New Tools for Fast and Sensitive Noise Measurements

conference paper

English

Instrumentation to improve the power spectrum density (PSD) and the time sequential low frequency noise measurements, a high sensitive premplifier and a data acquisition unit are designed as well as a programmable power battery souce. The preamplifier has the JFET input 8 in parallel resulting in the input noise equivalent power of -186 dBV^{2}/Hz. The data acquisition system consists of a low pass filter and a RAM, which transfer the data to the connected PC. The FFT or other signal processing is done within the PC, enabling to supply the DUT required DC power through the program. This measuring system works satifyingly well at room temperature where the DUT and the power source could be put into a magnetic shielding box to reject spurious line noises. In the case to put the DUT in a cryostat to measure the temperature dependence of noise properties, however, the shielding of the DUT from the power line becomes a serious problem. Especially in order to use a compressor cooling system, spurious noises come in to the measuring system through the power lines of the compressor. In such a case the pramplifier must be put as close as possible to the DUT, and the power line to the compressor must be disconnected from the system.

noise, nonlinearity, nanoscale devices

ŠIKULA, J., TACANO, M., HASHIGUCHI, S., YOKOKURA, S.

2003

1. 1. 2003

CNRL

Brno

51

51

1