scholarly journals UWB Miniature Antenna Based on the CRLH-TL with Increase Gain for Electromagnetic Requirements

2014 ◽  
Vol 3 (1) ◽  
pp. 61 ◽  
Author(s):  
M. A. Kenari ◽  
M. N. Moghadasi
Keyword(s):  
Transmission Line ◽  
Free Space ◽  
Ultra Wideband ◽  
Operating Frequency ◽  
Maximum Efficiency ◽  
Radiation Patterns ◽  
Left Handed ◽  
Unit Cells ◽  
Miniature Antenna ◽  
Peak Gain

In this paper, a novel ultra-wideband (UWB) miniature antenna based on the composite right-left handed transmission line (CRLH-TL) structure with enhancement gain is proposed and investigated. With CRLH metamaterial (MTM) technology embedded, the proposed UWB and miniature antenna is presented with best in bandwidth, size, efficiency and radiation patterns. To realize characteristics of the antenna, the printed -shaped gaps into the rectangular radiation patches are used. This antenna is constructed of the two unit cells, also presented antenna is designed from 2.25 GHz to 4.7 GHz which corresponding to 70.5% bandwidth. The overall size of the presented antenna is 10.8mm×6.9mm×0.8mm or 0.09λ0× 0.05λ0 × 0.006λ0 at the operating frequency f = 2.5 GHz (where λ0 is free space wavelength). The radiation peak gain and the maximum efficiency which occurs at 4.6 GHz, are 3.96dBi and 63.6%, respectively.

Introducing the new wideband small plate antennas with engraved voids to form new geometries based on CRLH MTM-TLs for wireless applications

2014 ◽  
Vol 6 (6) ◽  
pp. 629-637 ◽  
Author(s):  
Mohammad Alibakhshi
Keyword(s):  
Transmission Line ◽  
Free Space ◽  
Model Parameters ◽  
Transmission Line Model ◽  
Physical Size ◽  
Wireless Applications ◽  
Small Antennas ◽  
Left Handed ◽  
Unit Cells ◽  
Operational Frequency

In this paper, four new wideband small antennas based on the composite right/left-handed transmission line (CRLH-TL) structures are designed, tooled, and made. The proposed antennas are introduced with best in size, bandwidth, and radiation patterns. The physical size and the operational frequency of the antennas depend on size of the unit cells and the equivalent transmission line model parameters of the CRLH-TLs, including series inductance, series capacitance, shunt inductance, and shunt capacitance. To define characteristics of the antennas, the engraved J- and I-formed voids on the radiation patches are used. The physical sizes of the CRLH antennas are 0.45λ0 × 0.175λ0 × 0.02λ0, 0.428λ0 × 0.179λ0 × 0.041λ0, 0. 564λ0 × 0.175λ0 × 0.02λ0, and 0.556λ0 × 0.179λ0 × 0.041λ0 in terms of free-space wavelengths at the 7.5, 7.7, 7.5, and 7.7 GHz, respectively. These metamaterial antennas can be used for frequency bands from 7.5–16.8 GHz, 7.7–18.6 GHz, 7.25–17.8 GHz, and 7.8–19.85 GHz for VSWR < 2, which correspond to 74.4, 82.88, 84.23, and 87.16% practical bandwidths, respectively. Also, the ranges of the measured gains and radiation efficiencies of the recommended antennas are 0.1 dBi < G < 2.1 dBi and 20% < eff < 44.3%, and 0.8 dBi < G < 2.35 dBi and 23% < eff < 48.2%, for J-shaped antennas, whereas 0.1.15 dBi < G < 3.11 dBi and 30.24% < eff < 58.6%, and 1.2 dBi < G < 3.4 dBi and 32.4% < eff < 68.1% for I-shaped antennas, respectively.

scholarly journals Bandwidth and gain enhancement of composite right left handed metamaterial transmission line planar antenna employing a non foster impedance matching circuit board

