A Broadband Complex Permittivity Probe Using Stepped Coaxial Line

Samsuzzaman

et al. 2018

Sensors

Microwave breast imaging has been reported as having the most potential to become an alternative or additional tool to the existing X-ray mammography technique for detecting breast tumors. Microwave antenna sensor performance plays a significant role in microwave imaging system applications because the image quality is mostly affected by the microwave antenna sensor array properties like the number of antenna sensors in the array and the size of the antenna sensors. In this paper, a new system for successful early detection of a breast tumor using a balanced slotted antipodal Vivaldi Antenna (BSAVA) sensor is presented. The designed antenna sensor has an overall dimension of 0.401λ × 0.401λ × 0.016λ at the first resonant frequency and operates between 3.01 to 11 GHz under 10 dB. The radiating fins are modified by etching three slots on both fins which increases the operating bandwidth, directionality of radiation pattern, gain and efficiency. The antenna sensor performance of both the frequency domain and time domain scenarios and high-fidelity factor with NFD is also investigated. The antenna sensor can send and receive short electromagnetic pulses in the near field with low loss, little distortion and highly directionality. A realistic homogenous breast phantom is fabricated, and a breast phantom measurement system is developed where a two antennas sensor is placed on the breast model rotated by a mechanical scanner. The tumor response was investigated by analyzing the backscattering signals and successful image construction proves that the proposed microwave antenna sensor can be a suitable candidate for a high-resolution microwave breast imaging system.

Section: Homogenous Phantom Development and Measurementmentioning

confidence: 99%

A Homogeneous Breast Phantom Measurement System with an Improved Modified Microwave Imaging Antenna Sensor

Samsuzzaman

et al. 2018

Sensors

“…In the first model, a coaxial probe terminated in layered dielectric materials of finite thickness. (12)(13)(14)(15) Here, the sample of the dielectric material is backed by either free space or a finite metal sheet as seen in Fig. 1.…”

Section: Overview Of Dielectric Constant Characterization Techniquesmentioning

confidence: 99%

A Simple Resonance Method to Investigate Dielectric Constant of Low Loss Substrates for Smart Clothing

Azeez¹,

Chen²,

Wu³

et al. 2018

Sensors and Materials

Wireless body area networks (WBANs), because of their widespread applications in health care and industrial development, have an important share of the recent advancements of the Internet of things (IoT). The term "wireless" is a key element of any new user-friendly wearable technological devices in health monitoring. This concept is reinforced by the utilization of wearable antennas and ultimately leads to the integration of technique and clothes; therefore the concept of smart clothing has been introduced. Wearable antennas are different because they are planar, durable, and user friendly. In this regard, the most prevalent type of antenna that has variety of forms and patterns is the microstrip antenna. Planar antennas in general need flexible and thin substrates that enable them to be mounted on textiles. Consequently, materials such as felt, polyester, and denim are excellent candidates for the development of wearable antennas. The materials are known for having less loss in comparison to conventional substrates. However, the electromagnetic properties of such regular fabrics are not well known and are none of fabric manufacturer's concern. Therefore, a very simple technique to characterize the electromagnetic properties of sample fabrics as antenna substrates for wireless body communications in this study is proposed. Because microstrip antennas are less dependent on the imaginary part of the complex dielectric constant of the substrates, the unique method presented in this paper helps researchers determine the real part of the dielectric permittivity straightforwardly and without advanced knowledge of the substrate. The method can be considered as an example of applications of antennas to characterizing electromagnetic properties of materials. The structure of the method involves square-patch antennas that are directly fed at the center of the patch. The lowest resonance mode of the patch antenna is the key parameter in the process.Step-by-step procedures and materials used in this study to develop the method are explained and discussed. The stability and accuracy of the method is evaluated using simulations and measurements. 596

“…[26]- [27]- [28] Distilled water is usually used to be the material standard because of its known complex permittivity. [29] The Roberts and von Hippel method requires measurement to determine the standing wave-ratios (SWR's) in the line with and without the sample inserted. From the shift of the standing-wave node and changes in node widths related to SWR's, sample length, and waveguide dimensions, etc.…”

Section: Sample Preparationmentioning

confidence: 99%

Comparison of Dielectric Constant & Loss Factor for Preliminary, Oven Dried and Saturated Grains Using Ku Band Microwave Frequency

2017

IJSR

The paper speaks to the investigation of dielectric constants alongside their loss factor for different sorts of grains which characterize their reactions against electromagnetic energy at various microwave frequencies by absorbing, radiates, reflect, and disperse a segment of electromagnetic energy. Estimation of dielectric consistent and loss factor have made for different specimens of grains, for example, Rice, Wheat, Split Red Gram (Arhar), Bengal Gram (Chana), Green Gram (Moong)for three unique states as preliminary, oven dried and saturated at various gravimetric moisture content in scope of CJ Band at two different frequency values (5.30 and 6.60 GHz) and furthermore in the scope of X Band at frequency of 10.65 GHz by utilizing waveguide cell (short-circuited lines or double minima or two point) technique. The general lab measurements are similarly critical in recognizing the grains and relatively increase the characterized crop productivity by using microwave remote sensing applications. The analytical study of various grains and pulses at microwave frequencies may give data about the vegetation field and furthermore distinguishes their behavioral properties. The examination of a capacity of cereals and pulses to absorbing emits, disperse, and reflect a part of an electromagnetic field is found by determining dielectric constant and fluctuation with the real factors. Accordingly, estimation of dielectric steady are made for different specimens of grains, for example, Rice, Wheat, Bengal Gram (Chana), Green Gram (Moong), Split Red Gram (Arhar) for three particular stages named as preliminary, oven dried and saturated at various gravimetric moisture content for Ku Band at 12.8 GHz. By utilizing waveguide cell (short-circuited lines or double minima) technique estimations have been made, includes focusing of microwaves over the specimen in a rectangular waveguide cell and fundamental standards engaged with it. The general research center measurements are assuming indispensable part to identify the grains and enhancing crop yield by utilizing microwave remote detecting applications. This paper introduces the data with respect to the impact on the essential variables influencing the dielectric properties of the agricultural products, and for detecting the quality characteristics of the agricultural products.