Effect of tumor tissue on implant antenna performance at 2.38 GHz

This paper demonstrates the detrimental effect a tumor can have on the performance of an antenna implanted in close proximity to said tumor. It was shown through simulation and measurement that a high water content tumor in the immediacy of an antenna implanted in a low water content tissue, such as breast tissue, will cause resonant frequency and bandwidth changes alongside a reduction in radiation efficiency. These effects were shown to increase as the tumor increased in volume with a maximum resonant frequency shift of 3.2% and a reduction in measured radiation efficiency relative to the diameter of the tumor of 0.1 dB/mm. Antennas with dual resonance are shown to mitigate resonant frequency variation effects.