An ultra‐wideband compact design for hyperthermia: Open ridged‐waveguide antenna

Abstract

Antennas are the building block of radiative hyperthermia (HT) applicators. This study proposes a compact UWB antenna specifically tailored to meet the requirements for deep HT array applicators. The proposed Open Ridged‐Waveguide (ORWG) antenna, which is an adaptation of a double‐ridged horn antenna, operates over the frequency band of 400–800 MHz. It was experimentally assessed as a single element. The quality metrics considered were reflection coefficient, penetration depth, effective field size (EFS), and mutual coupling. The design shows a 75.5% fractional bandwidth with a reflection coefficient measured to be below −10 dB from 367 up to 820 MHz. The EFS is greater than the physical dimensions of the 3‐by‐4 cm aperture. The mutual coupling between two adjacent elements in the array, measured in a flat phantom arrangement, is lower than −30 dB throughout the entire band. The antenna's performance was further tested in two deep HT scenarios in order to assess the mutual coupling and focussing abilities while in the array configuration. To this end, phased array applicators consisting of 10 and 16 ORWG antennas were simulated in CST, and the results are presented for a homogeneous cylindrical muscle phantom and a realistic patient model, respectively. The good agreement between the simulated and measured results suggests that the antenna can be successfully used for HT.

Micro-Opening Ridged Waveguide Tumor Hyperthermia Antenna Combined with Microwave-Sensitive MOF Material for Tumor Microwave Hyperthermia Therapy

“…Simple waveguide antennas exhibit a poor near-field focusing effect. To improve the radiation performance of the antenna, double ridges are added to the waveguide, so that the electromagnetic field is concentrated between the two ridges. , To ensure impedance matching, the outer conductor of the coaxial line is connected to the edge of the ridged waveguide, and the inner conductor is extended to the opposite ridge to achieve matching, forming a monopole radiator. In this experiment, an open double-ridged ladder-fed small waveguide antenna with a working frequency of 915 MHz was designed, as shown in Figure a–e.…”

A sub 1 GHz ultra miniaturized folded dipole patch antenna for biomedical applications

“…An open ridged-waveguide antenna (ORWA) was proposed to achieve ultrawideband in Ref. 40 operating between 400 and 800 MHz. The EFS of the antenna exceeds its dimensions (30 mm 40 mm) for the mentioned frequency band with input power between 7 and 25 W while SAR of 56 to 29 W/kg was achieved suitable for Hyperthermia.…”