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This paper presents a novel approach for designing a mobile antenna with a Low Specific Absorption Rate (SAR). First, the relationship between the electric field and the SAR value is constructed based on the Poynting Theorem studied in the near-field interaction area. Then, the relationship between the surface current and the magnetic field was examined, establishing a connection between the SAR and the surface current on the ground of the antenna. Next, the interaction mechanism of the radiation fields of the antennas with nearby human tissues was studied using electromagnetic boundary conditions derived from Maxwell’s equations. The approach of reducing the antenna radiated electric field was proposed by directly amending the antenna surface current, thereby reducing the SAR levels in human tissues. Finally, three low-SAR antennas are designed according to the proposed approach. This approach was tested using three different antennas. A 3.6 GHz Planar Inverted-F Antenna (PIFA), 1.8 GHz Meandered Planar Inverted-F Antenna (M-PIFA) and 2.4 GHz M-PIFA. The simulation and measurement results of these low-SAR antennas show good impedance matching in the operating frequency range. The peak values of the 10 g average SAR of these three antennas are reduced by more than 30% without compromising the efficiency, maintaining convenient impedance matching at the operating frequency, and without enlarging the antenna dimensions. The measurement was accomplished using thermal analysis and compared with simulation analysis, which proved the validity of this approach as a guide for low-SAR mobile phone antenna design.

This paper proposes an eight-element dual-band multiple-input multiple-output (MIMO) antenna that operates in the fifth generation (5G), n78 (3400–3600 MHz), and WLAN (5275–5850 MHz) bands to accommodate the usage scenarios of 5G mobile phones. The eight antenna elements are printed on two long frames, which significantly reduce the usage of the internal space of the mobile phone. Each antenna element is printed on both surfaces of one frame, which consists of a radiator on the internal surface and a defected ground plane on the outer surface. The radiator is a rectangular ring fed by a 50 Ω microstrip line which is printed on the top surface of the system board. A parasitic unit is printed on the outer surface of each frame, which is composed of an inverted H-shaped and four L-shaped patches. Each parasitic unit is connected to the internal surface of the frames through a via, and then it is connected to a 1.5 mm wide microstrip line on the top surface of the system board, which is connected to the ground plane on the bottom surface of the system board by a via. Four L-shaped slots, four rectangular slots, and four U-shaped slots are etched onto the system board, which provides good isolation between the antenna elements. Two merged rectangular rings are printed on the center of each frame, which improves the isolation further. The return loss is better than 6 dB, and the isolation between the units is better than 15 dB in the required working frequency bands. In addition, the use of a defected ground structure not only makes the antenna element obtain better isolation but also improves the overall working efficiency. The measurement results show that the proposed MIMO antenna structure can be an ideal solution for 5G and WLAN applications. [ABSTRACT FROM AUTHOR]

A novel end-fire wide-scanning metasurface antenna array for a millimeter wave operating at 28 GHz is proposed in this paper. The suggested antenna is considered as a low-cost device since it is printed on both sides of a single-layer FR-4 substrate with a thickness of 0.5 mm and a size of 44×13 mm2. On the top side of the cell phone PCB, eight Yagi antenna elements fed by microstrip lines have been used to form a linear array. The antenna gain and impedance matching are increased by placing a 5×5 metasurface composed of metallic H-shapes right in front of the Yagi array. This technique achieves a large bandwidth of 3.5 GHz from 26.2 to 29.7 GHz, and a high gain of 15.5 dBi, which is almost stable over a wide scanning angle. Finally, in order to understand the integration impact, the proposed antenna phased array has been covered by a casing. The simulation result demonstrates that there is no degradation effect for the entire assembly. [ABSTRACT FROM AUTHOR]

This paper proposes an eight-element dual-band multiple-input multiple-output (MIMO) antenna that operates in the fifth generation (5G), n78 (3400–3600 MHz), and WLAN (5275–5850 MHz) bands to accommodate the usage scenarios of 5G mobile phones. The eight antenna elements are printed on two long frames, which significantly reduce the usage of the internal space of the mobile phone. Each antenna element is printed on both surfaces of one frame, which consists of a radiator on the internal surface and a defected ground plane on the outer surface. The radiator is a rectangular ring fed by a 50 Ω microstrip line which is printed on the top surface of the system board. A parasitic unit is printed on the outer surface of each frame, which is composed of an inverted H-shaped and four L-shaped patches. Each parasitic unit is connected to the internal surface of the frames through a via, and then it is connected to a 1.5 mm wide microstrip line on the top surface of the system board, which is connected to the ground plane on the bottom surface of the system board by a via. Four L-shaped slots, four rectangular slots, and four U-shaped slots are etched onto the system board, which provides good isolation between the antenna elements. Two merged rectangular rings are printed on the center of each frame, which improves the isolation further. The return loss is better than 6 dB, and the isolation between the units is better than 15 dB in the required working frequency bands. In addition, the use of a defected ground structure not only makes the antenna element obtain better isolation but also improves the overall working efficiency. The measurement results show that the proposed MIMO antenna structure can be an ideal solution for 5G and WLAN applications.

