scholarly journals Bandwidth-Enhanced Low-Profile Antenna with Parasitic Patches

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Son Xuat Ta ◽  
Kam Eucharist Kedze ◽  
Dao Ngoc Chien ◽  
Ikmo Park
Keyword(s):  
Ground Plane ◽  
Axial Ratio ◽  
Radiation Efficiency ◽  
Electric Conductor ◽  
Physical Size ◽  
Bandwidth Enhancement ◽  
Antenna Performance ◽  
Low Profile ◽  
Linearly Polarized ◽  
The Cost

This paper presents low-profile broadband antennas, which are composed of four parasitic patches placed between planar radiators and a perfect electric conductor ground plane. Two types of planar radiators, a conventional dipole and a crossed dipole, are employed to produce linearly polarized (LP) and circularly polarized (CP) radiations, respectively. The radiator and parasitic patches are realized on thin substrates to lower the cost. Owing to the presence of parasitic patches, the antenna performance improves in terms of profile reduction, resonant frequency decrease, and bandwidth enhancement. These improvements are discussed and confirmed computationally and experimentally. The LP design with the overall dimensions of 120 mm × 120 mm × 16.3 mm (0.64λ0 × 0.64λ0 × 0.087λ0 at 1.6 GHz) has a |S11| < −10 dB bandwidth of 1.465–1.740 GHz (17.2%), a broadside gain of 8.5–8.8 dBi, and a radiation efficiency > 96%. The CP design, which has the same physical size as the LP case, has a |S11| < −10 dB bandwidth of 1.388–1.754 GHz (23.3%), a 3 dB AR (axial ratio) bandwidth of 1.450–1.685 GHz (15.0%), a right-hand CP broadside gain of 7.8–8.7 dBic, and a radiation efficiency > 90%.

scholarly journals CPW-fed circularly-polarized antenna array with high front-to-back ratio and low-profile

Open Physics ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 651-655 ◽  
Author(s):  
Yilin Liu ◽  
Kama Huang
Keyword(s):  
Antenna Array ◽  
Coplanar Waveguide ◽  
Ground Plane ◽  
Axial Ratio ◽  
Antenna Design ◽  
Impedance Bandwidth ◽  
Feeding Method ◽  
Circularly Polarized ◽  
Low Profile ◽  
Novel Design

Abstract A novel design of a coplanar waveguide (CPW) feed antenna array with circular polarization (CP) and a high front-to-back ratio is described. The proposed CP array is achieved by using a compact CPW–slotline transition network etched in the ground plane. The measured results show that this kind of feeding method can improve the impedance bandwidth, as well as the axial ratio bandwidth of the CP antenna array and provide adequate gain. The proposed array can achieve a 6.08% impedance bandwidth and a 4.10% CP bandwidth. Details of the antenna design and experimental results are presented and discussed.

scholarly journals Beamwidth-Enhanced Low-Profile Dual-Band Circular Polarized Patch Antenna for CNSS Applications

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Hongmei Liu ◽  
Chenhui Xun ◽  
Shaojun Fang ◽  
Zhongbao Wang
Keyword(s):  
Patch Antenna ◽  
Ground Plane ◽  
Axial Ratio ◽  
Dual Band ◽  
Impedance Bandwidth ◽  
Coupled Line ◽  
Low Profile ◽  
Feed Network ◽  
Single Input ◽  
Half Power

A low-profile dual-band circular polarized (CP) patch antenna with wide half-power beamwidths (HPBWs) is presented for CNSS applications. Simple stacked circular patches are used to achieve dual-band radiation. To enhance the HPBW for the two operation bands, a dual annular parasitic metal strip (D-APMS) combined with reduced ground plane (R-GP) is presented. A single-input feed network based on the coupled line transdirectional (CL-TRD) coupler is also proposed to provide two orthogonal modes at the two frequency bands simultaneously. Experimental results show that the 10 dB impedance bandwidth is 32.7%. The 3 dB axial ratio (AR) bandwidths for the lower and upper bands are 4.1% and 6.5%, respectively. At 1.207 GHz, the antenna has the HPBW of 123° and 103° in the xoz and yoz planes, separately. And the values are 127° and 113° at 1.561 GHz.

