[22a-P03-1~11] 6.6 Probe Microscopy

[22a-P03-2] Reduction of Noise Induced by Power Supply Lines Using Phase-Locked Loop

〇Masayuki Abe¹, Hayato Yamashita¹, Souma Jinno¹, Hiroshi Toki¹ (1.Osaka Univ.)

Keywords:scanning tunneling microscopy, power line noise, phase-locked loop

Experimental technique for reduction of noise in signal line that is caused by power lines is presented, which improves a signal-to-noise ratio without limiting the bandwidth of the measurement system. A sinusoidal wave and its harmonics that are synchronized with the frequency of the power lines used for canceling out the power supply noise induced in a signal line. To generate the synchronized signals, we have developed a noise compensation electronics consisting of a phase locked loop and operational amplifiers. The amplitude and phase of these signals are adjusted and added to the signal lines to reduce the power supply noise. We applied this method to experiments of scanning tunneling microscopy and succeeded in improving the image quality.