Search

A study on temperature stabilization effect of the immersion liquid in a 3-6 GHz microwave tomography (MT) system for medical diagnosis is presented. The designed temperature control device unit is applied in the MT system for the analysis of the temperature impact. This control unit with an advanced control method is required to precisely maintain the temperature of the immersion liquid for obtaining stable measurement data. If the temperature of the liquid is maintained ideally, the peak to peak deviation of the measured amplitude and phase are very small within approximately 0.18 dB and 1.3 degree over the entire frequency range. The temperature variation of the liquid is a key factor for high spatial resolution to detect small tumors. The detailed results are presented and discussed. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:461–464, 2016

This paper presents an experimental measurement system for 3?6 GHz microwave tomography (MT) of the breast. The measurement system is constructed as a minimal test bed to verify key components such as the sensing antennas, radio frequency (RF) transceiver, sensing mechanism, and image reconstruction method for our advanced MT system detecting breast cancer at an early stage. The test bed has eight RF channels operating at 3 to 6 GHz for high spatial resolution and a two-axis scanning mechanism for three-dimensional measurement. The measurement results from the test bed are shown and discussed.

This article presents the image reconstruction results of measurement data from a preliminary test using the first-developed precision microwave tomography (MT) system operating at 3–6 GHz for medical diagnosis. A simple phantom is used in the MT system to verify the data validation. The measurement dataset has very different patterns owing to the significant contrast of dielectric properties according to the existence of a phantom in the sensing area of the illumination tank at microwave frequencies. Thus, it is possible to obtain the image reconstruction from this measurement data. The detailed results are presented and discussed. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2445–2448, 2015

A microwave (MW) focusing technique for non-invasive thermal therapy is presented. The proposed technique provides a thermal focusing at localized tissues as a cancer tissue and a deep tissue for muscular disorder treatment. We employed a time reversal technique for the targeted MW focusing and computational solvers for electromagnetic and thermal analysis are developed. To verify the proposed technique, we applied to an anatomically electromagnetic model based on magnetic resonance images. This work is a computational study to predict performances of the MW focusing system in our future work.

This paper presents a study of the microwave energy localization for pathologic treatment of the knee in human tissue. For the computational study, we have developed the finite difference time domain (FDTD) electromagnetic (EM) solver and FDTD thermal solver. The simulation test using these solver was performed for a 2D knee model with the tumor at 915 MHz. The time reversal (TR) algorithm was proposed the effective beam focusing at the target position. The detailed results are presented and discussed.

In this paper, a transmission array of a focused microwave thermotherapy system is introduced for those with diseases of the leg. A microwave time reversal analysis is introduced to understand microwave focusing. The transmitter circuit of a transmission array is evaluated by measuring the phase control and the magnitude control at the array output port. The results are satisfied to focus fields at a target point.

Compact printed ultrawideband (UWB) antennas with triple band-notched characteristic are proposed. The designed antennas consist of a rectangular shaped patch, complementary meander line split ring resonators (CMLSRRs), and a spiral resonator are inserted in the radiation patch, feed line, and ground plane aimed at WiMAX band, WLAN 5 GHz, and ITU 8 GHz. Therefore, techniques of their antennas can be solved the interference between UWB systems and other wireless systems. All of antennas achieved a wide bandwidth of UWB frequency range for VSWR less than 2, except for triple notched-bands. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2265–2269, 2013

We propose a novel configuration of a triple band-notched ultra-wideband (UWB) antenna. The designed structure is based on an elliptical monopole antenna combined with a complementary split ring resonator (CSRR) structure and a spiral resonator. The spiral resonator can achieve the dual-band notched performance at WiMAX band and ITU 8 GHz by adjusting the length and width of a spiral line. Besides, the CSRR can obtain the notched band at WLAN 5 GHz by changing the radius of a ring slot. The designed antenna shows that a VSWR of less than 2 was satisfied with a resonant frequency in the range of 1.34–11.4 GHz with a 78.96%, except for triple notched bands. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:4–6, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27275