ADC BIT NUMBER AND INPUT POWER NEEDED, IN NEW RADIO-ASTRONOMICAL APPLICATIONS |
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| Germano Bianchi, Federico Perini, Claudio Bortolotti, Jader Monari, Stelio Montebugnoli, Mauro Roma |
- Abstract:
- For the most part, so far radio astronomy observations have been performed in protected frequency bands, reserved by ITU for scientific purposes. This means that, ideally, only the amplified equivalent system noise is present at the end of the receiver chain (i.e. the ADC input). So, typically, only a few bits are necessary to describe the signal (VLBI signals are digitised with only 2 bits), but today astronomers, in order to get more sensitivity and to boldly observe where no one has observed before, would like to study the radio sky even outside the protected bands. In these cases, a lot of man-made signals, coming both from terrestrial and space radio communication systems, are added to the very weak sky noise. For the first time, radio telescope designers must take in account the problem of the A/D converter dynamic range, since the increase of the total received power could lead the A/D to saturation. Here, a procedure to estimate the required number of bit (resolution and dynamic) and the input power level of an A/D converter, is described and applied to a new radio astronomical system which is under development at the Medicina radio observatory (Italy).
- Download:
- IMEKO-IWADC-2008-167.pdf
- DOI:
- -
- Event details
- IMEKO TC:
- TC4
- Event name:
- IWADC 2008
- Title:
13th IMEKO TC4 Workshop on ADC Modelling and Testing IWADC (together with XVIth IMEKO TC4 International Symposium on Electrical Measurements and Instrumentation) (IWADC)
- Place:
- Florence, ITALY
- Time:
- 22 September 2008 - 24 September 2008