Analysis of High-Order IF Wideband Group Delay Equalization for Satellite Receiver

Abstract

For the Satellite Navigation Receiver of CDMA system, the circuit which is passive should have well characteristics on amplitude and phase within the pass band, especially in anti-jamming receiver. But the filters in the last cascade of reviver's analog circuits are primary causes of non-ideal channel characteristics so that group delay equalization is efficient and necessary. Narrowband group delay equalization, which can't satisfy wideband filter, has been improved to a wideband group delay equalization of satellite navigation receiver. The thesis analyzes and designs a high-order equalization based on Centro Symmetric Equalization Method. By simulating and producing actual circuit, the performance of third-order and fifth-order group delay equalization networks are compared and analyzed. Finally, the fifth-order wideband group delay equalization circuit is cascaded with the filter of navigation receiver that the maximum group delay of pass band has been reduced to 5 ns between full bandwidth, 10% of before. This method has been applied on a wideband high measurement accuracy anti-jamming navigation receiver and improved the group delay characteristics from the analog frond-end.