In this paper, an effective method for developing a multi-feed multiple-input multiple-output (MIMO) antenna system using the metal rims of a mobile phone without any structural interruption on the long edge frames is proposed. Instead of traditionally designing MIMO antennas with multiple similar antenna structures on the mobile phone frame or its ground plane, the MIMO antennas in this work are realized by reasonably constructing feeding points and grounding points on the entire edge frame. The MIMO antenna system established by such multi-feed technique is capable to achieve much simpler structural configuration, excellent isolation and matching performance while multiple antennas are connected. A planar eight-port MIMO antenna system operating in the 5G frequency band of 3.4~3.6 GHz is investigated initially, and subsequently applied to the curved metal-rims which comply with the industry design of a modern flagship mobile phone. The prototypes are fabricated and measured, evaluation results show that isolations among all ports are better than 15 dB with reflection coefficients below −10 dB within the band of 3.4~3.7 GHz and −6 dB within the band of 3.3~3.8 GHz. In addition, more than 57% total efficiency and envelope correlation coefficient (ECC) of less than 0.3 are obtained. The satisfactory performance reveals the proposed design of multi-feed MIMO antennas can be a promising candidate for 5G metal-rimmed mobile phone applications.

In previously published papers about the metal-frame smartphone antennas, the screen is usually not included in the antenna model. As the big-screen, or even full-screen (also called all-screen or bezel-less) smartphones become the trend in recent and foreseeable future years, the effect of the very close screen to metal-frame antennas becomes prominent, e.g., the antenna's bandwidth is significantly narrowed. In this paper, a metal-frame antenna for the big-screen smartphone covering 824-960 MHz (GSM850/900), 1452-1496 MHz (LTE1500), 1710-2690 MHz (DCS, PCS, UMTS2100, LTE2300/2500), and 3400-3600 MHz (3.5 GHz 5G) is introduced. For the first time, the screen is fully considered, even designed as part of the antenna. The theory of characteristic modes (TCM) is applied in the design method. A prototype is made and measured for verifying the proposed methodology. Some key parameters of this antenna design are also discussed. This methodology helps to improve the degraded performance of smartphone antennas due to the big-screen industrial design.

A nona‐band narrow‐frame antenna with a defected ground structure for mobile phone applications is presented in this article. From the analysis of the structure, the coupled‐fed antenna mainly consists of four parts: bending feeding strip, coupling shorted strip, copper plate and defected ground structure. It can effectively cover LTE700/GSM850/GSM900/DCS1800/PCS1900/UMTS2100/LTE2300/LTE2500 and the ninth band on 3300‐4200 MHz (including LTE3500), which may be applied to the future 5G. The size of the nona‐band antenna is 80 × 7.5 × 5 mm3, and the defected ground structure is only 55 × 0.5 mm2. This structure effectively widens the bandwidth of the low‐frequency band and realizes 2G/3G/4G and possible coverage of the 5G operating band without loading the lumped elements. Thus, it is suitable for smartphone application. A prototype of the proposed antenna is manufactured and measured. The measured −6 dB impedance band‐widths in the low, mid and high bands are 340 MHz (630‐970 MHz), 1410 MHz (1510‐2920 MHz) and 1060 MHz (3160‐4220 MHz), respectively. In addition, the efficiency of the antenna is greater than 60% in most of the working frequency bands, and the antenna has good radiation performances. [ABSTRACT FROM AUTHOR]

A very compact wireless local area network (WLAN) antenna is presented for the design of hand‐held mobile devices. The antenna does not need metal clearance underneath the antenna and it has very low profile. Both simulated and measured results show that the antennas with very small antenna volume and height can operate as a triple‐band WLAN antenna with good bandwidth and radiation efficiency. [ABSTRACT FROM AUTHOR]

A small-size reconfigurable loop antenna for mobile phone applications with a compact volume of 55 × 5 × 3 mm3 is proposed. In addition to the traditional three loop antenna modes, namely, 0.5-λ, 1-λ, and 1.5-λ modes, the proposed loop antenna also generates another 2-λ mode. To cover more operating bands with such compact antenna volume, the reconfigurable technique is therefore applied by inserting an RF switch at the end of the proposed antenna to improve bandwidth at the low band. By combining the four working states of RF switch, the proposed antenna can cover GSM850/900, DCS1800, PCS1900, UMTS2100, and LTE2300/2500 bands with low specific absorption rate and high efficiencies.

