scholarly journals A Reconfigurable Graphene Nanoantenna on Quartz Substrate

2020 ◽  
Vol 19 (5) ◽  
pp. 379-383
Author(s):  
Yanghua Gao ◽  
Weidong Lou ◽  
Hailiang Lu
Keyword(s):  
Reflection Coefficient ◽  
Radiation Pattern ◽  
High Power ◽  
Quartz Substrate ◽  
Miniaturized Antenna ◽  
Thz Applications ◽  
Scattering Losses ◽  
Dynamic Frequency ◽  
Operation Frequency ◽  
Thz Antennas

In the terahertz (THz) band, conventional metallic antennas are virtually infeasible, due to the low mobility of electrons and huge attenuation. The existing metallic THz antennas need a high power to overcome scattering losses, and tend to have a low antenna efficiency. Fortunately, graphene is an excellent choice of miniaturized antenna in millimeter/THz applications, thanks to its unique electronic properties in THz band. Therefore, this paper presents two miniaturized reconfigurable graphene antennas, and characterizes their performance in terms of frequency reconfiguration, omnidirectional radiation pattern, and radiation efficiency. The proposed graphene antennas were printed on a quartz substrate, and simulated on CST Microwave Studio. The results show that the excellence of the proposed antennas in reflection coefficient, dynamic frequency reconfiguration (DFR), and omnidirectional radiation pattern. The operation frequency of the two antennas varies from 0.74 to 1.26 THz and from 0.92 to 1.15 THz, respectively. The proposed antennas have great prospects in wireless communications/sensors.

scholarly journals Feasibility of automotive radar at frequencies beyond 100 GHz

2012 ◽  
Vol 5 (1) ◽  
pp. 49-54 ◽  
Author(s):  
Mike Köhler ◽  
Jürgen Hasch ◽  
Hans Ludwig Blöcher ◽  
Lorenz-Peter Schmidt
Keyword(s):  
Angular Resolution ◽  
Frequency Regulation ◽  
Driver Assistance ◽  
Automotive Radar ◽  
Driver Assistance Systems ◽  
Radar Sensors ◽  
Miniaturized Antenna ◽  
High Resolution Radar ◽  
Assistance Systems ◽  
Operation Frequency

Radar sensors are used widely in modern driver assistance systems. Available sensors nowadays often operate in the 77 GHz band and can accurately provide distance, velocity, and angle information about remote objects. Increasing the operation frequency allows improving the angular resolution and accuracy. In this paper, the technical feasibility to move the operation frequency beyond 100 GHz is discussed, by investigating dielectric properties of radome materials, the attenuation of rain and atmosphere, radar cross-section behavior, active circuits technology, and frequency regulation issues. Moreover, a miniaturized antenna at 150 GHz is presented to demonstrate the possibilities of high-resolution radar for cars.

Reflection coefficient method for antenna radiation pattern measurements

2015 ◽  
Author(s):  
Juha Ala-Laurinaho ◽  
Zhou Du ◽  
Vasilii Semkin ◽  
Ville Viikari ◽  
Antti V. Raisanen
Keyword(s):  
Reflection Coefficient ◽  
Radiation Pattern ◽  
Antenna Radiation ◽  
Antenna Radiation Pattern ◽  
Coefficient Method

scholarly journals Design and Development of a Wideband Planar Yagi Antenna Using Tightly Coupled Directive Element

Micromachines ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 975
Author(s):  
Muhammad A. Ashraf ◽  
Khalid Jamil ◽  
Ahmed Telba ◽  
Mohammed A. Alzabidi ◽  
Abdel Razik Sebak
Keyword(s):  
Reflection Coefficient ◽  
Wireless Communication ◽  
Radiation Pattern ◽  
Excellent Agreement ◽  
Frequency Range ◽  
Fractional Bandwidth ◽  
Yagi Antenna ◽  
Tightly Coupled ◽  
Simulation Results ◽  
Novel Concept

In this paper, a novel concept on the design of a broadband printed Yagi antenna for S-band wireless communication applications is presented. The proposed antenna exhibits a wide bandwidth (more than 48% fractional bandwidth) operating in the frequency range 2.6 GHz–4.3 GHz. This is achieved by employing an elliptically shaped coupled-directive element, which is wider compared with other elements. Compared with the conventional printed Yagi design, the tightly coupled directive element is placed very close (0.019λ to 0.0299λ) to the microstrip-fed dipole arms. The gain performance is enhanced by placing four additional elliptically shaped directive elements towards the electromagnetic field’s direction of propagation. The overall size of the proposed antenna is 60 mm × 140 mm × 1.6 mm. The proposed antenna is fabricated and its characteristics, such as reflection coefficient, radiation pattern, and gain, are compared with simulation results. Excellent agreement between measured and simulation results is observed.

