Ultra-wideband Microwave Imaging System Research Articles

An Ultra-Wide Band MIMO Antenna System with Enhanced Isolation for Microwave Imaging Applications.

This paper introduces a novel two-port ultra-wideband (UWB) multiple-input multiple-output (MIMO) antenna system with enhanced isolation characteristics. The antenna, designed on a thin 0.787 mm RO5880 substrate, achieves a compact form factor of 52 × 26 mm2 and offers a wide bandwidth of 9.2 GHz (2.3 GHz to 11.5 GHz) while meeting the VSWR 2:1 criterion. Notably, the proposed antenna demonstrates an impressive increase in isolation, up to 16 dB, through the integration of a shared radiator with small rectangular slots, effectively reducing interference and improving overall performance. Furthermore, a comprehensive analysis of additional MIMO performance parameters, including the envelope correlation coefficient (ECC) and diversity gain, confirms their satisfactory limits, validating the potential of the proposed UWB-MIMO antenna for various UWB applications. The time domain analysis of the UWB antenna is also analyzed, and results are found to be within satisfactory limits. Simulation and measurement results further support the practicality and effectiveness of the antenna design, highlighting its compact size, wide bandwidth, and enhanced isolation characteristics, positioning it as a promising solution for advanced UWB microwave imaging systems.

Development of an ultra-wideband, stable and high-directive monopole disc antenna for radar-based microwave imaging of breast cancer

ABSTRACTRadar-based ultra-wideband (UWB) microwave imaging (MI) system has recently attracted considerable attention for detection of breast cancer at early stage. A key component of the system is the sensor (antenna) that is used to radiate and receive the UWB pulses. In this study, a compact-size, UWB, directive, and microstrip-fed planar circular disc monopole antenna (PCDMA) with modified L-shaped ground plane for the radar-based UWB MI system is developed. Analysis and the performance optimization of the proposed antenna are performed by HFSS software. In the development process of the antenna design, some modifications such as adjusting feed point, adding parasitic element, slot, notches are made on the conventional PCDMA to improve the bandwidth, directivity and half-power beamwidth (HPBW) of the antenna. After obtaining the optimum parameters, the proposed antenna is fabricated and then tested by using Vector Network Analyser. Impedance bandwidth of the designed antenna covers the broad frequency range of 3–10 GHz (108%) for Return Loss < –10 dB. The good stability of the directional radiation patterns is obtained in the 3–10 GHz. The direction of the maximum radiation moves from 32° to 54° and HPBW decreases from 56° to 30° through the frequency band. The directivity changes between 6.2 and 9.4 dB in the 3–10 GHz. Results confirm that the proposed antenna is suitable for using in radar-based UWB MI of the breast cancer.

A high performance UWB antenna design for microwave imaging system

ABSTRACTIn this paper, a new design of ultra‐wideband (UWB) antenna is reported for a microwave imaging system aimed to cover the UWB bandwidth from 3.1 to 10.6 GHz. The structure has a very simple Hibiscus petal pattern patch with tapered microstrip fed a line and partial trapezoid ground plane. The gap between the Hibiscus petal pattern patch and partial ground of the antenna are optimized to achieve wide impedance bandwidth. Results show that the antenna has a fractional bandwidth of about 120% from 3.04 to 11 GHz with S11 &lt; −10 dB with stable omnidirectional radiation pattern. The average gain of proposed prototype is 5.1 dBi and the radiation efficiency is about 85% on an average over the bandwidth. The fidelity factor for face to face is 0.8469 and for side by side is 0.9232 which represent the lower distortion of signal. The characteristics of proposed antenna are successfully simulated, prototyped and measured. Fairly good agreements between the simulations and measurements have been achieved. The reported antenna has a better impedance match and mutual coupling that provides a practical approach to realize the antenna for the UWB microwave imaging system. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:1824–1831, 2016

An Efficient Image Reconstruction Method for Breast Cancer Detection Using an Ultra-Wideband Microwave Imaging System

ABSTRACTMicrowave breast imaging uses backscattered radar signals to identify cancerous tissue within the breast. It is a non-invasive technique and uses non-ionizing radiation; it is currently a potential alternative for classical techniques. This article presents an efficient image reconstruction method for breast cancer detection using an ultra-wideband microwave imaging system. This method consists of applying the improved version of the delay-and-sum algorithm and post-processing the resultant images. For that, we have used a numerical 3D breast phantom in CST software simulation tool (CST Inc., 2014). The breast was illuminated with ultra-wideband (UWB) pulse from a number of antenna locations, and then collected reflections were synthetically focused to create an energy map of the breast. A new algorithm is also introduced that post-processes the resulting images obtained through different configurations of acquisition point positions. This post-process allows a much clearer image to be obtained with less interference. In the constructed and post-processed image, the presence and location of single and double breast cancer tumors of 2 mm in diameter can clearly be identified.

