Gain enhancement of the ultra-wideband tapered slot antenna using broadband gradient refractive index metamaterial

2017 ◽  
Vol 28 (2) ◽  
pp. e21191 ◽  
Author(s):  
Rahul Singha ◽  
D. Vakula
Keyword(s):  
Refractive Index ◽  
Ultra Wideband ◽  
Slot Antenna ◽  
Gain Enhancement ◽  
Gradient Refractive Index

scholarly journals Low Side Lobe Tapered Slot Antenna with High Gain Using Gradient Refractive Index Metamaterial for Ultra Wideband Application

2017 ◽  
Vol 6 (4) ◽  
pp. 63-69 ◽  
Author(s):  
R. Singha ◽  
D. Vakula
Keyword(s):  
Refractive Index ◽  
Beam Width ◽  
Parallel Line ◽  
Side Lobe ◽  
High Gain ◽  
Ultra Wideband ◽  
Slot Antenna ◽  
Side Lobe Level ◽  
Beam Focusing ◽  
Gradient Refractive Index

A broadband gradient refractive index (GRIN) metamaterial is used to improve the gain of the tapered slot antenna. The proposed metamaterial is capable of reducing the side lobe level of the antenna. The gradient refractive index (GRIN) metamaterial is constructed by using non-resonant parallel-line unit cells with different refractive index. Due to the non-resonant structure, the proposed unit cell exhibits low loss and large frequency bandwidth. The metamaterial, whose effective refractive index is lower than that of the substrate on which the antenna is printed. Therefore, the proposed metamaterial is act as a regular lens in beam focusing. The GRIN metamaterial is integrated in front of the antenna which has the capability to manipulate electromagnetic wave accurately. The measurement results indicate that the reflection coefficient of the antenna is below -10 dB over the frequency band from 3 to 11 GHz. The radiation pattern of the antenna shows the beam width becomes narrow and directive with low side lobe level. The peak gain is increased by 2.1 dB at 9.5 GHz.

Ultrawideband Antipodal Tapered Slot Antenna With Gradient Refractive Index Metamaterial Lens

2019 ◽  
Vol 18 (12) ◽  
pp. 2741-2745 ◽  
Author(s):  
Zhengwei Yang ◽  
Linyan Guo ◽  
Changli Yao ◽  
Qisheng Zhang ◽  
Ziyu Xu ◽  
...  
Keyword(s):  
Refractive Index ◽  
Slot Antenna ◽  
Gradient Refractive Index

scholarly journals Gain Enhancement of Double-Slot Vivaldi Antenna using Corrugated Edges and Semicircle Director for Microwave Imaging Application

2021 ◽  
Vol 21 (2) ◽  
pp. 85
Author(s):  
Findi Nur Witriani ◽  
Yahya Syukri Amrullah ◽  
Fajri Darwis ◽  
Taufiqqurrachman Taufiqqurrachman ◽  
Yusuf Nur Wijayanto ◽  
...  
Keyword(s):  
Medical Profession ◽  
High Gain ◽  
Microwave Imaging ◽  
Ultra Wideband ◽  
Slot Antenna ◽  
Gain Enhancement ◽  
Imaging Application ◽  
Vivaldi Antenna ◽  
Compact Design ◽  
Slot Structure

Microwave imaging, such as images for radiological inspection in the medical profession, is one of the applications utilized in ultra-wideband (UWB) frequency ranges. The Vivaldi antenna is one of the most popular antennas for this purpose. The antenna is utilized because of its simple, lightweight, and compact design, as well as its excellent efficiency and gain capabilities. In this work, we present a high-gain Vivaldi antenna for microwave imaging applications. The proposed Vivaldi antenna is designed using a double-slot structure method with the addition of corrugated edges and a semicircle director aimed at improving the gain. The antenna is designed to operate at frequencies ranging from 3.1 to 10.6 GHz. Based on the modeling findings, the suggested antenna attain a bandwidth of 7.5 GHz with operating frequencies from 3.1 GHz to 10.6 GHz for a VSWR of less than two. In comparison to a typical single slot antenna, the suggested antenna provides a substantial boost in gain performance. The increase in gain is proportional to the frequency of operation. The constructed antenna has a lower bandwidth than the simulated one, with operating frequencies of 3.5 GHz – 3.75 GHz and 4.25 – 10.89 GHz, respectively, and useable bandwidths of 250 MHz and 6.64 GHz. All these results suggest that the antenna is suitable for microwave imaging applications.

scholarly journals Wideband-Narrowband Switchable Tapered Slot Antenna for Breast Cancer Diagnosis and Treatment