scholarly journals A Compact Dielectric Resonator Antenna Excited by a Planar Monopole Patch for Wideband Applications

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Xuping Li ◽  
Yabing Yang ◽  
Fei Gao ◽  
Hanqing Ma ◽  
Xiaowei Shi
Keyword(s):  
Reflection Coefficient ◽  
Dielectric Resonator ◽  
Ground Plane ◽  
Impedance Bandwidth ◽  
Dielectric Resonator Antenna ◽  
High Radiation ◽  
Ansoft Hfss ◽  
Measurement Results ◽  
Broadside Radiation ◽  
Operation Frequency

A compact dielectric resonator antenna (DRA) suitable for wideband applications is presented in this paper. The proposed antenna is mainly composed by a notched cylindrical dielectric resonator (DR) coated with a metal surface on the top and a finite ground plane where the presented DR is placed. This antenna is very simple in structure and has a very low overall height of0.14λminat its lowest operation frequency. A comprehensive parametric study is carried out based on Ansoft HFSS to optimize the bandwidth. The proposed antenna has been successfully simulated, optimized, fabricated, and measured. The measurement results demonstrate that the proposed design produces an impedance bandwidth of more than 75%, ranging from 2.9 GHz to 6.7 GHz for the reflection coefficient less than −10 dB. In particular, consistent broadside radiation patterns, stable gain, and high radiation efficiency are also obtained within the operation frequency band.

A generalized approach to modeling radiation pattern measurement methods for high-power LEDs

2010 ◽  
Author(s):  
Gao-Wei Chang ◽  
Chia-Cheng Liao ◽  
Yung-Chang Chen
Keyword(s):  
Radiation Pattern ◽  
High Power ◽  
Measurement Methods

scholarly journals A Modified Rectangular Mid-band Microstrip Slot Antenna for WLAN, WiFi and 5G Applications

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Ajay Thatere ◽  
◽  
Sachin Khade ◽  
Vipul Lande S ◽  
◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Reflection Coefficient ◽  
Radiation Pattern ◽  
Current Distribution ◽  
Ground Plane ◽  
Surface Current ◽  
Slot Antenna ◽  
Current Gain ◽  
Wide Bandwidth ◽  
Left And Right

A modified rectangular Microstrip slot antenna for numerous applications like WLAN, Wi-Fi 5, satellite telecommunication and 5G application is portrayed. The proposed antenna has dimension of 25×30×1.6 mm3. The structure consists of partial ground and DGS. The proposed design is embedded on FR4 lossy substrate having dielectric constant of 4.3 and thickness of 1.6 mm. Two similar inverted L shape CLLR are introduced at left and right edge of the ground plane to improve current distribution and to achieve wide bandwidth. The results like reflection coefficient, surface current, gain, directivity, VSWR, impedance and radiation pattern are found up to the mark.

scholarly journals Miniaturized implantable power transmission system for biomedical wireless applications

2020 ◽  
Vol 7 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Shuoliang Ding ◽  
Stavros Koulouridis ◽  
Lionel Pichon
Keyword(s):  
Reflection Coefficient ◽  
Radiation Pattern ◽  
Absorption Rate ◽  
Specific Absorption Rate ◽  
Power Transmission ◽  
Antenna Design ◽  
Wireless Power ◽  
Specific Absorption ◽  
Wireless Applications ◽  
Power Needs

AbstractIn this paper, a complete wireless power transmission scenario is presented, including an external transmission antenna, an in-body embedded antenna, a rectifying circuit, and a powered sensor. This system operates at the Industrial, Scientific, and Medical bands (902.8–928 MHz). For the antenna design, important parameters including reflection coefficient, radiation pattern, and specific absorption rate are presented. As for the rectifying circuit, a precise model is created utilizing off-the-shelf components. Several circuit models and components are examined in order to obtain optimum results. Finally, this work is evaluated against various sensors' power needs found in literature.

Method to Measure Reflection Coefficient Under CW High-Power Signals in SAW Resonators

2021 ◽  
Author(s):  
M Gonzalez-Rodriguez ◽  
Carlos Collado ◽  
Jordi Mateu ◽  
J.M. Gonzalez-Arbesu ◽  
Sebastian Huebner ◽  
...  
Keyword(s):  
Reflection Coefficient ◽  
High Power ◽  
Saw Resonators

Multiport Power Combining Patch Antenna With Stable Reflection Coefficient and Radiation Pattern in Six Polarization States

2019 ◽  
Vol 67 (2) ◽  
pp. 719-729 ◽  
Author(s):  
Wen Duan ◽  
Xiu Yin Zhang ◽  
Shaowei Liao ◽  
Kai Xu Wang ◽  
Quan Xue
Keyword(s):  
Reflection Coefficient ◽  
Radiation Pattern ◽  
Patch Antenna ◽  
Power Combining ◽  
Polarization States
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