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Broadband unidirectional twin-element MIMO antenna scheme for mid-band 5G and WLAN laptops
(2024-12-01)
Luadang, Bancha
;
Janpangngern, Pisit
;
Pookkapund, Khanet
;
Dentri, Sitthichai
;
Krairiksh, Monai
This research proposes a broadband unidirectional twin-element multiple-input-multiple-output (MIMO) antenna scheme for mid-band 5G and WLAN applications. The twin-element antenna scheme comprises two single-element antennas, and each single-element antenna consists of a T-shaped hemispherical feeding patch, left- and right-arm radiating patches, and a conjoined triangular ground plane. The twin-element MIMO antenna scheme is integrated with a laptop model functioning as the reflector. The measured impedance bandwidth (|S<inf>11</inf>|, |S<inf>22</inf>|≤ − 6 dB) are 55.32%, covering 3.4–6.0 GHz, and the measured mutual coupling (|S<inf>12</inf>|) is less than − 15 dB. The measured gain at the center frequency (4.5 GHz) is 4.585 dBi. Besides, the measured xz- and yz-plane cross-polarization levels are below − 25 dB and − 15 dB, respectively. The half-power beamwidth (HPBW) in the xz-plane at 3.5, 4.5, and 5.5 GHz are 99°, 92.8°, and 84.2°, and the corresponding HPBW in the yz-plane are 102°, 78°, and 102°. The measured xz- and yz-plane back lobe levels are below − 15 dB across the entire operating frequency band (3.5–5.5 GHz). The radiation pattern of the twin-element MIMO antenna scheme is of unidirectionality. Furthermore, the envelope correlation coefficient and diversity gain of the twin-element antenna scheme are < 0.001 and > 9.99 dB, respectively. The proposed broadband unidirectional twin-element MIMO antenna scheme is thus operationally suitable for mid-band 5G/WLAN communication systems. Essentially, this research is the first to propose a broadband twin-element MIMO antenna scheme for mid-band 5G/WLAN applications.
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Broadband CP corner-truncated microstrip antenna with irregularly hexagonal AMC for 2.45 GHz applications
(2024-06-01)
Wichaidit, Purichaya
;
Dentri, Sitthichai
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Janpangngern, Pisit
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Lertwiriyaprapa, Titipong
;
Krairiksh, Monai
This research proposes a compact broadband circularly polarized (CP) corner-truncated microstrip antenna with irregularly hexagonal artificial magnetic conductor (AMC) for 2.45 GHz WLAN applications. The corners of the radiating patch are diagonally truncated to realize circular polarization and improve axial ratio. A 5[Formula presented]5 irregularly hexagonal AMC array is employed to enhance the axial ratio bandwidth (ARBW) and antenna gain. In addition, a tri-section meandering feedline is used to realize impedance matching and improve the impedance bandwidth (IBW). The AMC array is used to manipulate electromagnetic waves by suppressing surface currents and back lobe, resulting in reduced back radiation and enhanced front-to-back ratio. The simulated IBW and ARBW are 50.9% (1.86 – 3.13 GHz) and 19.3% (2.24 – 2.72 GHz) respectively, with a maximum gain of 8.9 dBic at 2.45 GHz. The measured IBW and ARBW are 42.42% (1.95 – 3.0 GHz) and 29.4% (2.03 – 2.73 GHz), with a maximum gain of 8.6 dBic. The simulated half power beamwidth (HPBW) of the proposed antenna scheme in the xz plane at 2.24 GHz, 2.45 GHz, and 2.72 GHz are 67°, 62°, and 51°, respectively. The corresponding HPBW in the yz plane are 60°, 55°, and 62°. The simulated AR beamwidth in the xz plane at 2.24 GHz, 2.45 GHz, and 2.72 GHz are 177°, 164°, and 88°, respectively. The corresponding AR beamwidth in the yz plane are 148°, 106°, and 124°. The simulated cross polarized (XP) levels at 2.45 GHz are below -19.35 dB for both planes. The measured HPBW in the xz plane at 2.24 GHz, 2.45 GHz, and 2.72 GHz are 69°, 64°, and 50°, respectively. The corresponding HPBW in the yz plane are 65°, 54°, and 37°. The measured AR beamwidth in the xz plane at 2.24 GHz, 2.45 GHz, and 2.72 GHz are 161°, 200°, and 104°, respectively. The corresponding AR beamwidth in the yz plane are 162°, 85°, and 90°. The measured XP levels at 2.45 GHz are below -15.62 dB for both planes. The radiation pattern is unidirectional. Essentially, the proposed broadband CP antenna scheme is suitable for the WLAN frequency band and other 2.45 GHz wireless communication technologies. The novelty of this research lies in the use of the tri-section meandering feedline and the irregularly hexagonal AMC array to enhance IBW and ARBW.
