Research Output

Calibration model for detection of potential demodulating behaviour in biological media exposed to RF energy

  Potential demodulating ability in biological tissue exposed to radio-frequency (RF) signals intrinsically requires an unsymmetrical diode-like non-linear response in tissue samples. This may be investigated by observing possible generation of the second harmonic in a cavity resonator designed to have fundamental and second harmonic resonant frequencies with collocated antinodes. Such a response would be of interest as being a mechanism that could enable demodulation of information-carrying waveforms having modulating frequencies in ranges that could interfere with cellular processes. Previous studies have developed an experimental system to test for such responses: the present study reports a circuit model to facilitate calibration of any non-linear RF energy conversion occurring within a test-piece inside the cavity. The method is validated computationally and experimentally using a well-characterised non-linear device. The proposed model demonstrates that the sensitivity of the measurement equipment plays a vital role in deciding the required input power to detect any second harmonic signal, which is expected to be very weak. The model developed here provides a lookup table giving the level of the second harmonic signal in the detector as a function of the input power applied in a measurement. Experimental results are in good agreement with the simulated results.

  • Type:


  • Date:

    01 October 2017

  • Publication Status:


  • Publisher

    Institution of Engineering and Technology (IET)

  • DOI:


  • Library of Congress:

    TK Electrical engineering. Electronics Nuclear engineering

  • Dewey Decimal Classification:

    621.38 Electronics & Communications engineering

  • Funders:

    Historic Funder (pre-Worktribe)


See, C. H., Abd-Alhameed, R. A., Ghani, A., Ali, N. T., Excell, P. S., McEwan, N. J., & Balzano, Q. (2017). Calibration model for detection of potential demodulating behaviour in biological media exposed to RF energy. IET Science, Measurements and Technology, 11(7), 900-906.



cavity resonators; biological tissues; table lookup; calibration; medical signal detection; harmonic generation; biological techniques; demodulation

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