|
Institute of scientific instruments
|
|
- Department: Magnetic Resonance and Bioinformatics
- Team: Measurement and Data Processing in Medicine
- Interests:
|
|
ADC (Analog-to-Digital Converters), DDC (Digital Down Converters), DSP.
|
Toolboxes for COM, LPT, GPIB and direct I/O control under Win95/98.
|
Universal Serial Bus controllers, POSUSB driver, USBCheck tool.
|
Programmable logic ICs, VHDL, JTAG, ISP.
|
![Papers:](pape.jpg)
Copyright (2005) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.
The following article appeared in [I. Viscor et al., Rev. Sci. Instrum. 76, 115103 (2005)] and may be found at I. Viscor et al., Rev. Sci. Instrum. 76, 115103 (2005).
11/05 Clock signal requirement for high-frequency, high dynamic range
acquisition systems .pdf (118k)
Analog-to-digital converters (ADC's) are increasingly replacing mixers in frequency conversion
schemes. To achieve superior performances, in terms of bandwidth and dynamic range, a nearly
ideal ADC clock is needed, with a spectral purity higher than the reference signal of the classical
mixing scheme. These requirements of spectral purity for the ADC clock are discussed by analyzing
in detail the nonuniform sampling process and by characterizing an actual acquisition system. The
effect of clock phase imperfections on the output is proportional to the input frequency over
sampling frequency ratio. Moreover, at the output we may have a multiple folding of the phase jitter
spectrum. These effects are illustrated by three sets of measurements performed using our system:
transfer of spurious clock components, aliasing of these components, and transfer of clock phase
noise. (C) 2005 American Institute of Physics.
05/01 Phase Noise Measurement .pdf (259k)
The analysis of the phase noise is presented. The phase fluctuation can be described of either standard deviation of the phase or time jitter or in detail as signal's spectrum. The digital receiver is proposed for the phase noise measurements.
(Radioelektronika'01)
09/00 Two-channel digital receiver as a measurement unit .pdf (130k)
A digital receiver was proposed (AD6644, AD6620, ADSP2181). This paper discusses the critical hardware
sections, the limiting system parameters and the first measurements. (Radioelektronika'00)
05/00 Gray counter in VHDL .pdf (96k)
This paper presents the simple structural description of the Gray counter with
variable width in VHDL. (Student FEI 2000)
Cited by:
VHDL.ORG
Scalable Gray Code Counter - US patent
06/99 The digital receiver utilizing AD6620 for NMR ... /in Czech/ .pdf (127k)
This paper describes a new digital receiver unit using digital down converter AD6620. Some technical problems with utilizing this circuit are figured.
(Sbornik studentu a doktorandu'99)
04/99 DSP and digital down conversion .pdf (73k)
The comparison of three single chip digital down converters
(HSP50016, HSP50214, AD6620), their parameters, features and critical sections are presented.
(Radioelektronika'99)
|
|
|
|
|
|
|
|
(+420) 541 514 305
(+420) 541 514 404
ivovi(at)isibrno.cz
23037027
|
(30.3.2000)
| |
|
|