scholarly journals Design and Modeling of New UWB Metamaterial Planar Cavity Antennas with Shrinking of the Physical Size for Modern Transceivers

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Mohammad Alibakhshi Kenari
Keyword(s):  
Transmission Lines ◽  
Patch Antenna ◽  
Patch Antennas ◽  
Frequency Bandwidth ◽  
Left Handed ◽  
Full Wave ◽  
Radiation Properties ◽  
Unit Cells ◽  
Constitutive Parameters ◽  
Large Frequency

A variety of antennas have been engineered with MTMs and MTM-inspired constructs to improve their performance characteristics. This report describes the theory of MTMs and its utilization for antenna's techniques. The design and modeling of two MTM structures withε-μconstitutive parameters for patch antennas are presented. The framework presents two novel ultrawideband (UWB) shrinking patch antennas filled with composite right-/left-handed transmission line (CRLH-TL) structures. The CRLH-TL is presented as a general TL possessing both left-handed (LH) and right-handed (RH) natures. The CRLH-TL structures enhance left-handed (LH) characteristics which enable size reduction and large frequency bandwidth. The large frequency bandwidth and good radiation properties can be obtained by adjusting the dimensions of the patches and CRLH-TL structures. This contribution demonstrates the possibility of reducing the size of planar antennas by using LH-transmission lines. Two different types of radiators are investigated—a planar patch antenna composed of fourO-formed unit cells and a planar patch antenna composed of sixO-shaped unit cells. A CRLH-TL model is employed to design and compare these two approaches and their realization with a varying number ofL-Cloaded unit cells. Two representative antenna configurations have been selected and subsequently optimized with full-wave electromagnetic analysis. Return loss and radiation pattern simulations of these antennas prove the developed concept.

A compact dual-band D-CRLH-based antenna with self-isolation functionality

2021 ◽  
pp. 1-10
Author(s):  
Mahmoud A. Abdalla ◽  
Mohamed El Atrash ◽  
Ahmed A. Abdel Aziz ◽  
Mohamed I. Abdelnaser
Keyword(s):  
Patch Antenna ◽  
Planar Waveguide ◽  
Dual Band ◽  
Resonant Frequencies ◽  
Left Handed ◽  
Directional Radiation ◽  
Full Wave ◽  
Compact Size ◽  
Filtering Function ◽  
Filter Structures

Abstract This paper presents a compact dual-band filtering antenna without extra employing of filter structures. The antenna is designed using a planar dual-composite right/left-handed (D-CRLH) transmission line unit cell, where the filtering function is achieved through current cancellation between the D-CRLH resonators. The antenna is designed to function at 3.0 and 5.1 GHz, which can serve different WLAN applications. The antenna is a co-planar waveguide fed with a very compact size of only 30 × 16 mm2. Compared to the conventional patch antenna, the antenna size is only 17% at 3.0 GHz and 31% at 5.1 GHz. Despite the small size, the antenna preserves a good omni-directional radiation pattern at the two resonant frequencies with a measured realized gain of 2 and 2.7 dB, respectively. At the stopband in-between the two resonant bands, the reflection coefficient is almost 0 dB at 4.25 GHz and complete non-radiation is proved with a −11 dB measured realized gain. The different antenna filtering functions are verified by full-wave simulation and measurements.

Novel Composite Right/Left-Handed Transmission Lines and their Applications in Infinite Wavelength Resonant Antennas

2013 ◽  
Vol 321-324 ◽  
pp. 352-356
Author(s):  
Lin Geng ◽  
Guang Ming Wang ◽  
Ya Wei Wang
Keyword(s):  
Transmission Lines ◽  
Asymmetric Unit ◽  
Wide Bandwidth ◽  
Left Handed ◽  
Unit Cells ◽  
Parameters Analysis

In this paper, two fractal-based composite right/left-handed (CRLH) transmission lines (TLs) are proposed, and their applications in infinite wavelength resonant (IWR) antennas are investigated. In order to impose CRLH properties on the TLs, both the symmetric and asymmetric unit-cells include a gap for series capacitance and Peano-fractal curves for shunt inductance. The circuit parameters analysis shows that the proposed TLs can be used to design miniaturized IWR antennas with extended bandwidth. Then, two fractal-based IWR antennas are designed and fabricated. The measured results show that the fabricated antennas have advantages in terms of small size and wide bandwidth over the reported IWR antennas.

scholarly journals Flexible Design of EGB Structure for Antenna Appliations

2013 ◽  
Author(s):  
Huynh Nguyen Bao Phuong
Keyword(s):  
Patch Antenna ◽  
Ground Plane ◽  
Dual Band ◽  
Flexible Design ◽  
Electromagnetic Bandgap ◽  
High Impedance ◽  
Radiation Properties ◽  
Unit Cells ◽  
Simulation Results ◽  
Good Agreement

