A New Interpretation to Groszkowski’s Effect

This paper presents an alternative interpretation to Groszkowski’s effect, which states that the oscillation frequency of a harmonic oscillator is shifted due to the higher harmonic currents flowing into the LC tank. Groszkowki’s analysis starts by taking a strictly memoryless amplifier, to which he derives and expression for balance of reactive powers. Then he interprets the frequency shift as a matter of balance of reactive energy in the tank. Here we show that although a conductive amplifier is memoryless, it can still show phase shift at the fundamental tone. This is due to mixing of the fundamental and harmonics in the nonlinear i-v response of the amplifier. Now the new interpretation comes from the oscillation condition: if the amplifier shows phase shift, the tank needs to compensate it, and this causes the shift in the oscillation frequency. The mechanism is explained, analysed symbolically, and verified numerically.

Authors:
Nokandi Mostafa Jafari, Singh Sumit Pratap, Pärssinen Aarno, Rahkonen Timo

Publication type:
A4 Article in conference proceedings

Place of publication:
2019 IEEE Nordic Circuits and Systems Conference (NORCAS): NORCHIP and International Symposium of System-on-Chip (SoC) 29-30 Oct 2019 Helsinki, Finland

Keywords:
AM-PM, Frequency pulling, Groszkowski's effect, Nonlinear system, Oscillator

Published:
21 November 2019

Full citation:
M. J. Nokandi, S. P. Singh, A. Pärssinen and T. Rahkonen, “A New Interpretation to Groszkowski’s Effect,” 2019 IEEE Nordic Circuits and Systems Conference (NORCAS): NORCHIP and International Symposium of System-on-Chip (SoC), Helsinki, Finland, 2019, pp. 1-4. doi: 10.1109/NORCHIP.2019.8906981

DOI:
https://doi.org/10.1109/NORCHIP.2019.8906981

Read the publication here:
http://urn.fi/urn:nbn:fi-fe202001233107