Ultra-wideband Dielectric Resonator Antenna Research Articles

Location of Early Stage Tumor Detection using Microwave Imaging in the Breast Phantom.

Universally, the most predominant cause of female mortality is mainly due to breast cancer. Owing to numerous constraints in the existing imaging technique, researchers are trying out an alternative tool to detect the tumor before going to the miserable stage. This article presents a novel method to detect the mean value system for detecting the location of the tumor in different depths by shifting the antenna anywhere in the breast tissue. In addition, an algorithm to reconstruct the breast image, namely Delay-Multiply-and-Sum (DMAS) is followed to identify the tumor implanted in the breast tissue. The analysis shows that the maximum mean value occurs while the antenna moves very near to the tumor while the mean value reduces while the antenna shifts apart from the tumor location. The mean value in different locations is converted into a microwave image. The high intensity in the image exhibits the precise position of the tumor. This technique can identify the location of early-stage tumor of size 3mm. Multiple tumors of sizes 6mm and 7mm can identify at a depth of 12mm and 18mm in the homogeneous breast phantom. DMAS can provide better imaging results in the early stage tumor of size 3mm embedded in the breast phantom. Microwave imaging is an efficient technique to differentiate healthy and malignant tissue in the breast. Antenna plays a major role in identifying tumors in the breast in the early stage. Hence a high-performance Ultra Wideband Dielectric Resonator Antenna (DRA-UWB) is used to identify the tumor in the breast. An antenna is sketched in different locations of the breast phantom. On account of the hemispherical structure, the mean value of the reflected signal is high at the center than at the edge. Hence, the difference in mean value is calculated with and without breast phantom for identifying the tumor location. The overall efficiency of this technique can be improved by using a high-performance UWB antenna. The image of the breast is reformed by the DMAS beamforming algorithm.

A low cost and efficient breast cancer detection method with a staircase shaped ultrawide band dielectric resonator antenna using monostatic radar based microwave imaging technique

In this article, a staircase-shaped ultra-wide band dielectric resonator antenna (DRA) has been used as a sensor for the detection of breast tumor by monostatic radar-based microwave imaging (MRMWI). The proposed DRA has fractional bandwidth (BW) 98.5% and a high peak gain 5.98 dB along with dual polarization behaviour from 5.12 to 8.2 GHz and 11.02-13.8 GHz. In the MRMWI setup, DRA is placed over the breast phantom at a distance of 7 mm and provides a safe exposure of radiation (<1.6 W/Kg). For simulation, it rotates around the phantom at a fixed interval in elevation (0-180°) and azimuthal (0-360°) planes. It works as a radiate and receives the reflected signals towards and from the scanned area simultaneously. To validate the results, fabricated DRA is connected to a vector network analyzer and rotates (as done for simulation) around the artificial breast phantom. That is a replica of the human breast made from gelatin+sugar, Vaseline and wheat flour+water equivalent to skin, fat and tumor respectively. Afterward S11 responses are recorded in the presence and absence of tumor inside the phantom. A significant variation in recorded values leads to the detection of tumors that are processed further in beam-forming algorithms; delay and sum (DAS) and delay-multiply and sum (DMAS) to reform the 2-dimensional image of tumor in MATLAB.

An Ultra-wideband Dielectric Resonator Antenna for WSN based IoT Applications in Agriculture

