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This paper presents the performance of a planar, low-profile, and wide-gain-bandwidth leaky-wave slit antenna in different thickness
values of high-permittivity gallium arsenide substrates at terahertz frequencies. The proposed antenna designs consisted of a periodic array
of 5 × 5 metallic square patches and a planar feeding structure. The patch a...
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... electro- magnetic wave simulator CST Microwave Studio (CTS Computer Simulation Technology GmbH, Darmstadt, Ger- many) based on the finite integration time domain technique. The antenna was excited by the default Gaussian-shaped signal in the desired frequency range by placing a discrete port in the dipole gap at the center of the slit line. Fig. 2 shows the gain characteristics of antennas at differ- ent substrate thickness values. As the thickness, H, of the substrate decreased from H = 160 μm to H = 20 μm, the gain response shifted to higher frequencies. In fact, the change in the substrate thickness changed the effective per- mittivity. Thus, the gain response shifted to ...
Citations
... The slots in both sub arrays are excited by lumped element edge port excitation technique with 50 Ω impedance [25], [26]. Figure 4 (a) shows lumped element excitation assigned to all the elements of sub array 1 and figure 4 (b) shows port excitation assigned for single slot. ...
... The slots in both sub arrays are excited by lumped element edge port excitation technique with 50 Ω impedance [25], [26]. Figure 4 (a) shows lumped element excitation assigned to all the elements of sub array 1 and figure 4 (b) shows port excitation assigned for single slot. ...
... 19 The metamaterial-based antennas are being developed for various communication systems. [20][21][22][23][24][25][26][27][28] Although there are limited studies on 5G (28 GHz band) antennas using metamaterial, these antennas have disadvantages of low gain. [24][25][26][27][28] Recently, the gain of the patch antenna was improved by using two copper conductive concentric rings having DNG characteristics placed on the substrate. ...
This paper presents the performance improvement of a microstrip patch antenna (MPA) using a novel double‐layer concentric rings metaplate (DLCRM) for fifth‐generation (5G) millimeter wave (mmWave) applications. To improve the performance of the proposed antenna, a DLCRM is placed above the MPA having an air gap. The design procedure is explained using the different shapes of DLCRM, and the double negative (DNG) characteristic of metamaterial is verified. Moreover, the effects of the DLCRM on the MPA are validated by experimental results. The proposed antenna attains a high‐gain of 11.59 dBi and has an impedance bandwidth from 27.1 GHz to 29.56 GHz (8.68%) which is the potential 5G mmWave band. The measurement result shows that the bandwidth of the antenna is improved by 2.04%, and broadside gain is increased by 4.69 dBi compared to the MPA without a DLCRM. Thus, the antenna provides high gains with wide bandwidth that makes it a suitable candidate for 5G mmWave applications.
... Lens-coupled antennas undergo the disadvantages of fabrication complexity and low radiation efficiencies [4]. On the other hand, Fabry-Perot cavities [5], and the metasurfaces/metamaterial [6][7][8][9][10][11][12][13] have also been used to increase the gain of antennas. However, the metasurfaces unit cells need optimization of complex design having huge design parameters. ...
This paper presents the design and characterization of a microstrip patch antenna with multiple superstrates for performance enhancement operating at the central frequency of 5.5 GHz for high-gain WLAN applications. The performance of the antenna in terms of reflection loss and the gain are investigated using multiple high dielectric constant superstrates of Taconic CER-10 (εr=10.2). Numerical results showed that the patch antenna has-10 dB impedance bandwidth of 2.54% which improves to 8.43% and 17.43% by employing a single and dual superstrate, respectively. The gain of the antenna increases from 6.1 dBi to 9.5 dBi using a single superstrate, which further enhances to 13.6 dBi by placing two optimized superstrates. Moreover, further increasing the number of superstrates did not significantly impact on the performance of the patch antenna. The final design of the antenna (patch antenna with two superstrates) is fabricated and measured. The measured results agree well with the simulated results. Due to the good impedance matching, high-gain and desired radiation patterns compared to the other superstrate antennas, this antenna is a good candidate for high-gain WLAN applications.
