A Wideband Absorber of Load Dipoles on a Dielectric Substrate with Inductive Ground Plane

Radio Science ◽  
2019 ◽  
Vol 54 (10) ◽  
pp. 867-875
Author(s):  
Y. M. Chang ◽  
Y. L. Chow ◽  
W. Q. Che
Keyword(s):  
Ground Plane ◽  
Dielectric Substrate

scholarly journals Dual Strip-Excited Dielectric Resonator Antenna with Parasitic Strips for Radiation Pattern Reconfigurability

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
M. Kamran Saleem ◽  
Majeed A. S. Alkanhal ◽  
Abdel Fattah Sheta
Keyword(s):  
Radiation Pattern ◽  
Dielectric Resonator ◽  
Ground Plane ◽  
Dielectric Substrate ◽  
Open Circuit ◽  
Center Frequency ◽  
Dielectric Resonator Antenna ◽  
Excitation Scheme ◽  
Feed Network ◽  
Microstrip Feed

A novel pattern reconfigurable antenna concept utilizing rectangular dielectric resonator antenna (DRA) placed over dielectric substrate backed by a ground plane is presented. A dual strip excitation scheme is utilized and both excitation strips are connected together by means of a 50 Ω microstrip feed network placed over the substrate. The four vertical metallic parasitic strips are placed at corner of DRA each having a corresponding ground pad to provide a short/open circuit between the parasitic strip and antenna ground plane, through which a shift of90°in antenna radiation pattern in elevation plane is achieved. A fractional bandwidth of approximately 40% at center frequency of 1.6 GHz is achieved. The DRA peak realized gain in whole frequency band of operation is found to be above 4 dB. The antenna configuration along with simulation and measured results are presented.

A printed wide-beamwidth circularly polarized antenna via two pairs of radiating slots placed in a square contour

2016 ◽  
Vol 9 (3) ◽  
pp. 649-656 ◽  
Author(s):  
Neng-Wu Liu ◽  
Lei Zhu ◽  
Wai-Wa Choi
Keyword(s):  
Ground Plane ◽  
Large Angle ◽  
Axial Ratio ◽  
Dielectric Substrate ◽  
Slot Antenna ◽  
Radiation Patterns ◽  
Circularly Polarized ◽  
Low Profile ◽  
Orthogonal Pairs ◽  
Good Agreement

A low-profile circularly polarized (CP) slot antenna to achieve a wide axial-ratio (AR) beamwidth is proposed in this paper. The radiating patch consists of two orthogonal pairs of parallel slots etched symmetrically onto a ground plane. Firstly, our theoretical study demonstrates that the CP radiation can be satisfactorily achieved at the broadside, when the vertical and horizontal paired-slots are excited in the same amplitude with 90° phase difference. Secondly, the principle of CP radiation of the proposed antenna on an infinite ground plane is described. Through analyzing the spacing between two parallel slots, the |Eθ| and |Eφ| radiation patterns can be made approximately identical with each other over a large angle range. As such, the slot antenna achieves a wide AR beamwidth. After that, the 3 dB AR beamwidth with respect to the size of a finite ground plane is investigated to constitute a practical CP antenna on a finite ground plane. In final, the proposed CP antenna with a 1–4 probe-to-microstrip feeding network is designed and fabricated on a finite ground plane of a dielectric substrate. Measured results are shown to be in good agreement with the simulated ones about the gain, reflection coefficient, AR bandwidth, and radiation patterns. Most importantly, a wide 3 dB AR beamwidth of 126° and low-profile property with the height of 0.036λ0 are achieved.

scholarly journals Radiation-Scattering–Integrated Design of Multi-Functional Metasurfaces Based on Antenna-Embedded Substrates

2022 ◽  
Vol 8 ◽  
Author(s):  
Xinmin Fu ◽  
Ya Fan ◽  
Yajuan Han ◽  
Jiafu Wang ◽  
Zhuangzhuang Wang ◽  
...  
Keyword(s):  
Antenna Array ◽  
High Efficiency ◽  
Design Method ◽  
Structural Parameters ◽  
Ground Plane ◽  
Integrated Design ◽  
Frequency Selective Surface ◽  
Dielectric Substrate ◽  
Substrate Thickness ◽  
Radiation Scattering