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 A Triple Band Bow Tie Array Antenna Using Both-sided MIC Technology

2018 ◽  
Vol 8 (5) ◽  
pp. 3038
Author(s):  
Akimun Jannat Alvina ◽  
Samia Sabrin ◽  
Mohammad Istiaque Reja ◽  
Jobaida Akhtar
Keyword(s):  
Impedance Matching ◽  
Axial Ratio ◽  
Array Antenna ◽  
Matching Problem ◽  
Compact Structure ◽  
Antenna Performance ◽  
Linearly Polarized ◽  
Feed Network ◽  
Feed Networks ◽  
Bow Tie

<span>A single-fed linearly polarized 2x2 microstrip bow tie array antenna is proposed. The feed network has microstrip line and slot line where microstrip-slot branch circuit is connected in parallel. The feed network of the array is designed using both-sided MIC Technology to overcome the impedance matching problem of conventional feed networks. The 2x2 half bow tie array antenna is also truncated with spur lines for optimization of antenna performance. The array antenna unit can be realized in very simple and compact structure, as all the antenna elements and the feeding circuit is arranged on a Teflon glass fiber substrate without requiring any external network. The design frequency of the proposed antenna is 5 to 8 GHz (CBand) and the obtained peak gain is 12.41 dBi. The resultant axial ratio indicates that linear polarization is achieved. </span>

scholarly journals A Low-Profile Circularly Polarized Conical-Beam Antenna with Wide Overlap Bandwidth

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Wei He ◽  
Yejun He ◽  
Long Zhang ◽  
Sai-Wai Wong ◽  
Wenting Li ◽  
...  
Keyword(s):  
Electric Field ◽  
Patch Antenna ◽  
Ground Plane ◽  
Axial Ratio ◽  
Impedance Bandwidth ◽  
Beam Radiation ◽  
Circularly Polarized ◽  
Low Profile ◽  
Two Sides ◽  
Conical Beam

In this paper, a low-profile circularly polarized (CP) conical-beam antenna with a wide overlap bandwidth is presented. Such an antenna is constructed on the two sides of a square substrate. The antenna consists of a wideband monopolar patch antenna fed by a probe in the center and two sets of arc-hook-shaped branches. The monopolar patch antenna is loaded by a set of conductive shorting vias to achieve a wideband vertically polarized electric field. Two sets of arc-hook-shaped parasitic branches connected to the patch and ground plane can generate a horizontally polarized electric field. To further increase the bandwidth of the horizontally polarized electric field, two types of arc-hook-shaped branches with different sizes are used, which can generate another resonant frequency. When the parameters of the arc-hook-shaped branches are reasonably adjusted, a 90° phase difference can be generated between the vertically polarized electric field and the horizontally polarized electric field, so that the antenna can produce a wideband CP radiation pattern with a conical beam. The proposed antenna has a wide impedance bandwidth ( ∣ S 11 ∣ < − 10   dB ) of 35.6% (4.97-7.14 GHz) and a 3 dB axial ratio (AR) bandwidth at phi = 0 ° and theta = 35 ° of about 30.1% (4.97-6.73 GHz). Compared with the earlier reported conical-beam CP antennas, an important feature of the proposed antenna is that the AR bandwidth is completely included in the impedance bandwidth, that is, the overlap bandwidth of ∣ S 11 ∣ < − 10   dB and AR < 3   dB is 30.1%. Moreover, the stable omnidirectional conical-beam radiation patterns can be maintained within the whole operational bandwidth.

scholarly journals Configurable Defected Ground Structures for Low Profile Antenna Performance Enhancement

2020 ◽  
Author(s):  
Yujie Zhang ◽  
Zixiang Han ◽  
Shanpu Shen ◽  
Chi Yuk Chiu ◽  
Ross Murch
Keyword(s):  
Mutual Coupling ◽  
Performance Enhancement ◽  
Single Port ◽  
Axial Ratio ◽  
Cross Polarization ◽  
Antenna Performance ◽  
Low Profile ◽  
Low Profile Antennas ◽  
Defected Ground Structures ◽  
Ground Structures

<div>Versatile configurable defected ground structures</div><div>(CDGSs) for enhancing the performance of low profile antennas are introduced. It is shown that CDGS can significantly reduce mutual coupling (MC) between multiple antennas and suppress cross-polarization (XP) and enhance circular polarization (CP) excitation in single port low profile antennas for example. The key idea of CDGS is to construct defected ground structures (DGSs) from a grid of slots, which can be either opened or shorted with hardwires, so that they can be configured and optimized to enhance desired antenna performance characteristics. The</div><div>importance and versatility of the CDGS approach is that it</div><div>overcomes the issue of having to design bespoke DGS for each individual antenna design. Three design examples are provided to demonstrate the versatility of CDGSs for MC reduction, XP suppression and CP excitation. Experimental results demonstrate that MC can be reduced by up to 43 dB, XP can be suppressed by 15 dB and CP can be excited with 78 MHz (2.2%) 3-dB axial ratio (AR) bandwidth. The compactness and ease of fabrication also make the CDGS well suited to compact low profile internet of things (IoT) and wireless communication applications.</div>

scholarly journals Coplanar Waveguide-Fed Bidirectional Same-Sense Circularly Polarized Metasurface-Based Antenna

