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.
|Title of host publication||Proceedings of the IEEE 2001 International Geoscience and Remote Sensing Symposium|
|Publication status||Published - 2001|
|Event||IEEE 2001 International Geoscience and Remote Sensing Symposium - Sydney, Australia|
Duration: 9 Jul 2001 → 13 Jul 2001
|Conference||IEEE 2001 International Geoscience and Remote Sensing Symposium|
|Period||09/07/2001 → 13/07/2001|