In  this paper,  we  present  a  flexible  design of  electromagnetic  bandgap  (EBG)  structure,  which  is constructed  based  on  Fractal  geometry,  for  antenna applications.  These  Fractals,  which  are  the  Sierpinski triangles,  are  arranged  to  repeat  each 600to  introduce the  hexagonal  unit  cells.  By  changing  the  gap  between two adjacent Sierpinski triangles inside EBG unit cell, it can  be  introducing  two  EBG  structuresseparately  that have  broadband  and  dual  bandgap.  By  using  the suspending  microstrip  method, two arrays 3×4  of  EBG unit  cells  areutilized  to  investigate  the  bandgap  of  the EBG  structures.  The  EBG  operation  bandwidth  of  the broadband  structure  and  the  dual-band  structure  are about  87%  and  40%;  35%  at  the  center  bandgap frequencies,  respectively.  Moreover,  a  comparison between  the  broadband  EBG  and  the  conventional mushroom-like  EBG  has  been  done.  Experimental results  of  the  proposed  design  show  good  agreement  in comparison  with  simulation  results.  Finally,  the proposed  EBG  structures  are  studied  as  a  high impedance  ground  plane  for  enhancing  the  radiation properties of a patch antenna.

scholarly journals Leaky wave antenna with amplitude controlled beam steering based on composite right/left-handed transmission lines

2010 ◽  
Vol 8 ◽  
pp. 27-32 ◽  
Author(s):  
M. A. Eberspächer ◽  
T. F. Eibert
Keyword(s):  
Transmission Lines ◽  
Beam Steering ◽  
Main Beam ◽  
Beam Direction ◽  
Leaky Wave ◽  
Microstrip Technology ◽  
Left Handed ◽  
Leaky Wave Antenna ◽  
Wave Antenna ◽  
Unit Cells

Abstract. An antenna comprising two different composite right/left-handed transmission line structures is proposed which enables easy beam steering at an operation frequency of 10 GHz. The composite right/left-handed transmission lines are based on planar, periodically arranged via free unit cells, implemented in microstrip technology. Both transmission lines exhibit the infinite wavelength phenomenon which occurs at 9.72 GHz and 9.89 GHz, respectively. Thus, operating the different leaky wave structures at 10 GHz, radiation with azimuth angles of ±8° and ±17° can be achieved depending on the selected input port. In order to obtain a tunable main beam direction, the radiation patterns of both structures are superimposed by feeding them simultaneously. The influence of each guiding structure, and hence the direction of the main beam, can be controlled via the feeding amplitude. As a result of this, the beam can be steered between ±17° with a gain of up to 10 dBi. The guiding structures are arranged in parallel with a clearance of a=12.2 mm which is less than half of the wavelength in free space. This allows in a further step the attachment of additional guiding structures in order to increase the tunable angle range or creating an antenna array with a small beamwidth in the elevation plane without the occurrence of grating lobes. An antenna prototype was fabricated and validated by measurements.

Tunable microwave devices based on left/right-handed transmission line sections in multilayer implementation

2009 ◽  
Vol 1 (4) ◽  
pp. 323-329 ◽  
Author(s):  
Polina Kapitanova ◽  
Dmitry Kholodnyak ◽  
Stefan Humbla ◽  
Ruben Perrone ◽  
Jens Mueller ◽  
...  
Keyword(s):  
Transmission Line ◽  
Transmission Lines ◽  
Degrees Of Freedom ◽  
Dual Band ◽  
Microwave Devices ◽  
Lumped Element ◽  
Left Handed ◽  
Band Filter ◽  
Unit Cells ◽  
Spurious Response

Metamaterial transmission lines can be realized as a combination of right- and left-handed transmission line (TL) sections exhibiting positive and negative dispersion. This approach gives additional degrees of freedom for improving the performance of microwave devices. Artificial right- and left-handed sections, which are based on lumped-element unit cells consisting of inductance and capacitances (LC-cells), are used. This makes it possible to decrease dimensions of the devices drastically. Furthermore, using variable capacitors in LC-cells allows designing tunable devices. This paper presents the results of design, numerical simulation, and experimental investigation of a tunable rat-race ring and free-of-spurious response dual-band filter manufactured as integrated ceramic multilayer circuits based on low-temperature co-fired ceramics. Commercial semiconductor varactors have been used as tunable components.

Composite right/left-handed transmission line with array of thermocouples for generating terahertz radiation

2020 ◽  
Vol 92 (2) ◽  
pp. 20502
Author(s):  
Behrokh Beiranvand ◽  
Alexander S. Sobolev ◽  
Anton V. Kudryashov
Keyword(s):  
Transmission Line ◽  
Terahertz Radiation ◽  
Transmission Lines ◽  
Software Package ◽  
Optical Pulses ◽  
Capacitively Coupled ◽  
Voltage Difference ◽  
Left Handed ◽  
Microwave Transmission ◽  
Commercial Software Package

We present a new concept of the thermoelectric structure that generates microwave and terahertz signals when illuminated by femtosecond optical pulses. The structure consists of a series array of capacitively coupled thermocouples. The array acts as a hybrid type microwave transmission line with anomalous dispersion and phase velocity higher than the velocity of light. This allows for adding up the responces from all the thermocouples in phase. The array is easily integrable with microstrip transmission lines. Dispersion curves obtained from both the lumped network scheme and numerical simulations are presented. The connection of the thermocouples is a composite right/left-handed transmission line, which can receive terahertz radiation from the transmission line ports. The radiation of the photon to the surface of the thermocouple structure causes a voltage difference with the bandwidth of terahertz. We examined a lossy composite right/left-handed transmission line to extract the circuit elements. The calculated properties of the design are extracted by employing commercial software package CST STUDIO SUITE.

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