Introduction:Low-pass filters eliminate noise, and accordingly improve the quality of filtered back-projection (FBP) in the reconstruction of single photon emission computed tomography (SPECT) images. This study aimed at selection of an optimum low-pass filter for FBP reconstruction of SPECT images of small structures. Material and Methods:Sp...

a log-domain current-mode true rms-to-dc converter based on a novel synthesis of a simplified current-mode low pass filter and a two-quadrant squarer/divider is presented. the circuit employs floating gate mos (fg-mos) transistors operating in weak inversion region. the converter features low power(<1.5uw), low supply voltage (0.9v), two quadrant input current, immunity from body effect, low ci...

this paper presents a novel microstrip low-pass filter with good performance. a complete detailed theoretical analysis for the proposed filter is given using equivalent circuit models. the proposed filter applying multiple cascaded modified radial stubs resonators provides a sharp cut off frequency response that has a 185 db/ghz roll off rate. also, u-shaped attenuators provide a wide stop-band...

A simple but efficient stereo reverberation control is developed to simulate reverberation. Inspired from previous classic studies, the reverberator is built using simple digital filters, including comb filters and all-pass filters commonly used for digitally simulating reverberation. The digital reverberator incorporates low-pass filters to simulate the air and walls absorption effect, gains t...

The total variation (TV) functional is explored from a spectral perspective. We formulate a TV transform based on the second time derivative of the total variation flow, scaled by time. In the transformation domain disks yield impulse responses. This transformation can be viewed as a spectral domain, with somewhat similar intuition of classical Fourier analysis. A simple reconstruction formula ...

In this paper, a simple and intuitive technique for analyzing clock jitter effect on bandpass Continuous-Time SigmaDelta (Σ∆) modulators is introduced. The power spectral density of the jitter noise for different feedback DAC shapes are derived and compared. It is shown that DAC output signal shapes used to reduce clock jitter sensitivity in lowpass Continuous-Time Σ∆ modulators may not be suit...

In this study, a low-pass filter with coaxial transmission lines is designed and produced. The objective for designing was to utilize both low loss high breakdown voltage capability power microwave applications enable the suppression of second harmonic 4.4-6 GHz C-Band ( selected as proof concept ) signals minimal insertion loss. Microwave 3D electromagnetic simulators were used in design. desi...