In many applications, offset of the OP-AMPs should be canceled to high accuracy be accomplished. In this work, an asymmetrical differential input circuit with active DC offset rejection circuit was implemented to minimize the systematic offset of the amplifier. The proposed OP-AMPs show that the systematic offset voltages is less than 80 μV. Keywords—component; formatting; style; styling; insert

We introduce a novel scheme for spread spectrum systems, which we call the offset code spreading scheme. By employing the scheme, we can implement a directconversion receiver for a differential-binary phase shift keying system with a DC-cut high pass filter. This will allow us to eliminate the DC-offset by carrier leakage and mitigate the 1/f noise of the mixer. System simulations show that a 1...

This paper presents a feasibility study of DC offset filtering for direct-conversion UTRA-FDD/WCDMA receivers. Spectral characteristics and properties of continuous transmission facilitate the use of simple high-pass filtering and this method is evaluated in the paper. Design equations for DC offset power to down-converted signal power ratio are presented and the impact on bit error rate of hig...

A harmonic mixer for direct-conversion receivers is proposed and fabricated in a CMOS process. It is immune from both the flicker noise and self-mixing induced DC offset. Using the lateral bipolar transistor and the harmonic mixing technique, it achieves +15dB gain, 17.8dB NF at 10kHz frequency, 8.2dBm IIP3, +44dBm IIP2 and more than 30dB DC offset suppression. It consumes 2.2mW power at 3V.

This paper presents an approach for implementing continuous-time adaptive recursive filters. The resulting filters should be capable of operating on much higher signal frequencies than their digital counterparts since no sampling is required. With respect to implementation problems, the effects of DC offsets is investigated and formulae derived so that these effects can be estimated and reduced...

Electrophysiological assessment of infraslow (<0.1 Hz) brain activities such as cortical spreading depression (SD), which occurs in a number of pathologies including migraine, epilepsy, traumatic brain injury (TBI) and brain ischemia requires direct current (DC) coupled recordings of local field potentials (LFPs). Here, we describe how DC-coupled recordings can be performed using high-density i...

The double balance mixer scheme in-phase signal input and double-quadrature Local Oscillator (LO) is suggested for application on IQ direct conversion receivers. The influence of the gain and phase mismatches of splitters is investigated. It is shown that a similar scheme using square-law detectors is promising on optical applications. Introduction The increasing interest in direct conversion r...