Digital wireless communication applications such as UWB and WPAN necessitate low-power high-speed ADCs to convert RF/IF signals into digital form for subsequent baseband processing. Considering latency and conversion speed, flash ADCs are often the most preferred option. Generally, flash ADCs suffer from high power consumption and large area overhead. On the contrary, SAR ADCs have low power di...

This paper proposes a design method of separable denominator 2-D variable digital filters with high frequency tuning accuracy. In the proposed method, a parallel allpass structure with complex coefficients is used as a prototype structure of the 2-D variable digital filters. The proposed 2-D variable digital filters are composed of first-order complex allpass sections. To improve the frequency ...

Two matrix equations, Pascal matrix equation and inverse Pascal matrix, are derived and demonstrated in this work. These matrix equations are used for making a conversion and inversion between the coefficients of an analog low pass filter transfer function H(s) and a digital transfer function H(z). The involving of the Pascal’s triangle in both matrix equations is helpful, easier to transform b...

Land use change may influence many natural phenomena and ecological processes, including runoff, soil erosion, sedimentation and soil conditions. Decreasing of forest area in the North of Iran is one of the critical problems in recent years. The aims of this study are to detect land use changes between 1967 to 2002 using satellite images of Land Sat 7 ETM+ (2002), aerial photos and digital topo...

A low power, wideband transmitter architecture utilizing ∆Σ direct digital modulation of an RF carrier is presented. Spurious signals associated with direct digital-RF conversion are eliminated through integration of a self-tuned passive LC bandpass filter. The digital-RF modulator is intended for OFDM systems and can provide data rates greater than 1 Gb/s using a bandwidth of 200 MHz centered ...

Digital libraries are here to stay, and the conversion of traditional to digital is inevitable. Appropriate care should be taken to develop systems and managerial skills as well. Globalisation of the digital concept will not be possible until we overcome the technological gap between developed and developing countries. Measures are needed to overcome the menace of computer viruses and also unau...