Humans routinely produce acoustical energy at frequencies above 6 kHz during vocalization, but this frequency range is often not represented in communication devices and speech perception research. Recent advancements toward high-definition (HD) voice and extended bandwidth hearing aids have increased the interest in the high frequencies. The potential perceptual information provided by high-fr...

The charge transport properties of CdTe/CdS solar cells deposited by radio frequency (RF) sputtering have been investigated and presented in this article. The temperature dependent current-voltage characteristics of the devices under dark condition were carried out in the temperature range 240-340 K. The capacitance of the devices at various frequencies was also investigated.

Most demonstrations in silicon photonics are done with single devices that are targeted for use in future systems. One of the costs of operating multiple devices concurrently on a chip in a system application is the power needed to properly space resonant device frequencies on a system's frequency grid. We asses this power requirement by quantifying the source and impact of process induced reso...

We have employed a chip-bending method to exert continuous and reversible control over the tensile stress in doubly clamped nanomechanical beam resonators. Tensile stress is shown to increase the quality factor of both silicon nitride and single-crystal silicon resonators, implying that added tension can be used as a general, material-independent route to increased quality factor. With this dir...

The realization of acoustic devices analogous to electronic systems, like diodes, transistors, and logic elements, suggests the potential use of elastic vibrations (i.e., phonons) in information processing, for example, in advanced computational systems, smart actuators, and programmable materials. Previous experimental realizations of acoustic diodes and mechanical switches have used nonlinear...

The articles in this special section focus on nanoscale ferroelectrics for advanced electronics and microwave applications. THE MOST RECENT DEVELOPments research into ferroelectric materials, including those that are possibly compatible with CMOS technology, will make it possible to use the substances as widespread insulating-gate dielectrics microprocessors largescale integrated circuits. As a...

This paper presents a dual band aperture coupled stacked microstrip antenna with the introduction of an air gap 3 mm between the ground plane and the upper layer substrate for WLAN applications. The nominal antenna has – 10 dB return loss bandwidth of 134.8 MHz and 384.9 MHz at lower band resonant frequency of 3.905 GHz and upper band resonant frequency of 5.36 GHz respectively. The gain of the...

Our previous work demonstrated the advantages of MEMS vibratory gyroscopes with 1 degree of freedom (DOF) drive and 2-DOF sense modes which were shown to be robust to temperature drifts. These devices were designed with frequencies below 1 kHz; many applications, however, require gyroscopes with operational frequencies above 1 kHz for the rejection of ambient vibrations. This paper discusses th...

Modern radio frequency and mixed signal circuit design has increasingly relied on compound semiconductor devices to push operating frequencies deep into millimeter-wave range. InP/InGaAs/InP heterojunction bipolar transistors are capable of achieving both a unity current gain frequency (fT) and maximum frequency of oscillation (fMAX) in excess of 300GHz as well as high linearity and good therma...