A MIMO antenna with 10 elements operating on 3.3‐3.6 GHz for 5G applications is proposed. The 10 elements of the proposed MIMO antenna include six monopoles and four slots with coupled feed. The monopoles and slots are alternately placed along the four sides of the mobile terminal with different radiating modes. The antenna is printed on a planar substrate, resulting in low cost and easy fabrication. The antenna is simulated, fabricated, and measured, the isolations are better than 11 dB, the efficiencies are about 50‐76%. The envelop correlation coefficient (ECC) is lower than 0.15 between any two antenna elements, and the calculated channel capacity is reached about 48‐51 bps/Hz, which is 7 bps/Hz lower than the ideal 10 × 10 MIMO channel. [ABSTRACT FROM AUTHOR]

An antenna with a small nonground portion (56 × 5 mm2) for 5.7 in octa-band mobile phones is presented in this letter. Owing to the stair-like ground branch, the width of the nonground portion is 5 mm (0.013 λg at frequency 0.8 GHz), and the area of ground clearance is only 280 mm2. By utilizing the space with a small value of the electric field, the antenna's size can be reduced without worsening the performance. The optimized structure can generate the high band that covers GSM1800, GSM1900, UMTS, LTE2300, and LTE2500 bands (1710–2690 MHz). Moreover, a double-resonant mode is generated in the low band for LTE700, GSM850, and GSM900 bands (704–960 MHz). A prototype is fabricated, and the measured −6 dB impedance bandwidths are 310 MHz (690–1000 MHz) and 1270 MHz (1680–2950 MHz). Meanwhile, the measured patterns, efficiencies, and gains are also obtained. This antenna is promising to utilize in the future. [ABSTRACT FROM AUTHOR]

Abstract: A novel multifrequency mobile phone antenna with circularly polarized Global Position System (GPS) application is presented in this research. The antenna is composed of a gradient T‐type feedline and a ring‐metal patch with 4 different branches. Specifically, T‐shaped feedline and the ring‐metal patch are contributed to resonate in 1300 MHz‐1900 MHz. Meanwhile, the phase difference generated by the four branches of varying lengths, the antenna produces circular polarization at 1575 MHz. The etching slot in the patch can make the antenna work in 2400 MHz–2700 MHz. The experimental results verify the simulations. The designed antenna can be covered in Global System for Mobile Communications/Digital Communication System/GPS/Long Term Evolution/Wireless Local Area Network/Worldwide Interoperability for Microwave Access and other system operating frequency bands, which is suitable for the current multisystem mobile phone. [ABSTRACT FROM AUTHOR]

In this paper, we designed and implemented a PIFA(Planar Inverted F Antenna) + IFA(Inverted F Antenna) hybrid MIMO(Multi Input Multi Output) antenna for the hexa mobile communication service band. By the simultaneous operation both PIFA and IFA using the coupled feeding structure, we tried for application to modern mobile phones that have large ground size. A PIFA is applied to the ground area, and an IFA is applied to no ground small space on top of the phone. A diagonal fed MIMO antenna is implemented PCB embedded type without antenna carrier component. Implemented antenna on the bare board measured within 3 : 1 for VSWR under hexa mobile communication band as CDMA, GSM900, DCS, KPCS, USPCS, and WCDMA. Measured average gains and efficiencies were -5.19~-3.16 dBi and 30.27~48.26 % for the CDMA, GSM900 band, and -9.50~-5.19 dBi and 11.23~30.28 % for the DCS, KPCS, USPCS, WCDMA band. It's shown that studied antenna can be applied to the antenna for the modern mobile phone. [ABSTRACT FROM AUTHOR]

In this paper, a hybrid MIMO antenna for the metal phone with auxiliary slot for 4th generation mobile communication is designed and implemented. Auxiliary slot locates on the rear metal cover of the phone, and handles for LTE class 40 band. The auxiliary slot operates hybrid with a monopole antenna. Studied antenna satisfies under VSWR 3:1 for LTE class 13/ LTE class 14/ CDMA/ GSM/ DCS/ PCS/ W-CDMA/ LTE class 40 bands. ECC(Envelope Correlation Coefficient) value for MIMO characteristic is less than 0.2 over the whole design bands. Average gains and antenna efficiencies measured by MTG anechoic chamber were -5.57~-1.45 dBi and 27.75~71.6 %, respectively. [ABSTRACT FROM AUTHOR]

Nowadays, more attention has been placed on the chassis modes of electrically small antennas. Besides the antenna radiating element itself, the chassis (ground plane) also has non-negligible contribution to the performance of the antenna system. Properly exciting chassis modes can effectively expand antenna’s working bandwidth and improve its radiation efficiency. In this paper, a novel approach of exciting chassis modes will be demonstrated numerically and practically. It can be seen that by tuning the ground plane geometry, desired chassis mode is excited and the antenna performance is improved. [ABSTRACT FROM AUTHOR]

