Reliable study of time- and frequency-domain EMI-induced noise in Wien bridge oscillator

Electromagnetic interference (EMI) has an adverse effect upon the performance of electronic circuit communication systems. This study derives a series of equations to analyze the effects of the EMI induced in a conducting wire on the noise spectrum produced in a Wien bridge oscillator (WBO). The equations are verified experimentally. The results indicate that the effect of the EMI on the WBO depends on the interference power, the interference frequency, the induced power, the output resistance of the WBO circuit, and the parasitic capacitance. Moreover, it is shown that the harmonic noise increases with an increasing interference amplitude or frequency.