Antenna For Mobile Handset Applications Research Articles

A Reconfigurable Antenna for LTE/WWAN Mobile Handset Applications

In this letter, a reconfigurable antenna for mobile handset applications is proposed. This antenna mainly consists of a longer strip, a shorter strip, and a p-i-n diode. Coupling is generated at the gap between the longer strip and the shorter strip. Depending on the different states of the p-i-n diode, the degree of coupling between them is controlled, and the fundamental resonant frequency of the proposed antenna is adjusted. As a result, the proposed antenna in the low band covers the LTE700/GSM850/900 bands. The high band is formed by combining higher-order mode of the longer strip and quarter-wavelength mode of the shorter strip to cover the GSM1800/1900/UMTS/LTE2300/2500 bands.

Small‐size adjustable LTE/WWAN coupled‐fed loop antenna for mobile handset applications

ABSTRACTA compact reconfigurable coupled‐fed loop antenna of the mobile handset for multiband long‐term evolution (LTE)/wireless wide area network operation is presented. The antenna volume is 5 × 10 × 30 mm3 only, while the protruded ground has a width of 30 mm for mounting electronic components. The proposed antenna is consisted of a loop strip and a driven strip. Through the driven strip capacitively coupled to the loop strip, the antenna can generate a 0.25‐wavelength loop resonant mode to form the antenna's lower band to cover the GSM850/900 bands (824–960 MHz). The simple driven strip is also an efficient radiator to excite a resonant mode for the antenna's upper band to cover the GSM1800/1900/WCDMA Band1 bands (1710–2170 MHz). Moreover, when the chip inductor connected to the loop strip has been adjusted from 0 to 12 nH, the antenna's lower band can be shifted to lower frequency and cover the LTE Band17 band (704–746 MHz) and the antenna's upper band is not varied. This tunable technique can allow the loop antenna to cover more operating bands without adding the antenna volume. Detailed operating principle and performances of the proposed antenna are discussed in this article. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2687–2691, 2014

A minimized broadband ferrite antenna for mobile handset applications

ABSTRACTThis article presents a compact broadband antenna made of Co2Y hexagonal ferrite (Ba2Co0.5Zn1.5Fe12O22) for GSM/DCS/PCS/UMTS. The proposed antenna has a minimized volume of 25 × 10 × 2 mm3 using a ferrite substrate with = 12.5 (tan = 0.005) and = 4 (tan = 0.15) at 850 MHz. Additionally, a T‐monopole and capacitively coupled strip are used for bandwidth enhancement. The antenna performance is characterized in terms of the reflection coefficient, gain, and radiation pattern. The measured fractional bandwidth at a voltage standing wave ratio ≤3 is 95.7% (823–2178 MHz), and the measured peak gain at the operating frequency bands is −6.67–4.25 dBi. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2279–2282, 2014

A frequency‐reconfigurable antenna for internal mobile handset applications

ABSTRACTIn this article, a frequency‐reconfigurable planar antenna for mobile handset applications that covers the GSM, DCS, PCS, and UMTS bands is presented and studied. The antenna consists of a single continuous loop element with three connections to a printed circuit board through a feeding point and two shorting points. Additionally, a protruded ground plane is printed on the circuit board near the radiating element. Depending on the switching states of the PIN diode, the reconfigurable antenna operates in a planar inverted‐F antenna (PIFA) mode or loop mode. It is found from the measured results that the PIFA mode covers the GSM band, and the loop mode covers the DCS/PCS/UMTS bands. The occupied antenna volume of the proposed design is 27.8 × 10 × 1.6 mm3, which is quite compact as compared to internal mobile handset antennas that have been reported recently. Good radiation pattern characteristics with reasonable gains have been observed over the operating bandwidths. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1366–1371, 2014

Enhanced Loop Structure of NFC Antenna for Mobile Handset Applications

A new structure of an NFC loop antenna for mobile handset applications is proposed. The proposed antenna consists of conventional loop elements and a parasitic loop embedded capacitor to enhance its performance. Although the sintered ferrite sheets with higher relative permeability(μr≈200)have been used to reduce the performance deterioration due to the eddy current on the battery pack of a mobile handset, their costs are high, and they are considerably breakable. In this paper, with the proposed structure, we effectively enhance the performance of an NFC loop antenna by employing the ferrite-polymer composite with lower relative permeability(μr≈55).

