【摘要】 在无合作目标相位式激光测距中,为了提高测程和改善信噪比,提出一种基于雪崩光电二极管的电外差测量技术。在该方法中,雪崩光电二极管通过电注入法可直接被作为混频器,它接收到的回波光信号在转换成电流信号时直接和一本振信号混频产生低频信号。实验结果表明,该方法可有效改善雪崩光电二极管输出信号的信噪比,提高无合作目标相位式激光测距的测程。更多还原

【Abstract】 A heterodyne photo detection method is proposed in order to improve the signal to noise ratio of a frequency-modulated-continuous-wave (FMCW) laser range finder. For this purpose, the non-linearity of the current-voltage characteristic of an avalanche photodiode (APD) is used. The photoelectric current is mixed with a local oscillator (LO) signal inside the APD working as an optoelectronic mixer. The signal from the LO can be injected inside the APD by an electrical channel. Experimental results are in agreement with the theoretical analysis, and this method shows that it can greatly improve the measurement distance in phase-shift laser range finder with non-cooperative target.更多还原