2021 ◽  
Vol 11 (8) ◽  
pp. 3606
Author(s):  
Seonho Lim ◽  
Young Joong Yoon
Keyword(s):  
Breast Cancer ◽  
Coupling Effect ◽  
Breast Cancer Diagnosis ◽  
Microwave Imaging ◽  
Ultra Wideband ◽  
Slot Antenna ◽  
Pin Diode ◽  
Time Frequency ◽  
Switching Mode ◽  
Meander Line

In this paper, a wideband-narrowband switchable tapered slot antenna (TSA) with a compact meander line resonator for an integrated microwave imaging and hyperthermia system was proposed. A compact meander line resonator, which exhibited band-pass characteristics and provided narrowband characteristics by using one PIN diode, was fabricated beneath the tapered slot of the wideband TSA to minimize the degradation of the wideband characteristics. Moreover, the electromagnetic energy was transferred to the meander line resonator with a coupling effect to ensure effective frequency switching. By adapting a PIN diode on the meander line resonator, frequency switching could be achieved. In this way, the proposed antenna could operate in a real-time frequency switching mode between the ultra-wideband (UWB; 3.1~10 GHz), which is used for microwave imaging, and the 2.45 GHz band (industrial, scientific, and medical, ISM band), which is used for microwave hyperthermia. Frequency and time-domain results proved the applicability of the proposed antenna to an integrated breast cancer detection and treatment system.

Angle and polarization-independent miniaturized UWB FSS design

2021 ◽  
pp. 1-9
Author(s):  
Yanning Yuan ◽  
Yuchen Zhao ◽  
Xiaoli Xi
Keyword(s):  
Design Method ◽  
Incident Angle ◽  
Stop Band ◽  
Single Layer ◽  
Wireless Systems ◽  
Frequency Selective Surface ◽  
Ultra Wideband ◽  
Band Frequency ◽  
Gain Enhancement ◽  
Polarization Independent

Abstract A single-layer ultra-wideband (UWB) stop-band frequency selective surface (FSS) has several advantages in wireless systems, including a simple design, low debugging complexity, and an appropriate thickness. This study proposes a miniaturized UWB stop-band FSS design. The proposed FSS structure consists of a square-loop and metalized vias that are arranged on a single layer substrate; it has an excellent angle and polarization-independent characteristics. At an incident angle of 60°, the polarization response frequencies of the transverse electric and magnetic modes only shifted by 0.003 f0 and 0.007 f0, respectively. The equivalent circuit models of the square-loop and metallized vias structure are analysed and the accuracy of the calculation is evaluated by comparing the electromagnetic simulation. The 20 × 20 array constitutes an FSS reflector with a unit size of 4.2 mm × 4.2 mm (less than one-twentieth of the wavelength of 3 GHz), which realizes an UWB quasi-constant gain enhancement (in-band flatness is <0.5 dB). Finally, the simulation results were verified through sample processing and measurement; consistent results were obtained. The FSS miniaturization design method proposed in this study could be applied to the design of passband FSS (complementary structure), antennas and filters, among other applications.

Selectivity and in-band impedance enhancement of a compact slot antenna with defected ground structures

2019 ◽  
Vol 11 (10) ◽  
pp. 1010-1016
Author(s):  
Hailong Yang ◽  
Xiaoli Xi ◽  
Lili Wang ◽  
Yuchen Zhao ◽  
Xiaomin Shi
Keyword(s):  
Reflection Coefficient ◽  
Impedance Matching ◽  
Ultra Wideband ◽  
Band Edge ◽  
Slot Antenna ◽  
Defected Ground Structure ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Uwb Antennas ◽  
Low Pass

AbstractIn this study, a new ultra-wideband (UWB) band-edge selectivity antenna with a modified radiation slot using defected ground structure (DGS) is presented to obtain bandpass filtering reflection coefficient and gain performance. The well-designed DGS is designed on backside metallic of the substrate and can be seen as a low-pass filter that provides a good roll-off at a higher frequency. By connecting the DGS and the stepped slot and making them merge with each other, good cut-off property in the upper passband and better in-band impedance characteristics are obtained. Measured results show that the proposed design not only shows good band-edge selectivity in reflection coefficient and gain performance but also has a good impedance matching of −13.5 dB reflection coefficients and a good radiation efficiency of 90% in the operating frequencies. The measured bandwidth defined with the reflection coefficient less than −10 dB is from 3.1–11.2 GHz. Furthermore, the size of the filtering UWB antenna is 22 mm × 12 mm, which is smaller than many individual UWB antennas and UWB filters.

Gradient refractive-index optical rod prepared from methacrylate derivatives

1997 ◽  
Vol 22 (10) ◽  
pp. 668 ◽  
Author(s):  
Jui-Hsiang Liu ◽  
Hung-Tsai Liu
Keyword(s):  
Refractive Index ◽  
Gradient Refractive Index
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