation
Rodenbeck, Christopher T.
A class of planar, electrically-small UHF antennas suitable for direct integration with electronic components such as batteries is introduced. The new design approach combines a meander line section and a capacitive strip section. The geometries of the two sections can together be scaled in size over a wide range of planar form factors while still maintaining self-resonance and practically realizable line widths and spacings. No external matching network is required. Moreover, batteries can be mounted above or below the capacitive strip section, significantly reducing the total size of a wireless device. Three designs are demonstrated on printed circuit board at 433 MHz. Measurements show that the antennas provide good gain and excellent bandwidth, omnidirectional radiation patterns, and electrically small size. The results of this work have numerous uses in radiofrequency identification (RFID). © 2006 IEEE.
IEEE Transactions on Antennas and Propagation
Rodenbeck, Christopher T.
Feldner, Lucas M.; Rodenbeck, Christopher T.
Proposed for publication in the IEEE Transactions on Antennas and Propagation.
Rodenbeck, Christopher T.
Feldner, Lucas M.; Rodenbeck, Christopher T.
Proposed for publication in IEEE Transactions on
Antennas and Propagation.
Rodenbeck, Christopher T.
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