A simple non-linear network for amplitude stabilization in harmonic quadrature oscillator (QO) is analyzed. The oscillation startup conditions for QO topology with two operational amplifiers are used for amplitude adjustment by element values. A closed form expression for the amplitude setting resistance is derived. Total harmonic distortion (THD) is expressed as closed form function of the est...

This note discusses distortion in JFET amplifiers and how to operate a JFET amplifier with low distortion. JFETs are typically used in the first stage of an amplifier where the signal amplitude is so small (microvolts up to maybe a few millivolts) that nonlinear effects are negligible. The distortion becomes significant at larger amplitudes where JFETs are not normally used–at least in open-loo...

Amplitude modulation systems are used in many areas of engineering, especially communication based disciplines. Typical systems have low-level signals which encode the desired information to be transmitted. These low-level signals are usually not of adequate power to transmit the desired information across a target medium, thus requiring modulation and power amplification. In general, two goals...

A time and frequency-domain analysis is made of the effects of averaging and sampling methods used for constructing magnetic-observatory hourly data values. Using 1min data as a proxy for continuous, geomagnetic variation, we construct synthetic hourly values of two standard types: instantaneous “spot” measurements and simple 1-h “boxcar” averages. We compare these average-sample types with oth...

Many analog-to-digital converter applications require low distortion for a very wide dynamic range of signals. Unfortunately, the distortion caused by digitizing an analog signal increases as the signal amplitude decreases, and is especially severe when the signal amplitude is of the same order as the quantizing step. In digital audio applications, for example, low-level signals occur often, so...

In the guinea pig it has been shown that the nonlinear derived transient evoked otoacoustic emission (TEOAEnl) is comprised of significant amounts of intermodulation distortion energy. It is expected that intermodulation distortion arising from a nonlinear distortion mechanism will contribute to the overall TEOAE in a stimulus-level-dependent manner, being greatest when basilar-membrane vibrati...

The use of High Power Amplifiers (HPA) in digital communications is plagued with non-linear (AM/AM and AM/PM) distortion. This is specially acute for those modulations that are not constant amplitude, such as OFDM or MQAM. We present a pre-distortion algorithm that, in contrast to previously researched architectures, is unconditionally convergent.

The traditional distortion measurement transforms the time signal into the frequency domain to separate fundamental, harmonic and intermodulation components. This technique considers only the mean power in the analyzed interval and neglects the phase information. A new technique for the measurement of the signal distortion in time domain is presented that exploits both amplitude and phase infor...