RFID Technology and Applications

RFID is emerging as one of most fundamental technologies to Internet of Things due to its attractive features such as good reading ranges, high data rates, and low cost. RFID has achieved a widespread success in various applications, ranging from asset tracking, highway toll collection, supply chain management, animal identification to surveillance systems. Moreover, there has been a wide scope of development in RFID standards, protocols, and middleware. However, a series of challenging issues should be properly addressed before a massive adaptation of RFID technology. In this special issue, we have received 24 paper submissions and accepted 9 papers finally according to the reviewers’ comment and associate editors’ suggestion. These accepted papers include RFID reader antenna design, RFID tag antenna design, RFID passive transponders, tag collision algorithm, and RFID application systems. B. Lee et al. from Kwangwoon University of Korea proposed a novel structure of an NFC loop antenna for mobile handset applications by improving the performance of an NFC loop antenna when a ferrite-polymer composite is attached between the embedded NFC loop antenna and the phone battery. The proposed loop antenna gives better performance than that of a conventional NFC loop antenna. L. X. Zheng et al. from South China University of Technology proposed a compact RFID reader antenna for UHF near-field and far-field operations. The structure of the antenna is a novel folded-dipole loop and is formed by a concentric metal ring with a split. It can provide uniform magnetic near-field distribution and available farfield gain. Y. Yao et al. from Beijing University of Posts and Telecommunications also proposed a novel RFID reader antenna. This antenna was fabricated using indium tin oxide film; thus, it has optically transparent characteristic.This kind of antenna can be used in clothing stores. P. Jankowski-Mihulowicz et al. from Rzeszow University of Technology proposed novel RFID passive transponders with additional energy harvester. They can recover energy from the electromagnetic field of read device and the harvested energy was utilized to supply a microprocessor acquisition block for developed LTCC pressure sensor. C. Wang et al. from Beijing University of Posts and Telecommunications proposed an advanced dynamic framed-slotted ALOHA algorithm based on Bayesian estimation and probability response to solve the tag collision problem of RFID system. The simulation results show that the proposed algorithm has better performance. We sincerely hope that this special issue can further help the readers to understand RFID antenna design and applications and explore the future development of the system.

Small size tuneable printed F-slot antenna for mobile handset applications

In this article, a compact tuneable F-slot monopole antenna for mobile handset applications, covering the DCS, PCS, and UMTS frequency bands, is presented and studied. An F-shaped slot is embedded in a rectangular monopole patch to accommodate the varactor. The tuning is accomplished by applying a lumped capacitor (varactor) across the slot arms of the patch. By varying the capacitance values of loaded capacitor from 0.5 to 3 pF, the antenna is capable of achieving high tuning ranges from 1.70 to 2.15 GHz. The antenna performance is characterized in terms of the reflection coefficient, radiation pattern, and power gain. The predicted and measured results show fairly good agreement and confirm satisfactory impedance bandwidth characteristics and consistent radiation patterns over the tuned frequency range. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:794–802, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26649

A compact broadband MIMO antenna for mobile handset applications

AbstractA compact planar broadband multiple‐input multiple‐output (MIMO) antenna, which has a good performance under MIMO situations with low mutual coupling (<−11 dB) and low correlation coefficient (≤−15 dB) is presented. The antenna operates a very wide band with good impedance matching (S11 <−10 dB), covering the LTE band 33–37 and 39–40. The elements are mounted on the same side of ground plane with the inter‐element space of 32 mm. The total size of the array is compact (50 mm × 67.2 mm × 0.254 mm), suitable for mobile handset applications. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2773–2776, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26386

Compact Heptaband Reconfigurable Loop Antenna for Mobile Handset

In this letter, an internal folded reconfigurable loop antenna for mobile handset applications is designed, built, and tested. Two operating states with different frequencies are obtained by switching the shorting pins of the loop. The bandwidth of the proposed antenna has been increased by adopting a matching bridge. In a compact volume of 60×5×5 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> , the proposed antenna operates in heptaband, including GSM850, GSM900, GPS, DCS, PCS, UMTS, and WLAN, with the return loss lower than 6 dB. The efficiency and gain with the p-i-n diodes with their bias circuit are also measured and analyzed.

Low profile dual-band-balanced handset antenna with dual-arm structure for WLAN application

In this study, a low profile and dual-band-balanced antenna for mobile handset applications, covering the 2.4 and 5 GHz WLAN frequency bands, is investigated and discussed. The antenna is a thin-strip planar dipole, with folded structure, and a dual-arm on each half of the dipole. The performance of the proposed antenna has been analysed and optimised for the two targeted frequency bands. For validation purposes, an antenna prototype was fabricated and tested. The prototype performance is characterised in terms of the antenna reflection coefficient, radiation pattern, power gain and surface current distribution. The predicted and measured results show relatively good agreement, and confirm good impedance bandwidth characteristics and excellent dual-band performance. In addition, the antenna radiation performance is investigated when the antenna is placed in several locations on the human body, using a hybrid computational electromagnetics technique.

Design and Implementation of Internal Multi-Band Folded Monopole Antenna for Mobile Handset Applications

In this paper, we designed and fabricated a multi-band folded monopole antenna for mobile handsets that can be used for multiple services. The proposed antenna, with a small size of 28.060 × 12.665 × 5.035㎣ can provide sufficient bandwidth to cover the GSM900 (Global System for Mobile Communications: 880-960 MHz), DCS (Digital Cellular System: 1710-1880 MHz), K-PCS (Korea-Personal Communication Service: 1750-1870 MHz), Wibro (2300-2390 MHz) and Bluetooth (2400-2483 MHz) bands.