Background: Agriculture sector is one of the prime and widely spread sectors. So to make it autonomous and increase its yield, we require a major technological improvement. The only solution to make advancement is with the use of wireless sensor networks. Internet of Things in this field is used to provide connectivity to all real-time sensors and to collect that data in computer-based systems without human involvement. Objective: IoT based system is used to monitor physical and environmental conditions of the agriculture field through a network of wireless sensor. Here, a novel ultra-wideband Dielectric Resonator antenna is designed that is used in Wi-Fi for transmission of data received from sensors. The antenna designed should be easy to fabricate and compact in size and should provide high data rates. The complete designed system should be reliable and cost effective one. Method: A proposed IoT based system monitors physical and environmental conditions using a wireless sensor network consisting of power supply, soil moisture sensor (FC-28), humidity sensor (LM-35), temperature sensor (HR-202), water level sensor, ARM 7 processor, Liquid Crystal Display (LCD), Relay, motor and Wi-Fi module that is installed at remote locations and connected to the main system comprises of a novel ultra-wideband Dielectric Resonator antenna. Results: The designed WSN based IoT system for agriculture application monitors temperature, humidity, soil moisture, and water level in the field. For Wi-Fi module implementation ultra-wideband inverted sigmoid shaped DRA is designed that provides an impedance bandwidth of 36.46 % at 6.226 GHz (5.51 - 7.78 GHz). The designed antenna provides a peak gain of 5.44 dB at a resonant frequency of 6.226 GHz. Conclusion: The proposed IoT based system is used to monitors physical and environmental conditions like soil moisture, humidity, temperature and water level and sends the data through Wi-Fi module comprising of an ultra-wideband Dielectric Resonator antenna. The designed antenna is compact and can be easily fabricated using printed circuit board technology. The complete system is cost-effective and can be easily implemented.

Monostatic Radar-Based Microwave Imaging of Breast Tumor Using an Ultra-wideband Dielectric Resonator Antenna (DRA) with a Sierpinski Fractal Defected Ground Structure

Monostatic Radar-Based Microwave Imaging of Breast Tumor Using an Ultra-wideband Dielectric Resonator Antenna (DRA) with a Sierpinski Fractal Defected Ground Structure

Design of Ultra-Wide Band Dielectric Resonator Antenna with Enhanced Bandwidth and Gain

Design of Ultra-Wide Band Dielectric Resonator Antenna with Enhanced Bandwidth and Gain

Ultra-Wideband Dielectric Resonator Antenna Design Based on Multilayer Form

In this paper, an ultra-wideband dielectric resonator antenna (DRA) is investigated. It basically covers the bandwidth from 6 GHz to 16 GHz and achieves a relative bandwidth of 90.9%. It is found that a wide bandwidth can be reached with a small DRA by adopting multilayer form. Thus, the dimension of the designed DRA element which is composed of nine-element phased-scanning linear array is as small as 6.9mm x 8.2mm x 11 mm. While the maximum stable zenith gain is 6.2dB, the lobe width is 3 dB. The operating frequency range of the antenna array is from 5.42GHz to 16.5GHz, achieving a 101.1% relative bandwidth. A large scanning angle of ±60° is realized within the operating frequency band, with good scanning pattern and cross polarization. To verify the design and simulation, a 1 × 9 DRA array is fabricated, and measurements are carried out.

A Frequency Reconfigurable Band-notched UWB Dielectric Resonator Antenna with a Wide-tuning Range for Cognitive Radio Systems

A new reconfigurable band-notched ultra-wideband (UWB) dielectric resonator antenna (DRA) has been designed and fabricated for cognitive radio (CR) applications. The UWB antenna design comprises a dielectric resonator as a radiation element, a ground plane, and a microstrip feed line. The frequency band’s rejection mechanism is achieved by cutting two slots and adding an L-shaped stub on the ground plane. The reconfigurable function is created by PIN diode switches to change the current distribution path on the ground plane. A preliminary model of the DRA was fabricated, and its efficiency was verified. The proposed antenna occupies an area of 40 × 40 × 7.3 mm. The simulated and measured results have demonstrated suitable radiation patterns attained by the proposed antenna, which operates within the UWB frequency range of 3–11 GHz. Moreover, the antenna has shown an ability by rejecting switchable bands to achieve the WiMAX (3.2–3.65 GHz), WLAN 5 GHz (4.8–6 GHz), and ITU 8 GHz (8–8.3 GHz). Also, this antenna can be operated as dual and triple band-notched antennas.

