Analysis of High-Order IF Wideband Group Delay Equalization for Satellite Receiver
Chen Lei, Li Pengpeng, Yiwei Wu, Liu Zhijun, Gang Ou · 2013
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.