A Low Complexity, Low Spur Digital IF Conversion Circuits for High-fidelity GNSS Signal Playback

作者：Su Fei^*; Ying Rendong

来源：Photoelectronic-Technology-Committee Conference, 2015-11-15 To 2015-11-28.

DOI：10.1117/12.2229731

• Intermediate frequency GNSS signal
• IF conversion
• high-fidelity playback
• SFDR

A low complexity high efficiency and low spur digital intermediate frequency (IF) conversion circuit is discussed in the paper. This circuit is key element in high-fidelity GNSS signal playback instrument. We analyze the spur performance of a finite state machine (FSM) based numerically controlled oscillators (NCO), by optimization of the control algorithm, a FSM based NCO with 3 quantization stage can achieves 65dB SFDR in the range of the seventh harmonic. Compare with traditional lookup table based NCO design with the same Spurious Free Dynamic Range (SFDR) performance, the logic resource require to implemented the NCO is reduced to 1/3. The proposed design method can be extended to the IF conversion system with good SFDR in the range of higher harmonic components by increasing the quantization stage.

• 出版日期2016
• 单位上海交通大学