Design of Miniaturized External Dual-Band Microstrip Circular Patch Antenna for Microwave Hyperthermia

Abstract

This paper designs a miniaturized in vitro dual-band microstrip circular patch antenna for microwave thermal therapy, with antenna resonant frequencies of 915 MHz and 2450 MHz and a circular patch size of 7 mm radius. It is capable of achieving a reflection coefficient of –25.51 dB at 915 MHz with a bandwidth of 30 MHz (S11 < –10dB) and –36.84 dB at 2450 MHz with a bandwidth of 270 MHz (S11 < –10 dB). The antenna can form an energy focusing area in the human surface tissue below the circular patch, and the focal point position is the same at both frequencies. After simulation, it is verified that 915 MHz can achieve a larger radiation area than 2450 MH with the same SAR field penetration depth. It is possible to select the appropriate frequency for the size of superficial tumor to achieve the effect of precise tumor treatment.