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Clutter Effect on a Combination of Microwave Imaging and Target Identification Using Ground-Penetrating Radar
(2024-01-01)
Yochanang, Kiattisak
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Bannawat, Lakkhana
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Boonpoonga, Akkarat
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Phongcharoenpanich, Chuwong
This paper presents an experimental investigation of the effect of clutter on the performance of microwave imaging and target identification using ground-penetrating radar (GPR) for buried objects. Signals collected by the GPR were formed to be B-scan and 3D images to carry out the microwave imaging of buried objects. Poles extracted using the short-time matrix pencil method from a late-time response of the received signal collected at a specific position were exploited to identify buried objects. The experiment was set up by constructing a large box filled with sand where an L-shaped metallic sheet was buried. The GPR was installed along with a 2-dimensional scanner above the box to image and identify the buried metallic sheet. In order to investigate the effect of the clutter on the performance of the GPR-based microwave imaging and target identification, small rocks were arranged on the sand surface, and their density was then varied. The experimental results have shown that clutter density significantly affects the sharpness of the B-scan and 3D images. The rocks result in an additional surface layer in the images. Moreover, the results have also shown that the clutter does not affect the performance of the identification of the buried object. From the results, the poles obtained from the GPR scanning inside and outside the buried object region differed. This confirms that the poles of the buried object should be different from those without the object. The poles of the buried object remain constant, although rocks on the sand surface exist since the clutter affects only the early-time response (not the late-time response). With varying clutter densities, the underlying poles were significantly changed, but this does not affect the identification of the buried object.
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Omnidirectional Circularly Polarized Monopole Antennas on Artificial Magnetic Conductor Ground Plane
(2024-01-01)
Janpangngern, Pisit
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Kuse, Ryuji
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Phongcharoenpanich, Chuwong
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Fukusako, Takeshi
This research proposes omnidirectional circularly polarized monopole antennas (OCPA) with single-annular (SA-AMC) and dual-annular artificial magnetic conductor (DA-AMC) ground planes. The aim of the proposed antenna scheme is to circumvent the design rigidity of conventional OCPA whose inherent shortcoming is fixed bottom ground plane size. The OCPA with SA-AMC ground plane consists of a monopole element, four diagonally adjoined parasitic elements to convert linear to circular polarizations, and an SA-AMC ground plane. The OCPA with DA-AMC ground plane consists of a monopole element, four diagonally adjoined parasitic elements, and a DA-AMC ground plane. Unlike the conventional OCPA, the bottom ground plane radius (R-{text {g}}) of the OCPA with SA- and DA-AMC ground planes can be varied between 18.4 - 188.4 mm; and 29.2 - 119.2 mm, respectively, without affecting the omnidirectionality and impedance and axial ratio (AR) bandwidths of the OCPA. Furthermore, the SA- and DA-AMC ground planes effectively improve the impedance (left |{{S-{11}}}right | leq -,10 dB) and AR bandwidths (AR leq 3,{} dB) while reducing leakage current on the coaxial feeder cable. The measured left |{{S-{11}}}right | and AR bandwidths of the OCPA with SA-AMC ground plane, given the optimal R-{g} of 18.4 mm, are 8.08% (5.34 - 5.79 GHz) and 4.38% (5.36 - 5.60 GHz), while those of the OCPA with DA-AMC ground plane, given the optimal R-{text {g}} of 29.2 mm, are 14.37% (5.10 - 5.89 GHz) and 19.85% (4.90 - 5.98 GHz). The novelty of this research lies in the use of SA- and DA-AMC structures to circumvent the design rigidity of the conventional OCPA. Essentially, the integration of the AMC structures offers design flexibility in the realization of OCPA.
