Martin C. Peckerar

Solar Spectrum Rectification Using Nano-Antennas and Tunneling Diodes

Our goal is to develop a rectifying antenna (rectenna) applicable to solar spectrum energy harvesting. In particular, we aim to demonstrate viable techniques for converting portion of the solar spectrum not efficiently converted to electric power by current photovoltaic approaches. Novel design guidelines are suggested for rectifying antenna coupled tunneling diodes. We propose a new geometric field enhancement scheme in antenna coupled tunneling diodes that uses surface plasmon resonances. For this purpose, we have successfully implemented a planar tunneling diode with polysilion/SiO2/polysilcon structure. An antenna coupled asymmetric tunneling diode is developed with a pointed triangle electrode for geometric field enhancement. The geometrically asymmetric tunneling diode shows a unique asymmetric tunneling current versus voltage characteristic. Through comparison with crossover tunneling diodes, we verified that the current asymmetry is not from the work function difference between the two electrodes. Results of RF rectification tests using the asymmetric diode demonstrate that our approach is practical for energy harvesting application. Furthermore, we describe how surface plasmons can enhance the electric field across the tunnel junction, lowering the effective turn-on voltage of the diode, further improving rectification efficiency.

Nondestructive characterization of oxygen‐ion‐implanted silicon‐ on‐insulator using multiple‐angle ellipsometry

Silicon‐on‐insulator formed by high‐dose and high‐energy oxygen ion implantation in silicon, called SIMOX (separation by implanted oxygen), has been characterized nondestructively by multiple‐angle ellipsometry using a He–Ne laser at 632.8 nm. A multilayered model exhibiting two interlayers, one between the top silicon layer and the buried oxide layer and the other between the buried oxide and the substrate silicon, offers a simple representation of SIMOX. The difference between low‐temperature furnace anneal (1150u2009°C) and an additional high‐temperature rapid thermal anneal (1150+1350u2009°C) on as‐implanted wafers is shown by the better agreement between the theoretical model and the experimental results for the high‐temperature annealed SIMOX sample.

Ultra low power phase detector and phase-locked loop designs and their application as a receiver

In this paper, we present a new low power down-conversion mixer design with single RF and LO input topology which consumes 48µW power. Detailed analysis of the mixer has been provided. Using the presented mixer as a phase-detector, a low power phase-locked loop (PLL) has been designed and fabricated. A PLL based receiver architecture has been developed and analyzed. The circuit has been fabricated through 0.13µm CMOS technology. Dissipating 0.26mW from a 1.2V supply, the fabricated PLL can track signals between 1.62 and 2.49GHz. For receiver applications, the energy per bit of the receiver is only 0.26nJ making it attractive for low power applications including wireless sensor networks.

Effects of cryogenic temperatures on small-signal MOSFET capacitances

Many analog electronics, such as the front-end circuitry of audio, video and radio frequency amplifiers and active filters, involve small signal transistor operation. Under small signal operation, a DC bias or quiescent point is first established for the circuit. Then a small AC signal is applied, giving rise to a small variation about the operating point. The main idea behind small signal operation is that this variation is sufficiently small to assume a linear response of the electronics.