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mohammad Alibakhshikenari ◽  
Bal S. Virdee ◽  
Ayman A. Althuwayb ◽  
Leyre Azpilicueta ◽  
Naser Ojaroudi Parchin ◽  
...  
Keyword(s):  
Transmission Line ◽  
Impedance Matching ◽  
Circuit Board ◽  
Operating Frequency ◽  
Planar Antenna ◽  
Effective Technique ◽  
Input Capacitance ◽  
Gain Enhancement ◽  
Microstrip Patch ◽  
Left Handed

AbstractThe paper demonstrates an effective technique to significantly enhance the bandwidth and radiation gain of an otherwise narrowband composite right/left-handed transmission-line (CRLH-TL) antenna using a non-Foster impedance matching circuit (NF-IMC) without affecting the antenna’s stability. This is achieved by using the negative reactance of the NF-IMC to counteract the input capacitance of the antenna. Series capacitance of the CRLH-TL unit-cell is created by etching a dielectric spiral slot inside a rectangular microstrip patch that is grounded through a spiraled microstrip inductance. The overall size of the antenna, including the NF-IMC at its lowest operating frequency is 0.335λ0 × 0.137λ0 × 0.003λ0, where λ0 is the free-space wavelength at 1.4 GHz. The performance of the antenna was verified through actual measurements. The stable bandwidth of the antenna for |S11|≤ − 18 dB is greater than 1 GHz (1.4–2.45 GHz), which is significantly wider than the CRLH-TL antenna without the proposed impedance matching circuit. In addition, with the proposed technique the measured radiation gain and efficiency of the antenna are increased on average by 3.2 dBi and 31.5% over the operating frequency band.

scholarly journals Design of composite right/left-handed transmission line for phase shifter of multi-band base station antenna

2018 ◽  
Vol 5 ◽  
pp. 12
Author(s):  
Naobumi Michishita ◽  
Yoshihide Yamada ◽  
Keizo Cho
Keyword(s):  
Phase Shift ◽  
Transmission Line ◽  
Phase Shifter ◽  
Vertical Plane ◽  
Equivalent Circuit Model ◽  
Base Station ◽  
Unit Cell ◽  
Operating Frequency ◽  
Left Handed ◽  
Multi Band

In multi-band base station antennas, interference toward neighboring cells at low operating frequency in-creases since tilting angle is frequency-independent and beamwidth in the vertical plane increases as de-creasing the operating frequency. In this paper, the realization of the different phase shifts at each frequency is proposed by using the dispersion relation of the composite right/left-handed transmission line. The feasi-bility of the phase shift is clarified by using equivalent circuit model of the unit cell. Next, the dispersion and Bloch impedance of the actual configuration of the unit cell are designed. The inverse phase shift at each frequency is verified experimentally.

scholarly journals A Novel Dual-Band MIMO Antenna with Lower Correlation Coefficient

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Jian Zhang ◽  
Jun OuYang ◽  
Kai Zhi Zhang ◽  
Feng Yang
Keyword(s):  
Correlation Coefficient ◽  
Free Space ◽  
Dual Band ◽  
Radiation Patterns ◽  
Commercial Software ◽  
Matching Effect ◽  
Mimo Antenna ◽  
Lower Band ◽  
Lower Correlation ◽  
Peak Gain

This paper demonstrates a novel dual-band operated MIMO antenna which consisted of planar monopole (main antenna) and 3D slot element (auxiliary antenna). The main antenna is printed on a 1.6 mm thick FR4 board, while the auxiliary antenna is fabricated with gold-coated copper. A lumped impedance network is applied to enhance matching effect at port1. From simulations by commercial software, it can be found that the proposed antenna is able to cover GSM800, GSM900 (lower band), and LTE/ WiMAX/WLAN (higher band) quite well. Good agreements between simulations and measurements are obtained. Corresponding measured results, antenna efficiency, peak gain, and radiation patterns, are presented at the same time. By equipping a passive decoupling element, the coupling power on the ground is radiated into free space, and great enhancement of isolation between antenna elements, especially for lower band, is achieved.

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