... Although, the antennas with multiple stacked substrates without air gap have wideband CP radiations [9,10] but have the drawbacks of complex design and non-planar structures. On the other hand, metasurfaces which are the twodimensional equivalent of the metamaterials are combined with radiators to achieve wideband AR and gain enhancement, while keeping the low-profile of the antennas [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. Essentially the metasurface (MTS) is placed either above [11][12][13][14][15][16] or below [17][18][19][20][21] the radiator with an air gap. ...
... These configurations have design complexities, highprofiles, and poor mechanical properties because of the air gap. Alternatively, the MTS is directly stacked on the radiator without any air gap to design low-profile wideband CP antennas [22][23][24][25][26][27][28][29]. However, these designs are at microwave frequencies. ...
!This paper presents the design and realization of a metasurface-based low-profile wideband Circularly Polarized (CP) patch antenna with high performance for Fifth-generation (5G) communication systems. The antenna consists of a modified patch, sandwiched between an array of 4 × 4 symmetrical square ring Metasurface (MTS) and a ground plane. Initially, the intrinsic narrow bandwidth of the conventional patch antenna is increased using a diagonal rectangular slot. For further performance enhancement, the additional resonances and CP radiations are achieved for wideband operation in terms of impedance and Axial Ratio (AR) by effective excitation of surface waves propagating along the MTS. The stacking of MTS on the modified patch without any air gap resulted in an overall compact size of 1.1λ0 × 1.1λ0 × 0.093λ0. Simulated and measured results show that the MTS-based antenna offers a wide impedance bandwidth ranging from 24 – 34.1 GHz (34.7%) for |S11| < -10 with a maximum gain of 11 dBic and a 3-dB AR bandwidth of 24.1 – 29.5 GHz (20.1 %). Moreover, the proposed antenna has a smooth gain response with a small variation in its gain (9.5 – 11 dBic) and a stable left-hand CP radiation in the desired frequency range. The operating bandwidth of this antenna is covering the proposed entire global millimeter-wave spectrum (24.2 – 29.5 GHz) for 5G communication systems.
... Metasurface based antennas have emerged as proposed alternatives to the traditional bulky antenna configurations because of their low fabrication cost, low profile, wide operational impedance bandwidth and gain 3,5,26 . Metasurfaces, act as local gradient phase shifters of the incident electromagnetic waves (EM), and serve to modify the wavefronts of the incident EM waves 3,13,24,27,28 . ...
This work presents a novel design of a high gain circularly polarized (CP) crossed‐bowtie shaped antenna with cloverleaf arms which exhibits a wideband impedance match as well as 3dB axial ratio bandwidths. The designed wideband antenna is realized by employing a low‐cost phase shifting mechanism that uses a Metasurface (MTS) superstrate which is placed above the radiating surface of the antenna. A design chart is developed for the determination of the required phase variation based on the distance between MTS and the antenna radiator. Next, the concept of MTS placement above the antennas is extended to the cases of 3x3 and 5x5 cloverleaf‐shaped bowtie antenna arrays, with the goal of improving the gain and sidelobe levels (SLLs). The study includes a systematic analysis of the variation in gain and SLL of CP antenna arrays as we change the number of elements of the superstrate.
... Recently, metasurfaces based antennas have obtained a lot of attention of researchers and academia. Metasurface, which can artificially control electromagnetic waves has the advantage of small geometric size, high gain, side/back lobe suppression, and wide bandwidth [1]- [6]. ...
This paper presents the design of a high gain parabolic antenna by using reflection gradient metasurface. The metasurface is consisting of a series of asymmetrical square patches on a grounded dielectric substrate. A patch antenna is located at the focal point of the metasurface as a feed source. Due to the effective utilization of metasurface, the electromagnetic wave reflected and concentrated, which resulted in high of the antenna. The antenna has an impedance bandwidth ranging from 12.076 GHz-13. 152 GHz for S11 <-10 dB with a high-gain up to 20.5 dB. Thus, the proposed antenna is suitable for long-distance communication systems requiring high-gain.
