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A Flexible and Compact UWB MIMO Antenna with Dual-Band-Notched Double U-Shaped Slot on Mylar® Polyester Film
(2025-09-01)
Chutchavong, Vanvisa
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Chanwattanapong, Wanchalerm
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Wongsin, Norakamon
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Rakluea, Paitoon
;
Tangjitjetsada, Maleeya
Ultra-wideband (UWB) technology is a crucial facilitator for high-data-rate wireless communication due to its extensive frequency spectrum and low power consumption. Simultaneously, multiple-input multiple-output (MIMO) systems have garnered considerable attention owing to their capability to enhance channel capacity and link dependability. This article discusses the development of small, high-performance MIMO UWB antennas with mutual suppression capabilities to fully use the benefits of both technologies. Additionally, the suggested antenna features a straightforward design and dual-band-notched characteristics. The antenna structure includes two radiating elements measuring 85 × 45 mm<sup>2</sup>. These elements use a rectangular patch provided by a coplanar waveguide (CPW). Double U-shaped slots are incorporated into the rectangular patch to introduce dual-band-notched properties, which help mitigate interference from WiMAX and WLAN communication systems. The antenna is fabricated on a Mylar<sup>®</sup> polyester film substrate of 0.3 mm in thickness, with a dielectric constant of 3.2. According to the measurement results, the suggested antenna functions efficiently across the frequency spectrum of 2.29 to 20 GHz, with excellent impedance matching throughout the bandwidth. Furthermore, it provides dual-band-notched coverage at 3.08–3.8 GHz for WiMAX and 4.98–5.89 GHz for WLAN. The antenna exhibits impressive performance, including favorable radiation attributes, consistent gain, and little mutual coupling (less than −20 dB). Additionally, the envelope correlation coefficient (ECC) is extremely low (ECC < 0.01) across the working bandwidth, which indicates excellent UWB MIMO performance. This paper offers an appropriate design methodology for future flexible and compact UWB MIMO systems that can serve as interference-resilient antennas for next-generation wireless applications.
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Broadband Two-Array Metasurface-Gridded MIMO Antenna with Dual-CP Bi-Directional Capabilities
(2025-01-01)
Supreeyatitikul, Nathapat
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Kakhong, Khwanlada
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Prasong, Pusit
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Phongcharoenpanich, Chuwong
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Konpang, Jessada
This study presents a novel two-array MTS-gridded MIMO antenna with dual circular polarization (CP) bidirectional capabilities for full-duplex communications. The proposed antenna consists of two mirrored clusters, each comprising a single-element antenna formed by a 3 × 4 MTS-gridded element array, a circular patch, and a ground plane. The antenna demonstrates a wide measured return loss bandwidth (RLBW) of 56.46% (5 - 8.67 GHz), axial ratio bandwidth (ARBW) of 18.15% (6.26 - 7.44 GHz), and strong isolation below -22 dB. Peak gains of 6.5 dBic and 6.55 dBic were observed at 6.6 GHz and 6.54 GHz for Ports 1 and 2, respectively. Furthermore, the low envelope correlation coefficient (< 0.005) and high diversity gain (> 9.985 dB) validate its effectiveness for multi-port applications. The bidirectional radiation pattern and dual circular polarization support simultaneous transmission and reception, making the design well-suited for full-duplex MIMO operation.
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Two-Port Circularly Polarized Slot-Coupled Antenna Using Novel AMC Structure
(2025-01-01)
Supreeyatitikul, Nathapat
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Kakhong, Khwanlada
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Phongcharoenpanich, Chuwong
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Konpang, Jessada
This research introduces a two-port circularly polarized (CP) slot-coupled MIMO antenna with an novel artificial magnetic conductor (AMC) reflector for Vehicle-to-Everything (V2X) technology. The proposed antenna comprises two layers separated by an air gap: the upper layer includes the dual-element slot-integrated MIMO antenna with microstrip-line feeds and defected ground structures (I-shaped slots) for coupling reduction, while the lower layer integrates an 8 × 8 array of AMC units. The AMC enhances gain and improves radiation properties through its reflective behavior. Measured results confirm the antenna's suitability for V2X applications, achieving a wide return loss bandwidth (RLBW) of 32% (4.72 - 6.61 GHz), axial ratio bandwidth (ARBW) of 21.18% (5.2 - 6.45 GHz), and isolation greater than 19 dB. The antenna attains a peak gain of 8.6 dBic at 5.9 GHz, with an envelope correlation coefficient below 0.003 and diversity gain exceeding 9.98 dB. The key innovation of this work lies in the combination of CP slot-integrated MIMO design with a novel AMC structure to enhance gain and isolation, making it highly effective for V2X wireless networks in modern vehicular communication networks.
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Broadband unidirectional twin-element MIMO antenna scheme for mid-band 5G and WLAN laptops
(2024-12-01)
Luadang, Bancha
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Janpangngern, Pisit
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Pookkapund, Khanet
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Dentri, Sitthichai
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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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Metasurface-based Circularly Polarized Dual-Port MIMO Antenna for C-band Uplink Applications
(2022-01-01)
Supreeyatitikul, Nathapat
;
Boonpoonga, Akkarat
;
Phongcharoenpanich, Chuwong
The rectangular-shaped metasurface (MTS)- based circularly polarized (CP) dual-port MIMO antenna was proposed. The proposed rectangular-shaped MTS-based CP dual-port MIMO antenna included two substrate layers (upper and lower). The periodic 4×4 rectangular-shaped MTS elements on the upper layer functioned as CP polarizers. Also, the lower substrate layer comprised the microstrip probe feed and ground plane which generated a linearly polarized (LP) wave. The proposed rectangular-shaped MTS-based CP dual-port MIMO antenna at 5.3 GHz achieved impedance bandwidth (IBW) of 30.9% (4.86 - 6.5 GHz) and axial ratio (ARBW) of 14% (5.16 - 5.9 GHz). The maximum gain was 7.3 dBi at 5.1 GHz. The ECC was lower than 0.002, and DG was greater than 9.98 dB between entire frequency ranges. The direction of the radiation was right-hand circular polarization (RHCP). The dimension of proposed rectangular-shaped MTS-based CP dual-port MIMO antenna was 1.342λ0 × 0.652λ0 × 0.0372λ0.
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Experimental evaluation of received signal using blind channel estimation for RFID system via MIMO antenna
(2014-01-01)
Promkeeree, Theerapat
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Duangsuwan, Sarun
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Promwong, Sathaporn
In this paper, we investigate an evaluation of the received signal by using blind channel estimation for radio frequency identification (RFID) system via multiple input multiple output (MIMO) antenna. This method is based on higher order statistic of the received signal to estimate the ambiguity of MIMO antenna. The advantage of blind channel estimation is shown that to achieve the severe of multipath interference, when employed the zero-forcing (ZF) and the minimum mean square error (MMSE) at the receiver. The measurement result is illustrated that the signal verified and estimated of the received signal have been compared. This technique is a novel of signal processing on designing of RFID reader based on MIMO antenna will be utilized. © 2014 IEEE.

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