The integration of the metasurface and antenna has brought new vitality to function integration and performance improvement for metasurfaces. In this study, we propose a radiation-scattering–integrated (RSI) design method of functional metasurfaces by incorporating antenna radiators into the substrates. The antenna radiators can also be considered as a band-stop frequency selective surface (FSS) embedded within the dielectric substrate, which adds up to the degree of freedom (DOF) in tailoring electromagnetic (EM) properties of the substrate. In this way, not only radiation function is added to the metasurfaces but also the original scattering-manipulation function is augmented. As an example, we apply this method to the design of a metasurface that can achieve a high radiation gain in-band and low-RCS out-of-band simultaneously. An antenna array was first designed, which uses circular patches as the radiators. Then, the antenna array was used as the substrate of a typical polarization conversion (PC) metasurface. The circular patch lies between the ground plane and the PC meta-atom, providing optimal electrical substrate thickness for PC at two separate bands. By adjusting structural parameters, the operating band of the antenna array can be made to lie in between the two PC bands. In this way, the metasurface can simultaneously possess high-gain radiation function in-band and high-efficiency PC function for RCS reduction out-of-band. A prototype was fabricated and measured. Both the simulated and measured results show that the metasurface can achieve satisfactory radiation gain in-band and significant RCS reduction out of band. This work provides an alternative method of designing multi-functional metasurfaces, which may find applications in smart skins and others.

scholarly journals A High Gain Microstrip Patch Array for 5 GHz WLAN Applications

2018 ◽  
Vol 7 (3) ◽  
pp. 93-98 ◽  
Author(s):  
B. W. Ngobese ◽  
P. Kumar
Keyword(s):  
Ground Plane ◽  
Local Area ◽  
Dielectric Substrate ◽  
High Gain ◽  
Transmission Line Model ◽  
Microstrip Patch ◽  
Model Equations ◽  
5 Ghz ◽  
Standard States ◽  
Good Agreement

This paper presents the design, fabrication and measurement of a high gain 4-elements linear patch array, which uses the corporate feed technique with inset for excitation resonating at 5.216 𝐺𝐻z.  is used as a dielectric substrate for the proposed array structure. The designed array is simulated and optimized by using CST microwave studio software. The element of the array is designed using the transmission-line model equations. The ground plane is made defective by incorporating slots and the reflective ground is utilized to enhance the gain of the array. The simulated and measured results for various parameters of the array are presented. The comparison between simulated and measured results show good agreement with little deviation. The optimized dimensions of the proposed design provides a maximum gain of 9.019 dB and a maximum directivity of 12.81 dBi. The antenna has been designed for the range  which is one of the ranges for  band for wireless local area networks (WLAN) applications as the  standard states.

scholarly journals Design of Ultra Wideband Antenna

2020 ◽  
Vol 8 (5) ◽  
pp. 3988-3990
Keyword(s):  
Return Loss ◽  
Coplanar Waveguide ◽  
Impedance Matching ◽  
Ground Plane ◽  
Dielectric Substrate ◽  
Ultra Wideband ◽  
Impedance Bandwidth ◽  
Uwb Antenna ◽  
Rectangular Patch ◽  
Microstrip Feed

In this paper, A coplanar waveguide (CPW) ultra-wideband(UWB) antenna is designed, analyzed and simulated by computer simulation technology(CST). The proposed antenna is fabricated on FR-4 dielectric substrate. A microstrip feed line is used to excite the antenna.The ground plane is slotted to improve the impedance bandwidth (BW). Here, a rectangular patch is used as radiator and two corners out of four are truncated to improve impedance matching and UWB characterization.This antenna satisfies UWB characteristics like VSWR<2, Return loss(S11)<-10 dB,Gain<5dB and the antenna is operating within the frequency range of 1.59 to 11.87 GHz range which covers whole ultra wideband i.e. 3.1 to 10.6 GHz range.

scholarly journals Modeling of the Power/Ground Plane Noise Including Dielectric Substrate Loss

