Auto-phase calibration loop of a transmission array for focused microwave thermotherapy

In this paper, we introduce an automatic phase calibration loop circuit for a focused microwave thermotherapy system for those with diseases of the leg. An extended time reversal method is also introduced. The loop circuit is evaluated by measuring the phase errors at the array antenna feeding port. These measurements are compared to those without a loop. The results show that the overall phase errors are reduced enough to focus fields at a target point.

I. Introduction

Microwave thermotherapy can treat carcinoma cells in the human body, and the non-invasive, deep and local treatment offered by this type of therapy is advantageous. Focused microwave thermotherapy was introduced as a treatment for breast cancer by Alan J. Fenn [1], and its application can now be extended to diseases of the leg, such as osteosarcoma. An advanced and focused microwave thermotherapy system for cases involving diseases of the leg is designed in this paper. Sections of the human leg are relatively complicated compared to breast cases. Many array elements with antennas, 16 for this application, are required, and each array has its own power transmitter for which the phase and magnitude are controlled. This concept is shown in Fig. 1. Fig. 1.

Focused microwave thermothrerapy system for human legs