... The is why antennas having high-gain characteristics are highly recommended for MMW communications. Conventionally high gain characteristics are offered by array antennas [3], metasurface/metamaterial antennas [4]- [9], lens-coupled antennas [10], and Fabry-Perot cavity antennas [11]- [12]. A high-gain and wide-band antenna covering the whole allocated global spectrum for 5G with an additional advantage of circular polarization would be an important step to realize future communication systems. ...
This paper presents the design of a wideband circularly polarized Fabry-Perot cavity antenna for millimeter-wave (MMW) applications. The circular polarization is achieved by utilizing a corner cut patch with a diagonal slot, while the Fabry-Perot cavity is realized by placing a half-wavelength thick dielectric superstrate above the radiator for gain and bandwidth enhancement. Simulated and measured results show that the proposed design has a wide-bandwidth of 27.6 % (25-33 GHz) 27.6%) for |S11| <-10 dB. The antenna also offers a stable gain with a maximum value of 14.1 dBi, and a wide 3-dB axial ratio bandwidth ranging from 26-31.3 GHz (17%). This operational bandwidth of the antenna covers the proposed entire global MMW spectrum (26-29.5 GHz) for 5G applications.
... 4-7 Some antennas with the stacked patches achieve filtering performance, 5-7 but they have a large physical size which may limit its integration with the modern 5G devices. On the other hand, metasurfaces are widely used in antenna design for the enhancement of gain, 8 increasing bandwidth, 9 polarization conversion, 10 and filtering response. 11,12 The filtering antennas using metasurface or metamaterial show highgain and filtering characteristics, however, it has also the disadvantages of large size due to air gap between the radiator and the metamaterial/metasurface. ...
This article presents a low‐profile filtering antenna based on nonuniform metasurface for fifth generation (5G) systems at 3.5 GHz. A crossed stub, slotted ground, shorting via, and the nonuniform metasurface is used to achieve high gain and filtering response in lower and upper stopbands. The antenna and the metasurface are printed on Rogers RO4003C (εr = 3.38, tan δ = 0.0027) and Taconic TLX‐9 (εr = 2.5, tan δ = 0.0019), respectively. Measured results show that the antenna has an impedance bandwidth of 3.24 to 3.8 GHz (15.91%) below −10 dB with a stable gain having a maximum value of 10.43 dBi and good radiation patterns. Moreover, this antenna passband satisfies the typical bandwidth required for the global 5G spectrum at the 3.5 GHz band. The gain drops significantly and the S11 goes up to 0 dB outside the passband. Due to the excellent filtering characteristics, the proposed antenna is a good candidate for 5G applications.
... The use of metamaterial is a promising technology for performance enhancement, miniaturization, and easy fabrication of antennas. [10][11][12][13] Metamaterial's permeability (μ) and dielectric constant (ε r ) parameters are set to negative values at the same frequency. Under this condition, the electromagnetic wave is refracted in the opposite direction, and the focus is caused by this material. ...
This article presents a millimeter‐wave (mmWave) microstrip patch antenna (MPA) with a vertically coupled split ring metaplate (VCSRM). The narrow bandwidth and low gain of MPA are improved using VCSRM by periodically arranging split rings on the front and backsides of a dielectric slab. Numerical and experimental results show that the proposed antenna attains good radiation pattern, a high gain of 11.94 dBi, and a measured fractional bandwidth covering 26.58 to 29.31 GHz (9.77%). The gain of the antenna is increased by 5.35 dBi and the bandwidth is improved by 3.87% when compared to MPA without VCSRM. Thus, the proposed antenna with a small size of 18 × 22 mm2 is suitable for mmWave applications.
