EMF Exposure Application Using the Chamber of a Coaxial Line for 433-MHz ISM Band

In this letter, a new electromagnetic field (EMF) exposure application adopting the chamber of a coaxial line at 433 MHz designed for eight Alzheimer’s transgenic mice. Its structure consists of three types of coaxial lines: the first is standard coaxial line (e.g., N-type) for RF signal input or dummy load termination; the second has a characteristic impedance of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$50~\Omega $</tex-math> </inline-formula> for mode-matching between both standard coaxial line and chamber; and the third is used for the EMF exposure chamber. The mode-matching coaxial line features its dielectric diameter comparable to that of the chamber coaxial line. The EMF exposure chamber based on the coaxial line has the advantages of the wide impedance bandwidth and no external EMF emissions. The measured return loss for the system with eight phantoms was demonstrated as 20.9 dB at 433 MHz with a wide bandwidth. The estimated SAR at the target region was achieved as 0.051 W/kg/W<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">inc</sub>.