An improved arctangent algorithm based on phase-locked loop for heterodyne detection system<xref rid="cpb_28_3_030701fn1" ref-type="fn">*</xref><fn id="cpb_28_3_030701fn1"><label>*</label><p>Project supported by Key Research Program of Frontier Science, Chinese Academy of Sciences (Grant No. QYZDB-SSW-SLH014) and the Yong Scientists Fund of the National Natural Science Foundation of China (Grant No. 61205143).</p></fn>

An improved arctangent algorithm based on phase-locked loop for heterodyne detection system**

Project supported by Key Research Program of Frontier Science, Chinese Academy of Sciences (Grant No. QYZDB-SSW-SLH014) and the Yong Scientists Fund of the National Natural Science Foundation of China (Grant No. 61205143).

Yan Chun-Hui^{1, 2}, Wang Ting-Feng^{1, †}, Li Yuan-Yang¹, Lv Tao^{1, 2}, Wu Shi-Song^{1, 2}

(a), (b) The demodulation output results without PLL and (c) power spectrum when the signal to noise ratio is equal to −33.95 dB.