2021 ◽  
Vol 21 (3) ◽  
pp. 210-217
Author(s):  
Cho Hilary Scott Nkimbeng ◽  
Heesu Wang ◽  
Ikmo Park
Keyword(s):  
Reflection Coefficient ◽  
Coplanar Waveguide ◽  
Ground Plane ◽  
Axial Ratio ◽  
Radiation Efficiency ◽  
Impedance Bandwidth ◽  
Antenna Gain ◽  
Circularly Polarized ◽  
Feed Line

This paper presents the design of a bidirectional same-sense circularly polarized (CP) antenna that uses metasurfaces. The antenna consists of two metasurfaces, each comprising an array of 2 × 4 corner truncated patches placed back-to-back on the top and bottom of the antenna. In addition, a ground plane with an etched slot is sandwiched between the substrates at the front and back, and the feed line is a 50 Ω coplanar waveguide. The antenna radiates same-sense right-handed CP waves in both the front and back directions and has overall dimensions of 48 mm × 24 mm × 3.048 mm (0.91λo × 0.45λo × 0.05λo at 5.7 GHz). The measured reflection coefficient for |S11| < -10 dB yields an impedance bandwidth of 5.21–6.26 GHz (18.4%) and an axial ratio (AR) bandwidth of 5.36–6 GHz (11.2%) for both front and back directions. The antenna gain is 3–5.29 dBic for both directions and has a radiation efficiency of >96% within its AR bandwidth.

scholarly journals A Low-Profile Wideband Linear-to-Circular Polarization Conversion Slot Antenna Using Metasurface

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1164 ◽  
Author(s):  
Jian Dong ◽  
Chang Ding ◽  
Jinjun Mo
Keyword(s):  
Circular Polarization ◽  
Satellite Communication ◽  
Axial Ratio ◽  
Slot Antenna ◽  
Impedance Bandwidth ◽  
Polarization Conversion ◽  
Compact Structure ◽  
Low Profile ◽  
Unit Cells ◽  
Linearly Polarized

A new low-profile wideband linear-to-circular polarization conversion microstrip slot antenna based on a metasurface for C-band satellite communication applications is proposed in this paper. The metasurface basically consists of four unit cells with parasitic square cross gaps arranged in a 2 × 2 layout. By loading the metasurface on the microstrip slot antenna, linearly polarized (LP) waves from the source antenna are converted into circularly polarized (CP) waves. Then, by etching three more parasitic square cross gaps in the middle of the metasurface, enhanced impedance bandwidth and axial ratio bandwidth (ARBW) are achieved. Furthermore, an equivalent circuit and a phase analysis are presented to explain how a wide ARBW is realized by the metasurface. A final model with an overall size of 36 × 36 × 3.5 mm3 (approximately 0.65λ0 × 0.65λ0 × 0.06λ0 at 5.5 GHz) was designed and fabricated. The measured S11 bandwidth and 3 dB ARBW were 39.25% from 4.28 GHz to 6.37 GHz and 17.77% from 5.18 GHz to 6.19 GHz, respectively. As a result, the proposed antenna shows great potential for satellite communication applications due to its low profile and compact structure, wide impedance bandwidth, and wide axial ratio bandwidth.

scholarly journals Small Antennas for Wearable Sensor Networks: Impact of the Electromagnetic Properties of the Textiles on Antenna Performance

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5157
Author(s):  
Gabriela Atanasova ◽  
Nikolay Atanasov
Keyword(s):  
Sensor Networks ◽  
Loss Tangent ◽  
Rapid Development ◽  
Substrate Material ◽  
Radiation Efficiency ◽  
Electromagnetic Properties ◽  
Textile Materials ◽  
Antenna Performance ◽  
Low Profile ◽  
The Impact

The rapid development of wearable wireless sensor networks (W-WSNs) has created high demand for small and flexible antennas. In this paper, we present small, flexible, low-profile, light-weight all-textile antennas for application in W-WSNs and investigate the impact of the textile materials on the antenna performance. A step-by-step procedure for design, fabrication and measurement of small wearable backed antennas for application in W-WSNs is also suggested. Based on the procedure, an antenna on a denim substrate is designed as a benchmark. It demonstrates very small dimensions and a low-profile, all while achieving a bandwidth (|S11| < −6 dB) of 285 MHz from 2.266 to 2.551 GHz, radiation efficiency more than 12% in free space and more than 6% on the phantom. Also, the peak 10 g average SAR is 0.15 W/kg. The performance of the prototype of the proposed antenna was also evaluated using an active test. To investigate the impact of the textile materials on the antenna performance, the antenna geometry was studied on cotton, polyamide-elastane and polyester substrates. It has been observed that the lower the loss tangent of the substrate material, the narrower the bandwidth. Moreover, the higher the loss tangent of the substrate, the lower the radiation efficiency and SAR.

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