Wideband balanced folded dipole antenna with a dual-arm monopole structure for mobile handsets

In this study, a balanced antenna for mobile handset applications with enhanced bandwidth performance, covering the bands from 1.8 to 2.45 GHz, is investigated. The antenna is a slot planar dipole with folded structure and a dual-arm on each half. The antenna impedance was investigated using a two-port S-parameter method. For the purpose of antenna power gain measurement, a wide bandwidth planar balun was employed to support a balanced feed from an unbalanced source. For validation, a prototype of the proposed antenna was fabricated and tested. The performance of the antenna was then verified in terms of return loss, radiation patterns and power gain. The calculated and measured results show good agreement and the results also confirm good wideband characteristics with low induced current in the ground plane, thus minimising performance variations and SAR.

Compact Dual-band Balanced Handset Antenna for WLAN Application

In this paper, a balanced antenna for mobile handset applications with dual- frequency performance, covering the 2.4GHz and the entire 5GHz WLAN frequency bands, is investigated and discussed. The antenna is a thin-strip planar dipole with folded structure and a dual-arm on each monopole. For validation, the antenna prototype was fabricated and tested. The performance of this balanced antenna was verifled and characterised in terms of the antenna return loss, radiation pattern, power gain and surface current distribution of the proposed antenna. The predicted and measured results show good agreement.

The compact quad‐band PCB embedded antenna for mobile handset applications

AbstractA novel compact PCB printed quad‐band antenna using a composite loop and PIFA structure for mobile phones is presented. The proposed antenna is composed of a meandered loop antenna and PIFA having the merits of the loop antenna and PIFA. The antenna element is printed on the top ungrounded portion (34.5 mm (W) × 17 mm (L)) of a 0.8‐mm thick FR4 substrate of a mobile phone PCB. Despite the low volume and low profile of the antenna structure, it can fulfill the bandwidth requirements of the GSM900, DCS1800, PCS1900, and UMTS2100 systems with sufficiently high efficiency, thus making it a promising antenna candidate for future mobile terminals. The antenna design was carried out using a high‐frequency structure simulator (HFSS) by Ansoft, and the modeling structure of the mobile handsets was obtained with the aid of the commercially available simulation software SEMCAD. The overall radiation pattern is suitable for mobile applications. To demonstrate the proposed design, simulated and measured results are presented and discussed. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1332–1336, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24309

Multi-Band Printed Internal Monopole Antenna for Mobile Handset Applications

An internal multi-band CPW-fed monopole antenna designed for mobile handset applications is proposed. By embedding an open-ended slot and two parallel slits in the ground plane and radiating element, respectively, a triple-band operation measured along VSWR 3 : 1 that is able to cover the wireless applications such as GSM, DCS, PCS, UMTS, WLAN, and WiMAX can be achieved for this antenna. Furthermore, good radiation patterns and stable gain variation are measured over these bands of interest.

Compact dual‐band diversity antenna for mobile handset applications

AbstractA dual band diversity antenna for PCS and WiMAX bands is proposed and designed with compact dimension. The proposed diversity antenna consists of two dual‐band PIFAs arranged front to front with the same structure. With polarization diversity, jointed shorting structure, and suspended line, the proposed antenna gives high radiation efficiency (&gt;50%), high isolation (&gt;15 dB), and low correlation coefficient (ρe &lt; 0.05. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2600–2604, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23759

Design of Multiband Balanced Folded Dipole Antenna Based on a Dual-arm Structure for Mobile Handsets

In this paper, a balanced antenna for mobile handset applications with enhanced bandwidth performance, that covers four bands (GSM1800, GSM1900, UMTS and 2.4-GHz WLAN), is investigated. The antenna is a slot planar dipole with folded structure and a dual-arm on each monopole. A wide bandwidth planar balun is employed to feed the wideband balanced antenna from an unbalanced source. A prototype of the proposed antenna is fabricated and tested. The performance of the antenna is verifled and characterized in terms of return loss, ra- diation patterns and power gain. The calculated and measured results show good agreement and also conflrm good wideband characteristics for the proposed antenna with multiband operation.

Radiation characteristics of a monopole‐type antenna and an inverted‐F antenna for mobile handset applications

AbstractTwo types of wire antennas, a monopole‐type antenna (MTA) and an inverted‐F antenna (IFA), to be internally mounted in a mobile handset, differing only in the presence of a shorting point for the IFA, are proposed, analyzed numerically and experimentally, and compared. Agreement is remarkable between the numerical and experimental analyses for the electromagnetic radiation patterns. Radiation pattern characteristics of the MTA are close to those of the IFA over the frequency range from 3.0 to 3.6 GHz. On the other hand, the resonance frequency and bandwidth are changed by a fraction of 10 and 3%, respectively. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1931–1935, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22612

Multiband internal antenna using two layer shorted patches for mobile handsets

AbstractA compact multiband internal antenna for mobile handset applications is proposed. Multiband operation is realised by two connected patches in the lower frequency band and wide band characteristics in the higher frequency band. The simulated and measured results show that the proposed antenna can effectively cover GSM, GPS, DCS, PCS, UMTS, Bluetooth/WiFi, and SDMB bands. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 176–179, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22077