The architecture for very-high speed DAC with medium oversampling and high resolution is discussed. The scheme uses an hybrid sigma-delta scheme that processes LSBs of the input word and obtain digital to analog conversion with an hybrid current steering DAC with dynamic element matching of MSBs and time interleaved conversion of LSBs. The return-to-zero for all elements ensures the required li...

Many long-term geomagnetic observation results recorded on photographic bromide paper have not yet been fully digitized. To that end, we developed a method to automatically convert photographic records to one-minute digital data. We applied our method to the observation records of Kakioka Magnetic Observatory and confirmed that the resolution of time and amplitude could be greatly improved by n...

The use of Sigma-Delta (Σ∆) modulation for analog-to-digital conversion (ADC) in the communication frequency range is evaluated. Two high-order multi-bit architectures are proposed to achieve +12-bit dynamic range at 4Msample/s Nyquist rate using very low oversampling ratio. They show very low sensitivity to the internal D-to-A conversion (DAC) error with no calibration required. Simulations sh...

This document describes the simulation and FPGA implementation of the IIP Radiometer Digital IF Section described in [1]. The digital IF processor presented here is a slightly different to that of [1]. The digital IF processor implemented here is illustrated in Figure 1 where there are four distinct sections; namely demultiplex, FS/4 down conversion, filtering and FS/4 up conversion. The struct...

In this paper, we analyze the effect of clock jitter on the performance of OFDM-based systems applying digital IF architecture. A bandpass Σ∆ ADC is used for the analog to digital conversion process. An accurate and realistic model of the clock jitter in bandpass Σ∆ ADC is implemented. Results from this paper show that clock jitter severely degrades OFDM system performance by introducing both p...

Frequency-to-Digital Conversion (FDC) and Artificial Neural Networks (ANNs) techniques are two powerful tools that can be used to improve the performance of measurement systems. The main advantages associated with frequency output transducers include their high noise immunity, high output signal power, wide dynamic range and simplicity of signal interfacing and coding [1-2]. The frequency-to-di...

For the analog-to-digital conversion lab, we need a resetable ramp generator. Here, we explore building a ramp generator from a current source. We show two implementations that both use a PNP current source.

Protecting signals is one of the main tasks in information transmission. A large number of different methods have been employed since many centuries ago. Most of them have been based on the use of certain signal added to the original one. When the composed signal is received, if the added signal is known, the initial information may be obtained. The main problem is the type of masking signal em...

This paper covered a series of key points in terms of 2D to 3D stereoscopic conversion. A successfully applied stereoscopic conversion approach in current visual effects industry was presented. The purpose of this paper is to cover a detailed workflow and concept, which has been successfully used in 3D stereoscopic conversion for feature films in visual effects industry, and therefore to clarif...

This thesis demonstrates that analog-to-digital (A/D) conversion at the intermediatefrequency stage of a radio is feasible for a wide range of cellular and cordless telephony standards. Placing the A/D converter as close as possible to the front end of the radio has manufacturing advantages and allows the use of sophisticated DSP algorithms which are especially usem with digitally coded transmi...