Closely-packed UWB MIMO/diversity antenna with different patterns and polarizations for USB dongle applications

A closely-packed ultrawideband (UWB) multiple- input multiple-output (MIMO)/diversity antenna (of two elements) with a size of 25 mm by 40 mm is proposed for USB dongle applications. Wideband isolation can be achieved through the different patterns and polarizations of the two antenna elements. Moreover, the slot that is formed between the monopole and the ground plane of the half slot antenna is conveniently used to further enhance the isolation at the lower frequencies and to provide an additional resonance at one antenna element in order to increase its bandwidth. The underlying mechanisms of the antenna’s wide impedance bandwidth and low mutual coupling are analyzed in detail. Based on the measurement results, the proposed antenna can cover the lower UWB band of 3.1-5.15 GHz, and within the required band, the isolation exceeds 26 dB. The gains and total efficiencies of the two antenna elements are also measured. Furthermore, a chassis mode can be excited when a physical connection is required between the ground planes of the two antenna elements. Without affecting the performance of the half slot element, the monopole can now cover the band of 1.78-3 GHz, apart from the UWB band. The proposed antenna structure is found to provide good MIMO/diversity performance, with very low envelope correlation of less than 0.1 across the UWB band

Design synthesis and miniaturization of multiband and reconfigurable microstrip antenna for future wireless applications

Tese de Doutoramento. Engenharia Electrónica e de Computadores - Telecomunicações. Faculdade de Engenharia. Universidade do Porto. 201

A Power-Efficient Multiband Planar USB Dongle Antenna for Wireless Sensor Networks

Wireless Sensor Networks (WSNs) had been applied in Internet of Things (IoT) and in Industry 4.0. Since a WSN system contains multiple wireless sensor nodes, it is necessary to develop a low-power and multiband wireless communication system that satisfies the specifications of the Federal Communications Commission (FCC) and the Certification European (CE). In a WSN system, many devices are of very small size and can be slipped into a Universal Serial Bus (USB), which is capable of connecting to wireless systems and networks, as well as transferring data. These devices are widely known as USB dongles. This paper develops a planar USB dongle antenna for three frequency bands, namely 2.30–2.69 GHz, 3.40–3.70 GHz, and 5.15–5.85 GHz. This study proposes a novel antenna design that uses four loops to develop the multiband USB dongle. The first and second loops construct the low and intermediate frequency ranges. The third loop resonates the high frequency property, while the fourth loop is used to enhance the bandwidth. The performance and power consumption of the proposed multiband planar USB dongle antenna were significantly improved compared to existing multiband designs

Design of a printed multiband MIMO antenna

A multiband MIMO antenna using planar technology is proposed for next generation mobile communication system. The antenna consists of two symmetrical monopole elements printed in parallel to each other at the upper and lower corners of a printed-circuit board (PCB) with a size 50×110 mm2 which is similar to the side of a mobile phone. The two monopoles have two branch strips to generate two frequency bands. By using a parasitic element in each monopole, a much enhanced bandwidth in the upper band can be obtained. A lumped-impedance network is designed to enhance matching at the input ports for the two antenna elements. Computer simulation is used to study, design and optimize the antenna. Results indicate that the proposed MIMO antenna has a very bandwidth enough to cover the LTE (lower band), DCS1800, PCS1900, UMTS-2100, Wibro Band, 2.4G-WLAN, and Wimax (upper band) systems. To enhance the isolation between the two monopole elements within the desirable frequency bands, a slit is cut in the middle on the PCB ground. The MIMO antenna a very low profile and low cost which makes the design very attractive for mobile phone applications. © 2013 EurAAP.published_or_final_versio

A Novel Dual-Band MIMO Antenna with Lower Correlation Coefficient

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

Design and Fabrication of an Electrically Small Meander Line MIMO Antenna System for Wireless Communication Applications

A multiple-input multiple-output (MIMO) technique has been considered one of the most promising technologies to enhance the performance of wireless communication systems with high-speed transmission rates. A MIMO system utilizing several antenna components is more advantageous than a single-input single-output (SISO) system in terms of increasing channel capacity and reducing transmitting power. Conventional universal serial bus (USB) dongles are attractive for providing plug and- play functionality in mobile communication devices such as laptops. Future wireless USB dongles should be capable of accommodating higher data rates than the current systems owing to the advent of various multimedia services. Up to date, most MIMO antenna systems with more than two antennas are three-dimensional rather than planar. However, the basic problem with the MIMO systems is the requirement of electrically small antennas which usually have several constraints. Hence, these antennas are considered in our project work. In this work the design, optimization, fabrication & testing of electrically small antennas suitable for MIMO (multiple input multiple output) applications are presented. When the transceiver uses more than one antenna, the antennas must be placed at least half of the carrier wavelength apart, in order to transmit/receive uncorrelated signals. We propose an electrically small antenna (ESA) that is based on the meander line antenna structure that operates in the 2.4-2.7 GHz ISM band. The proposed antenna has measured center frequency of 2.50 GHz with 240 MHz bandwidth and total size of antenna is 14.5X26.6 mm. In addition, we present the design of a compact dual element MIMO antenna system for a USB dongle operating in the 2.5-2.7 GHz frequency band. Thedesigned MIMO antenna has the compact size of 26.0 mm×32.0 mm, more than 200 MHz bandwidth.Both simulation and experiment results from the fabricated antennas are presented

Design of Low Profile Multiband USB Dongle Antenna

A dual band F-shaped printed mono-pole antenna (USB dongle) with two meandered strips is proposed and tested. The two strips that resonating at 2.45 GHz and 5.2 GHz have uniform and fixed width of 0.5 mm. A thin layer of 0.8 mm thickness FR4 substrate (permittivity =4.4, loss tangent=0.0245) which is economically cheap is used for the unit fabrication.  The two resonant modes will best support Bluetooth (BT) and WLAN (Wireless Local Area Network) having enough supportive bandwidth which is defined by -10dB reflection coefficient. The proposed unit is low profile, compact and simple to fabricate. The whole unit that has an overall size of (0.8mm x 10 mm x 40 mm) is efficient for having 97% and 94 % total radiation efficiency at both operating frequencies respectively. Through applying different simulation scenarios to the unit such as varying the feeding location and changes in the strips length, it has been revealed that the antennas is sensitive and reactive. The proposed antenna has provided good performance and Omni-directional radiation pattern. Good matching between the simulated and measured reflection coefficient results for the antenna prototype has been achieved

Ultra-compact dual-polarised UWB MIMO antenna with meandered feeding lines

An ultra-compact dual-polarised ultra-wideband multi-input multi-output antenna made with a single-shared-radiating element and two meandered feeding lines are proposed. Miniaturisation is achieved by using a combination of techniques, including a resonant stub connected to the ground through which shorts the excessive coupled energy before it reaches the other port and minimises coupling, slots etched in the radiator that also help minimise mutual coupling, while the meandered lines allow to bring the antenna closer to the greatly reduce the overall size of the antenna. Slots etched in the radiator and the use of a stub connected to the ground through, help to minimise the mutual coupling. The formation of orthogonal surface currents provides the necessary dual polarisation. Simulated and measured results demonstrate the wideband impedance matching, low mutual coupling and low envelope correlation coefficient. This antenna has an extremely compact size (22 7 24.3 mm2, including the ground plane) that makes it an excellent candidate for portable and handheld devices. \ua9 The Institution of Engineering and Technology

Frequency-Reconfigurable MIMO Monopole Antenna with Wide-Continuous Tuning Range

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