In this paper, we investigate the parameters affecting Total Harmonic Distortion (THD) and Power Supply Rejection Ratio (PSRR) in PWM Class D Amplifiers (CDAs) on the basis of linear models with feedback. From our mathematical analysis, we show that the THD of a PWM Class D amplifier with feedback can be improved by increasing the gain of the integrator through adding another amplifier at the o...

To ensure that linearity is maintained to a high degree, it is necessary to examine the nature of amplifier distortion. Audio amplifier distortion is of concern for many years. The conventional feedback techniques used at audio frequencies are not applicable to many RF amplifiers due to following problems: 1. Stability at high bandwidth; 2. Cost for high gains in RF stages. Memory less or Insta...

Modeling high-order nonlinear systems is an important issue in audio signal processing. It may be employed in real-time emulation of analog nonlinear systems, such as guitar distortion and amplifiers or other vintage electronic audio systems. This paper proposes a new method for obtaining an economical black-box model of nonlinear systems using the swept-sine technique, which extracts the harmo...

In this paper, we describe technology and experience with an experimental personal information manager, which interacts with the user primarily but not exclusively through speech recognition and synthesis. This device, which controls a client PDA, is known as the Personal Speech Assistant (PSA). The PSA contains complete speech recognition, speech synthesis and dialog management systems. Packag...

The distortion produced by a typical solid-state Class-B power amplifier is shown to consist of eight mechanisms, all of which may coexist and whose distortion products overlap to give a complex result. Methods for isolating each mechanism for study, and minimising its contribution, are given. If the avoidable distortions are designed out, Class-B amplifiers of unusually low distortion (Below 0...

We demonstrate the generation of broadband continuous-wave optical squeezing from 280 Hz-100 kHz using a below-threshold optical parametric oscillator (OPO). The squeezed state phase was controlled using a noise locking technique. We show that low frequency noise sources, such as seed noise, pump noise, and detuning fluctuations, present in optical parametric amplifiers, have negligible effect ...

This paper discusses the design of low-voltage low-power fully-integratable automatic gain controls. Four different AGCs are presented, all consisting of three elementary building blocks: a controlled amplifier, a comparator and a voltage follower. Their design is treated separately. As an example, the final section describes an automatic gain control for hearing instruments. INTRODUCTION Low-v...

This paper proposes a trigonometric functional extension, hereafter named the Fourier model, as an alternative framework to the Volterra approach for non-linear systems modelling. This work is focused on the general advantages that trigonometric functionals show in adaptive implementations and also on the possibility they provide to reuse well-known linear processing tools in a non-linear conte...