2010 ◽  
Vol 21 (2) ◽  
pp. 170-178
Author(s):  
Jong-Min Kim ◽  
Ki-Hoon Nam ◽  
Jung-Rae Ha ◽  
Ki-Jae Song ◽  
Wan-Soo Na
Keyword(s):  
Ground Plane ◽  
Dielectric Substrate

scholarly journals Suppression of Mutual Coupling Between Two Microstrip Patch Antennas using a Sophisticated Non-Linear DGS Structure for High Frequency Wave Applications

2018 ◽  
Vol 10 (1) ◽  
pp. 161-184 ◽  
Author(s):  
Lavesh Gupta ◽  
Arun Dev Dhar Dwivedi
Keyword(s):  
Antenna Array ◽  
Mutual Coupling ◽  
Ground Plane ◽  
Microwave Frequency ◽  
Critical Issue ◽  
Dielectric Substrate ◽  
Defected Ground Structure ◽  
Frequency Wave ◽  
Main Motive ◽  
Bottom Side

Purpose – If the two or more than two antennas are present in the antenna array, the mutual coupling between them becomes a critical issue to deal with. At microwave frequency, microstrip design is often used as a transmission line because of its good performance in transferring the energy and microwave signals. Most commonly used microstrip antenna has similar structure as that of the microstrip line. On one side of dielectric substrate layer, is an extremely thin layer of conductor that forms the radiating elements and on bottom side is the ground plane made up of metallic material. Our main motive is to maintain mutual coupling suppressing structure to its simplest form. Methodology/approach/design – We therefore use a Defected Ground Structure (DGS), which greatly decreases the mutual coupling between the two antennas, thus enhancing the performance of the antenna array. Findings – The introduction of the DGS does not affect the characteristics of antenna array system. The Simulation is done using CST (Computer Simulation Technology) software and the results are tested using Vector Network Analyzer. Both the simulated and measured results are in good agreement. The coupling has been reduced from -22 to -37 dB. The recent boom in wireless industry has led to the demand for the multiband antennas.

scholarly journals A Switchable Ultra-Wideband Metamaterial Absorber with Polarization-Insensitivity and Wide-incident Angle at THz Band

2021 ◽  
Vol 8 ◽  
Author(s):  
Liansheng Wang ◽  
Dongyan Xia ◽  
Quanhong Fu ◽  
Xueyong Ding ◽  
Yuan Wang
Keyword(s):  
Incident Angle ◽  
Ground Plane ◽  
Surface Current ◽  
Dielectric Substrate ◽  
Metamaterial Absorber ◽  
Ultra Wideband ◽  
Absorption Mechanism ◽  
Te Mode ◽  
Polarization Insensitivity ◽  
High Absorption

In this paper, we report a switchable ultra-wideband metamaterial absorber with polarization-insensitivity and wide-incident angle at THz band which is composed of VO2 disk, polyimide dielectric substrate, and gold ground plane. The results show that the absorption is greater than 90% from 3.5–8 THz for a temperature of 300 K and this absorption band disappears when the temperature rises to 350 K. The absorption property of our proposed metamaterial absorber is insensitive to polarization states and angles and it can withhold high absorption of more than 80% for wide-incident angles, up to 60° for TE mode and TM mode. The wideband absorption mechanism is elucidated using an effective medium and surface current analysis.

scholarly journals Robust Detection for Chipless RFID Tags Based on Compact Printable Alphabets

Sensors ◽  
2019 ◽  
Vol 19 (21) ◽  
pp. 4785
Author(s):  
Rmili ◽  
Oussama ◽  
Yousaf ◽  
Hakim ◽  
Mittra ◽  
...  
Keyword(s):  
Radio Frequency ◽  
Cross Sections ◽  
Radio Frequency Identification ◽  
Visual Recognition ◽  
Signal To Noise Ratio ◽  
Ground Plane ◽  
Dielectric Substrate ◽  
Rfid Tags ◽  
Robust Detection ◽  
The Impact

