Conference paper
2 GHz self-aligning tandem A/D converter for SAR
A new generation of the Danish synthetic aperture radar system (EMISAR) is under development targeting a bandwidth of 800 MHz and a corresponding range resolution of around 25 cm. Two alternative approaches to achieve the wide bandwidth are considered. One is to use analog I/Q demodulation before digitizing, and the other is to digitize the signal before digital I/Q demodulation.
In both cases the digitizing may be performed by a digital front end (DFE) with two parallel analog-to-digital-converters (ADCs) sampling at 1 GHz in phase or in anti-phase respectively, provided the analog bandwidth of the ADC is sufficient. In the first case each ADC has to digitize a 0-400 MHz signal, and in the second case both ADCs have to digitize a 100-900 MHz signal.
In both cases the sampling time alignment is a critical parameter. The paper addresses some aspects of ADC alignment in the implementation of a DFE for the EMISAR system.
| Language: | English |
|---|---|
| Year: | 2001 |
| Pages: | 2028-2030 |
| Proceedings: | 2001 Geoscience and Remote Sensing Symposium |
| ISBN: | 0780370317 and 9780780370319 |
| Types: | Conference paper |
| DOI: | 10.1109/IGARSS.2001.977892 |
| ORCIDs: | Søbjærg, Sten Schmidl |
0 to 400 MHz 1 GHz 100 to 900 MHz 2 GHz 800 MHz ADC Bandwidth Correlators Delay Demodulation EMISAR FPGA Frequency Pulse measurements Radar measurements SAR Sampling methods Stochastic processes UHF UHF circuits Voltage analog I/Q demodulation analogue-digital conversion bandwidth correlation measurement demodulation digital I/Q demodulation digital front end field programmable gate array modulation parallel analog-to-digital-converters range resolution sampling time alignment self-aligning tandem A/D converter signal sampling synthetic aperture radar synthetic aperture radar system