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Deployable Wideband Circularly Polarized S-Band Antenna Array for CubeSat Applications
(2024-01-01)
Supreeyatitikul, Nathapat
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Akkaraekthalin, Prayoot
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Kawdungta, Supakit
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Phongcharoenpanich, Chuwong
A broadband circularly polarized (CP) S-band antenna array for CubeSat technology was proposed. The proposed CP antenna array comprised of 2 × 2 rectangular-shaped ring patches and sequentially rotated feeding structure. Besides, the sequentially rotated feeding structure is utilized to match impedance. This antenna is made of single-layered Roger RT5880 substrate. The simulation results at 2 GHz achieved IBW of 81% (1.3 - 2.92 GHz) and ARBW of 25% (1.85 - 2.35 GHz). The optimal RHCP gain is 4.69 dBic at 2.25 GHz. The half-power beamwidth at 2 GHz is 71.51°. The radiation patterns are RHCP characteristic. The proposed CP S-band antenna array with sequentially rotated feeding structure is deployed with the CubeSat platform, resulting in the proposed CP antenna array befitting CubeSat technology.
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Design and Experimentation of CP Sequential-Rotated Patch Antenna for Nanosatellite Technology
(2024-01-01)
Supreeyatitikul, Nathapat
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Phaebua, Kittisak
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Phongcharoenpanich, Chuwong
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Konpang, Jessada
This paper proposes a circularly polarized (CP) sequential-rotated patch antenna for nanosatellite communication systems. The proposed CP sequential-rotated patch antenna comprised of 2 × 2 corner-truncated rectangular patch with a slot, and sequentially rotated feeding (SRF). The SRF was used to improve impedance matching and CP bandwidth. These patches and SRF were fabricated on Rogers 5880 substrate. Moreover, this antenna was integrated with radome and enclosures for space environment hazards. The measured results at 2.1 GHz (center frequency) achieved RLBW of 73.33% (1.46 - 3 GHz) and ARBW of 23.33% (1.87 - 2.36 GHz). The optimal gain (RHCP) was 5 dBic at 2.25 GHz with bi-directional radiation, rendering the proposed antenna suitable for S-band nanosatellite technology.
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Enhancing Bandwidth of Circularly Polarized DRA Using Embedded Slot-Coupled Patch
(2024-01-01)
Supreeyatitikul, Nathapat
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Phongcharoenpanich, Chuwong
;
Konpang, Jessada
This paper proposes a bandwidth enhancement technique for circularly polarized (CP) dielectric resonator antenna (DRA) using the embedded slot-coupled patch. The proposed CP DRA for mid-band 5G applications consisted of an aperture-coupled feed, a dice-shaped dielectric resonator (DR), and an embedded slot-coupled patch. A slot-coupled feed included cross-aperture ground plane (upper substrate) and microstrip-line feed (lower substrate). The dice-shaped DR sits at the center of the cross-aperture ground plane. The slot-coupled patch was embedded into DR for bandwidth enhancement. The DR usually functioned as a resonance cavity, producing TEll1 mode. The embedded slot-coupled patch can generate the resonance frequency mode (TM01 and TMl0) at a higher frequency, resulting in a wide reflection coefficient bandwidth and ARBW. The results of simulation reflection coefficient bandwidth and ARBW at center frequency (3.5 GHz) achieved 44% (3.12 - 4.66 GHz) and 36.57% (3.23 - 4.51 GHz). The peak RHCP gain was 8.7 dBic at 4.5 GHz with right-hand circular polarization, rendering the proposed CP DRA with embedded slot-coupled patch suitable for mid-band 5G wireless networks.
