This paper presents a fully differential power amplifier (PA) with high efficiency and linearity. To improve the linearity, an optimum gate bias is applied for the cancellation of the nonlinear harmonics. The amplifier delivers a 6 dB of power gain. The signal noise distortion and total harmonic distortion of 55.68 dB and 0.144% has been shown. The compensation characteristics of the circuit ha...

Performance analyses are presented theoretically on OFDM-PON working in IQ modulationheterodyne detection scheme for downstream and in intensity modulation-homodyne detection scheme for upstream which include the characterization of non-linear distortion in IQ modulator, pilot light multiplexing for optical phase noise cancellation in ONU receiver, heterodyne detection with LO provided by shari...

BSIM4 model is not suitable for distortion analysis of circuits with bias point VDS 1⁄4 0, such as passive mixers and RF switches, due to discontinuities in higher order derivatives. Surface potential based PSP model has continuous derivatives to at least third-order, and is therefore suitable for intermodulation products simulation. This paper presents the case study of BSIM4 to PSP model conv...

The central question of this paper is: can we enhance the spectral purity of nonlinear circuits by using polyphase multipath circuits? The basic idea behind polyphase multipath circuits is to split the nonlinear circuits into two or more paths and exploit phase differences between these paths to cancel undesired distortion products. It turns out that it is very well possible to use polyphase mu...

In this paper, we expand the knowledge regarding the problems of two-channel (or stereophonic) echo cancellation. The major difference between two-channel and the single-channel echo cancellation is the problem of nonunique solutions in the twochannel case. In previous work, this nonuniqueness problem has been linked to the coherence between the two incoming audio channels. One proven solution ...

This paper proposes an efficient way of integrating acoustic echo canceller (AEC) and background noise reduction (NR) modules for voice communication systems. The main strategy for designing a standalone AEC or NR module is straightforward, but it is not easy to integrate two modules in a single system because of the undesired effect caused by the nonlinear nature of each module’s output. The p...

This report presents a novel, cascaded approach to non-linear acoustic echo cancellation (AEC). The loudspeaker enclosure microphone (LEM) system is divided into two blocks: non-linear clipping and power filtering, and a conventional, linear AEC. They represent the non-linear amplifier and loudspeaker and linear acoustic channel and up-link path in a typical mobile communication scenario. We pr...

Digital holography is a three-dimensional (3D) measurement technique that can be used to quantitatively determine the size and 3D location of objects inside field-of-view. However, in systems where refractive index gradients are present, variations optical phase due high-speed shock-waves or low-speed thermal cause distortions obscure objects. While techniques like phase-conjugate digital in-li...

A CMOS transconductor for multi-mode application is presented. The transconductor includes a voltage-to-current converter and a current multiplier. Voltage-to-current conversion employs linear region MOS transistors, and the conversion features high linearity over a wide input swing range. The current multiplier, which operates in the weak inversion region, provides a wide transconductance tuni...