Jennifer T. Bernhard

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Increasingly stringent design constraints imposed by compact wireless devices for telecommunications, defense, and aerospace systems require the miniaturization of antennas. Unlike most electronic components, which benefi t from decreased size, antennas suffer limitations in gain, effi ciency, system range, and bandwidth when their size is reduced below a(More)
Figure 1 . a) Optical image of a rollerball pen loaded with a conductive silver ink. The background shows conductive text written on Xerox paper. b and c) SEM images of the side and top views of the rollerball pen. d) Optical image of the rollerball pen tip, captured during writing a conductive silver track on a Xerox paper. Printed electronics constitute(More)
This paper describes a proposed testbed named Illinois Wireless Wind Tunnel (iWWT). The goal of the testbed is to implement "scaled" versions of wireless networks for the purpose of accurate repeatable evaluation of wireless protocols. The testbed will be implemented in an electromagnetic anechoic chamber at the University of Illinois at Urbana-Champaign.(More)
| This paper provides an overview of how our access to the electromagnetic spectrum has evolved and will continue to expand over time. We first focus on the historical origins of technological and regulatory choices, and provide some insight into how these choices have impacted the efficiency with which we currently utilize the spectrum, and how we can(More)
This letter proposes a concept for frequency-reconfigurable slot antennas enabled by pressure-driven capacitive microfluidic switches. The switches are operated by pneumatically displacing a plug of eutectic gallium indium alloy (EGaIn) within an air-filledmicrochannel that traverses the slot orthogonally. Frequency reconfigurability is achieved by altering(More)
RF MEMS switches are used in many applications and also can be used to achieve reconfigurability of various RF systems and in particular, that of minute sized antenna structures and systems. In the case of micro machined antennas, which usually have low voltage signals, RF MEMS switches with low actuation voltage are highly required for achieving(More)
The continued growth of wireless communication in both the commercial and defense sectors requires new kinds of enabling technology for antennas and RF circuitry to provide high speed, high reliability performance. The development of this technology requires contributions from industry, the military, and academia to meet the challenges presented by(More)