Miniature microwave antennas for electric field sensing under hyperthermia conditions

Hyperthermia applicators are generally characterized by determining the pattern of the SAR (specific absorption rate) in tissue-simulating phantoms. A Narda model 15 miniature isotropic implantable electric field probe was used for the SAR determination. All measurements were made at a frequency of 915 MHz, which is that generally used for interstitial applicators. Also described are measurements during hyperthermia to facilitate optimization of the treatment and new designs for submillimeter isotropic electric field probes. The novel probe designs are described in which the rectified outputs from the three dipoles are combined at locations close to the dipoles so that only one pair of high-resistance leads is required.<>