Ultra-wide band microwave image reconstruction for early breast cancer detection by norm constrained capon beamforming

In this paper, an efficient and robust image reconstruction algorithm for breast cancer detection by ultra-wide band microwave imaging system is presented. To test the efficacy of this approach, a three-dimensional model of the breast organisms is numerically carried out by the FDTD method. The PML absorption boundary condition is developed in the computer system. The norm constrained capon beamforming (NCCB) algorithm is employed to create the weighting vector for the image reconstruction. The tumor with the size of 3 mm in diameter detected successfully in the reconstructed image demonstrates the robustness of the beamforming algorithm. The study verifies the feasibility of detecting the small breast tumors by using the NCCB imaging algorithm.

EXPERIMENTAL ASSESSMENT OF MICROWAVE DIAGNOSTIC TOOL FOR ULTRA-WIDEBAND BREAST CANCER DETECTION

An ultra-wideband microwave imaging system that employs a heterogeneous breast phantom and covers the ultra-wideband (UWB) frequency range (3.1 GHz to 10.6 GHz) is presented. The platform scanning system allows monostatic and bistatic mode of operation. In this work, developed heterogeneous phantoms are used to mimic the realistic breast tissues. A utilized tapered slot antenna array allows for a high resolution hemispherical scan, achieved by rotating the imaged object on a turntable. Full design details of the scanning system and the utilized post-processing algorithm are explained. To validate the reliability of the presented system, the results of several imaging cases, including the challenging low dielectric contrast case, are presented.

Design of Ultra-Wideband MIMO Antenna for Breast Tumor Detection

A MIMO antenna composed by microstrip line-fed circular slot antenna is proposed. This antenna is used in ultra-wideband microwave imaging systems aimed for early breast cancer detection. The antenna is designed to operate across the ultra-wideband frequency band in the air. The mutual coupling between the antenna elements has been investigated to be low enough for MIMO medical imaging applications. Both the simulation and measurement results are shown to illustrate the performances of the proposed antenna.

Heterogeneous breast phantom for ultra wideband microwave imaging

AbstractWith the growing interest in the microwave imaging for early breast cancer detection, there is a need to develop an advance artificial breast phantom to emulate the interactions of electromagnetic waves with biological tissues. In this article, details of a realistically shaped heterogeneous breast phantom manufactured for the use in an ultra wideband microwave imaging system are presented. The developed phantom has electrical characteristics which are in good agreement with those of real breasts. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26046

Design of tapered slot Vivaldi antenna for UWB breast cancer detection

AbstractA tapered slot antenna to be used in ultra wideband microwave imaging systems aimed for early breast cancer detection is presented. A synthetic array is designed to operate across the ultra wideband frequency band in the air. The mutual coupling effects between the antennas have been investigated to verify the feasibility of the antenna for medical imaging applications. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:639–643, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25770

Compact directional antenna for ultra wideband microwave imaging system

AbstractA planar antenna of tapered slot configuration for use in ultra wideband microwave imaging systems aimed for early breast cancer detection is presented. It is designed to operate across the ultra wideband frequency (3.1–10.6 GHz) in a liquid of a high dielectric constant that matches the electric properties of average breast tissues. It has a very compact size with overall dimensions of 0.9 cm × 1 cm. The antenna's ultra wideband performance even when it is close to the breast tissues and its distortionless response in the time domain make it suitable for the microwave imaging systems utilizing a short‐pulse radar technique. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2898–2901, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24764

An Ultra Wideband Microwave Imaging System for Breast Cancer Detection

An experimental study concerning Ultra Wideband (UWB) Microwave Radar for breast cancer detection is described. A simple phantom, consisting of a cylindrical plastic container with a low dielectric constant material imitating fatty tissues and a high dielectric constant object emulating turnout, is scanned with a tapered slot antenna operating between 3.1 to 10.6 GHz. A successful detection of a target is accomplished by a visual inspection of a two-dimensional image of the scanned phantom.