This work presents a novel technique for designing chipless radio frequency identification (RFID) tags which, unlike the traditional tags with complex geometries, are both compact and printable. The tags themselves are alphabets, which offers the advantage of efficient visual recognition of the transmitted data in real-time via radio frequency (RF) waves. In this study, the alphabets (e.g., a, b and c) are realized by using copper etching on a thin dielectric substrate (TLX-8) backed by a ground plane. It is shown that the original signature of the frequency response of the backscattered radar cross-section (RCS) of the letter, displays dips that are unique to the individual letters. The tags have been simulated, fabricated and their monostatic cross-sections have been measured by using a dual-polarized Vivaldi antenna in the frequency band ranging from 6 to 13 GHz. The study also includes, for the first time, a detailed analysis of the impact of changing the shape of the tag owing to variation in the font type, size, spacing, and orientation. The proposed letters of the alphabet are easily printable on the tag and provide an efficient way to visually recognized them and, hence, to detect them in a robust way, even with a low coding density of 2.63 bit/cm2. The advantages of the proposed novel identification method, i.e., utilization of the both co- and cross-polar RCS characteristics for the printable clipless RFID tags are the enhancement of the coding density, security and better detection of the alphabet tags with different fonts by capturing the tag characteristics with better signal to noise ratio (SNR). Good agreement has been achieved between the measured and simulated results for both co- and cross-polarized cases.

Modified I-shaped hexa-band near perfect terahertz metamaterial absorber

Circuit World ◽  
2020 ◽  
Vol 46 (4) ◽  
pp. 281-284
Author(s):  
Elakkiya A. ◽  
Radha Sankararajan ◽  
Sreeja B.S. ◽  
Manikandan E.
Keyword(s):  
Ground Plane ◽  
Surface Current ◽  
Dielectric Substrate ◽  
Metamaterial Absorber ◽  
Circular Ring ◽  
Engineering Technology ◽  
Content Type ◽  
Potential Applications ◽  
Material Detection ◽  
Radiation Material

Purpose A novel and simple six-band metamaterial absorber is proposed in the terahertz region, which is composed of an I-shaped absorber and circular ring with four gaps and a continuous metal ground plane separated by only 0.125 mm polyimide dielectric substrate. Initially, I-shaped resonator gives three bands at 0.4, 0.468 and 0.4928 THz with the absorptivity of 99.3%, 97.9% and 99.1%, respectively. The purpose of this paper is to improve the number of bands, for which the authors added the circular ring with four gaps, so the simulated metamaterial absorber exhibited six absorption peaks at 0.3392, 0.3528, 0.3968, 0.4676, 0.4768 and 0.492 THz, with the absorption rate of 91.4%, 94.2%, 94.9%, 90.3%, 77.5% and 97.4%, respectively. The surface current distribution and angle independence are explained for all the six frequencies which are used to analyze the absorption mechanism clearly. Structure maximum uses the squares and circles, so it will make the fabrication easy. The multiband absorbers obtained here have potential applications in many engineering technology, thermal radiation, material detection and imaging and optoelectronic areas. Design/methodology/approach This paper presents the design of the six-band metamaterial absorber which is from the I-shaped resonator and circular ring with four gaps and the metallic ground plane separated by the 0.125 polyimide dielectric substrate. The absorber exhibited six absorption peaks at 0.3392, 0.3528, 0.3968, 0.4676, 0.4768 and 0.492 THz, with the absorption rate of 91.4%, 94.2%, 94.9%, 90.3%, 77.5% and 97.4%, respectively. From the fabrication point of view, the proposed six-band metamaterial absorber has a very simple geometrical structure, and it is very easy to be fabricated. Findings The authors present a new and simple design of six-band absorber based on an I-shaped absorber and circular ring with four gaps and a metallic ground plane separated by a polyimide layer having the thickness of 0.125 mm. Six different resonance absorption peaks are found at 0.3392, 0.3528, 0.3968, 0.4676 , 0.4768 and 0.492 THz. Surface current distribution and angle independence plot have been studied to understand the absorption behavior of the designed terahertz metamaterial absorber. Originality/value The multiband absorbers obtained here have potential applications in many engineering technology, thermal radiation, material detection, security, sensors, imaging and optoelectronic areas.

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