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Absence of nonlinear responses in cells and tissues exposed to RF energy at mobile phone frequencies using a doubly resonant cavity
Author(s) -
Kowalczuk Christine,
Yarwood Gemma,
Blackwell Roger,
Priestner Marisa,
Sienkiewicz Ze,
Bouffler Simon,
Ahmed Iftekhar,
AbdAlhameed Raed,
Excell Peter,
Hodzic Vildana,
Davis Christopher,
Gammon Robert,
Balzano Quirino
Publication year - 2010
Publication title -
bioelectromagnetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.435
H-Index - 81
eISSN - 1521-186X
pISSN - 0197-8462
DOI - 10.1002/bem.20597
Subject(s) - demodulation , harmonic , amplifier , physics , materials science , optoelectronics , electrical engineering , acoustics , cmos , channel (broadcasting) , engineering
A doubly resonant cavity was used to search for nonlinear radiofrequency (RF) energy conversion in a range of biological preparations, thereby testing the hypothesis that living tissue can demodulate RF carriers and generate baseband signals. The samples comprised high‐density cell suspensions (human lymphocytes and mouse bone marrow cells); adherent cells (IMR‐32 human neuroblastoma, G361 human melanoma, HF‐19 human fibroblasts, N2a murine neuroblastoma (differentiated and non‐differentiated) and Chinese hamster ovary (CHO) cells) and thin sections or slices of mouse tissues (brain, kidney, muscle, liver, spleen, testis, heart and diaphragm). Viable and non‐viable (heat killed or metabolically impaired) samples were tested. Over 500 cell and tissue samples were placed within the cavity, exposed to continuous wave (CW) fields at the resonant frequency ( f ) of the loaded cavity (near 883 MHz) using input powers of 0.1 or 1 mW, and monitored for second harmonic generation by inspection of the output at 2 f . Unwanted signals were minimised using low pass filters (≤1 GHz) at the input to, and high pass filters (≥1 GHz) at the output from, the cavity. A tuned low noise amplifier allowed detection of second harmonic signals above a noise floor as low as −169 dBm. No consistent second harmonic of the incident CW signals was detected. Therefore, these results do not support the hypothesis that living cells can demodulate RF energy, since second harmonic generation is the necessary and sufficient condition for demodulation. Bioelectromagnetics 31:556–565, 2010. © 2010 Wiley‐Liss, Inc.