Pulse‐preserving characteristics and effective isotropically radiated power spectra of a new ultrawideband dielectric resonator antenna

A dielectric resonator antenna (DRA) with a full ground plane and an ultrawideband (UWB) operating bandwidth of 3.1–11.6 GHz is presented. Good return loss over a wide bandwidth is achieved, while the full ground plane directs most of the radiation into the upper hemisphere, significantly reducing undesirable radiation to the lower hemisphere. The measured results confirm a 10-dB return-loss bandwidth of 115%. Time-domain characteristics and effective isotropically radiated power (EIRP) spectra of the antenna are investigated for several types of UWB input pulses. The correlations between the input pulses and the radiated pulses in many directions were found to be excellent when the antenna is excited by a linearly chirped Gaussian pulse or a fifth-order Gaussian pulse. Nevertheless, EIRP spectrum calculations indicate that none of those pulses efficiently fill the Federal Communication Commission UWB mask when applied to this DRA. Hence, a third-order Rayleigh pulse is introduced and tuned to make efficient use of the allowed spectrum limits. Further improvement of pulse performance is investigated by varying antenna design parameters. This DRA is suitable for both impulse radio UWB systems and carrier-based UWB systems.

A new simple compact ultra-wideband dielectric resonator antenna with enhanced bandwidth and improved radiation pattern

A new simple compact ultra-wideband (UWB) dielectric resonator antenna is presented. The antenna consists of a modified stepped microstrip-fed monopole printed antenna loaded with a rectangular dielectric resonator, truncated ground plane, and a parasitic strip underneath the dielectric resonator (DR). Using an optimized truncated ground plane and a combination of stepped feed line with DR an ultra-wide impedance bandwidth of 153% for (∣S11∣ ≤ −10 dB), covering the frequency range of (3.7–28 GHz) is achieved. The added parasitic strip can improve the radiation pattern, especially at high frequencies. The proposed antenna covers almost the entire UWB (3.1–10.6 GHz), Ku (12.4–18 GHz), and K (18–26.6 GHz) frequency bands. Also this antenna has an omnidirectional and stable radiation pattern over the whole operating frequency range and a compact size of (15 × 20 × 5.8 mm3) that make it suitable for wideband wireless system applications. This structure is light weight and can be easily fabricated. A prototype is built and measured. The simulated and measured results are in good agreement.

Hybrid ultrawideband dielectric resonator antenna and band-notched designs

A novel dielectric resonator antenna (DRA) is proposed for ultrawideband (UWB) applications, where a simple rectangular dielectric resonator is excited by a bevel-shaped patch connected to a coplanar waveguide (CPW) feeding line. It is found that the bandwidth of the resonant modes can be expanded by using a CPW-fed ground and bevel-shaped patch, and thus a UWB performance can be achieved. Experimental and numerical results were carried out, showing a good agreement. The measured results demonstrate that the proposed DRA achieves an impedance bandwidth more than 3:1, covering the frequency range from 3.1 to 10.6 GHz, which is suitable for UWB applications. Furthermore, to minimise the potential interferences between the UWB system and narrowband systems, such as world interpretability for microwave access and WLAN, UWB DRAs with single band-notched and dual band-notched characteristics were designed, fabricated and measured. The measurement results show good performances in terms of VSWR, antenna gain and radiation pattern. With these features, the proposed antennas are expected to be good candidates in various UWB systems.

Ultrawideband Dielectric Resonator Antenna for DVB-H and GSM Applications

This letter presents a novel design of compact dielectric resonator antenna (DRA) that is dedicated to ultrawideband applications such as digital video broadcasting-handheld (DVB-H). The dimensions of the radiation element are lambda <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> /7 times lambda <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> /13 times lambda <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> /28 at 466 MHz. A miniaturization technique has been used in order to reduce the antenna size, and a parametric analysis of the antenna is performed. The measured results agree well with the simulated ones. The proposed antenna offers a bandwidth of 70% around 700 MHz for -8 dB impedance matching bandwidth definition and covers the Ultra High Frequency (UHF) IV, V and Global System for Mobile communications (GSM) bands.