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Wideband Bidirectional Circularly Polarized S-Slot Antenna with Dielectric Superstrate
(2024-01-01)
Luadang, Bancha
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Janpangngern, Pisit
;
Phongcharoenpanich, Chuwong
This paper presents the design of a circularly polarized (CP) wideband S-slot antenna with a bidirectional radiation pattern, using a dielectric superstrate (DS) to increase the gain. The antenna achieves an enhance axial ratio (AR) bandwidth and reduced back lobe of radiation pattern. The S-slot antenna is positioned midway between a rectangular dielectric superstrate and an S-slot radiating element, which has a dielectric constant of εr = 4.3. The DS acts as a lens, refracting the electric field to combine the antenna beam and increase the antenna gain. For performance evaluation, the S-slot radiating element without the DS was compared to the proposed antenna. The antenna size is optimized for a center frequency of 5.5 GHz. The square DS contributes significantly to the bandwidth ratio, achieving an axial ratio AR ≤ 3 dB across the design frequency range (|S11| ≤ -10 dB) of 4.0-6.25 GHz. This antenna design is suitable for wireless communications and 5G sub-6 GHz applications, such as in long bridge/tunnel areas, coal mines communications, radio frequency identification (RFID) systems, and various wireless communication systems.
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T-Slot Antennas-Embedded ZigBee Wireless Sensor Network System for IoT-Enabled Monitoring and Control Systems
(2023-12-01)
Romputtal, Adisak
;
Phongcharoenpanich, Chuwong
This research proposes a 2.4 GHz T-slot antennas-embedded ZigBee wireless sensor network system, consisting of an Internet of Things (IoT) gateway board and a sensor node board, for IoT applications. Simulations were first carried out to optimize the parameters for the T-shaped slot patch antenna. The prototypes of the IoT gateway and sensor node boards were subsequently fabricated and measurements undertaken. The measured impedance matching (|S11|), bandwidth, and gain of the proposed ZigBee sensor network system were -18 dB, 15.38%, and 1.722 dBi, respectively. Furthermore, the ZigBee IoT-based monitoring and control schemes based on the ZigBee wireless sensor network system were set up and experiments carried out in an enclosed area for the monitoring scheme and in an open area for the control scheme. The experimental results revealed that the proposed IoT-enabled 2.4 GHz ZigBee sensor network system with embedded T-slot patch antennas could efficiently be utilized in IoT-based monitoring and control systems. In essence, the novelty of this research lies in the integration of the IoT and ZigBee sensor network technologies to store data in a cloud server in a real-time fashion, as opposed to in the microcontroller memory which is common in conventional ZigBee systems. In addition, the data stored in the cloud server are retrievable and viewable via the Blynk application on smartphone, rendering the proposed 2.4 GHz T-slot antennas-embedded ZigBee wireless sensor network system operationally suitable for IoT-based monitoring and control systems.
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DESIGN OF A COMPACT WIDEBAND BI-DIRECTIONAL PATTERN ANTENNA FOR 5G APPLICATIONS
(2023-07-27)
Lamultree, Suthasinee
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Srisukhot, Supada
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Saetiaw, Charinsak
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Nuangwongsa, Kanawat
;
Phongcharoenpanich, Chuwong
In this research, a wideband bi-directional pattern antenna implemented by a circular monopole encircled with an en-forced-radiation circular ring incorporated with inversed L-shaped stub is designed to operate over the mid-band of 5G applications ranging from 2 to 6 GHz. It is contrived of a copper overlaid on FR4 substrate with relative permittivity of 4.3 and height of 1.6 mm. This proposed antenna is fed by a 50-ohm coplanar waveguide, which is printed on the same side of the radiated circular monopole. To further enrich the impedance matching, a pair of etched slots is added-on the ground plane near the fed line to reduce the return loss. In the study, the initial parameters are theoretically worked out, and then simulation is then performed by using an electromag-netic solutions tool to numerically discover the set of solution parameters. From the simulation results, this proposed antenna offers the |S<inf>11</inf>| < –10 dB covered the operating frequency running from 1.79 to over 8 GHz with fractional bandwidth 126.90 % and 1.74 to 7.07 GHz with fractional bandwidth 101.04 % for the simulation excluded and included SMA, respectively. It provides a linear polarization with total efficiency better than 81.5 %. After that, an antenna prototype with compact dimensions of 45×45×0.6 mm<sup>3</sup> was fabricated and testified to validate the simulation results. The measurement results provide a stability bi-directional pattern with peak gain of 5.54 dBi covering a 10 dB return loss bandwidth of 118.5 % (1.93–7.54 GHz). Simulated |S<inf>11</inf>|, 2D radiation pattern and gain are reasonably in good agreement with experimental results. Furthermore, this proposed antenna is compared with the current compact, wideband and 5G antenna to indicate its prospective for the interested bands.

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