Due to their high stiffness, small dimensions, and low mass, piezoelectric stack actuators are capable of developing large displacements over bandwidths of greater than 100 kHz. However, due to their large electrical capacitance, the associated driving amplifier is usually limited in bandwidth to a few kilohertz or less. In this paper the limiting characteristics of piezoelectric drives are ide...

An analog line driver for video applications is presented. Utilizing a class-AB error amplifier structure, the design achieved 1.2–V peak-to-peak output swing with better than 42-dB linearity for frequencies up to 5 MHz. An adaptive tuning scheme for output impedance matching using peak detection is used to provide uniform performance across line impedance variations. The circuit is designed in...

We describe a high impedance audiofrequency preamplifier and present au-diofrequency noise spectra for 2N4416 and U311 JF'ET's, in a temperature range from room temperature to 80O.K. It is found that optimum noise performance is obtained at-140'K. We present an analysis of some of the sources of noise. Amplifier input capacitance is a.lso measured and discussed.

Results of design and simulation of a 0.2 THz traveling-wave-tube vacuum power amplifier with a sheet electron beam and grating slow-wave structure (SWS) are presented. Electromagnetic properties of the SWS such as dispersion and interaction impedance are calculated. Smallsignal and large signal gain curves are studied.

The 2.8 Megahertz (MHz) cathode-follower RF amplifier system and ferrite-loaded gap assembly for the Proton Storage Ring (PSR) were improved as part of the Los Alamos Neutron Science Center (LANSCE) upgrade for a Short Pulse Spallation Source (SPSS) [1]. The commissioning of PSR commenced in July of 1998. The performance of the cathode-follower amplifier system and gap was measured with as much...

We present a new method for detecting and identifying bacteria by measuring impedance fluctuations (impedance noise) caused by ion release by the bacteria during phage infestation. This new method significantly increases the measured signal strength and reduces the negative effects of drift, material aging, surface imperfections, 1/f potential fluctuations, thermal noise, and amplifier noise. C...

High-resolution electronic interface circuits for transducers with nonlinear capacitive impedance need an operational amplifier, which is stable for a wide range of load capacitance. Such operational amplifier in a conventional design requires a large area for compensation capacitors, increasing costs and limiting applications. In order to address this problem, we present a gain-boosted two-sta...

Coupled electro-thermal simulations are performed to demonstrate predictive design of microwave devices. These simulations are based on an original, fully physical, thermal impedance matrix approach, capable of describing 'nearly exactly' time-dependent heat flow in complex 3-dimensional systems, whilst requiring no model reduction for electro-thermal CAD. This thermal model is validated by the...

We present the results of measurements of the scattering parameters of microstrip amplifiers MSAs based on the dc superconducting quantum interference device. The amplifier input impedance is poorly matched to typical transmission line impedances, resulting in high input return loss around 2 dB. We show that negative feedback can lower the MSA input impedance to achieve a robust match to 50 . I...

The top shows current source amplifiers used with a loop array, the bottom shows ultra-low output impedance amplifiers used with a partially decoupled rung array. The current source amplifiers provide higher levels of decoupling, but are unable to generate as much current as the ultra-low output impedance amplifiers. 7333 A Comparison of Isolating Amplifier Architectures Neal Hollingsworth, Kat...