A novel design of a multiband monopole mobile phone antenna with circular polarization for GNSS application is presented. The proposed antenna generates four resonant frequencies with branch lines and a shorted parasitic strip to obtain a wide operating band. With the definition of 2.5:1 VSWR, the bandwidth covers several wireless communication systems, including GSM (880 \sim 960 MHz), DCS (1710 \sim 1880 MHz), PCS (1850 \sim 1990 MHz), UMTS (1920 \sim 2170 MHz), WiBro (2300 \sim 2390 MHz) and ISM (2400 \sim 2483 MHz), and also covers GNSS, including COMPASS (1559.052 \sim 1591.788 MHz), GPS (1575.42 \pm 5 MHz), GLONASS (1602 \sim 1615.5 MHz). A tuning stub is added to the ground plane and the feeding strip is mounted 45^\circ at the corner to achieve circular polarization for GNSS application. The 3 dB axial ratio (AR) bandwidth (AR-BW) is obtained from 1540 to 1630 MHz, covering the L1 band of GNSS, including COMPASS, GPS and GLONASS. In the 3 dB axial ratio bandwidth, right hand and left hand circularly polarizations are obtained in different broadside directions, with the peak circularly polarized gain of more than 2.7 dBic. An equivalent circuit network is used to analyze the mechanism of circular polarization. Details of the proposed antenna parameters, including return loss, radiation characteristics, and AR spectrum are presented and discussed. [ABSTRACT FROM PUBLISHER]

A compact multiresonant antenna for octaband LTE/ WWAN operation in the internal smartphone applications is proposed and discussed in this letter.With a small volume of 15×25×4mm 3, the presented antenna comprises two direct feeding strips and a chip-inductor-loaded two-branch shorted strip. The two direct feeding strips can provide two resonant modes at around 1750 and 2650 MHz, and the two-branch shorted strip can generate a double-resonance mode at about 725 and 812 MHz. Moreover, a three-element bandstop matching circuit is designed to generate an additional resonance for bandwidth enhancement of the lower band. Ultimately, up to five resonances are achieved to cover the desired 704-960- and 1710-2690-MHz bands. Simulated and measured results are presented to demonstrate the validity of the proposed antenna. [ABSTRACT FROM AUTHOR]

A compact small-size coupled-fed antenna with two symmetrical printed meandered inductive strips as two distributed inductors for seven-band operation covering the GSM850/900/1800//1900/UMTS2100/LTE2300/2500 bands in the internal mobile handset application is proposed. Wideband operation is achieved by incorporating a feeding strip and two radiating strips of different lengths, which are both disposed on the no-ground board space of the proposed antenna. The desired lower bands of GSM850/900 operation can be achieved by the two radiating strips of different lengths, which provide a quarter-wavelength dual-resonance mode at 810 and 962 MHz. While the feeding strip can provide a quarter-wavelength resonant mode at around 1.78 GHz, and other resonant modes at 2.45 GHz are contributed by the higher-order resonant modes of the two radiating strips, covering the desired upper bands of DCS1800/PCS1900/UMTS2100/LTE2300/2500 operation. In addition, the proposed antenna only occupies a planar size of 15\times 30\ mm^2 and is easily printed on one surface of a FR4 substrate, which makes it suitable for practical mobile applications. Detailed considerations of the design and main parameters are studied in this communication and the proposed antenna is successfully simulated, fabricated, and measured. [ABSTRACT FROM PUBLISHER]

A simple low-profile antenna for octa-band LTE/WWAN operation in the internal mobile phone application is proposed and studied in this article. Consisting of a feeding strip and a coupling strip mainly, the presented antenna can be easily printed on the no-ground area of the top of a FR4 substrate, yet it occupies only a size of 15\times 40\ mm^2 and has a height of 3.5 mm. In this scheme, a chip inductor (L1=20\ nH) is loaded in the long inductive strip, which can form a parallel resonant structure together with the coupling strip section close to the feeding strip. With these presences, a double-resonance mode (\lambda/4 resonant mode) is successfully generated at about 720 and 900 MHz to cover the lower band of LTE700/GSM850/900 (704–960 MHz). While the desired upper band of DCS1800/PCS1900/UMTS2100/LTE2300/2500 (1710–2690 MHz) can be obtained with the help of second two resonant modes, including a high-order \lambda/2 resonant mode at 1800 MHz and a \lambda/4 resonant mode at 2550 MHz. That is to say that those two wide operating bandwidths are achieved to cover all the octa-band LTE/WWAN operation. Good radiation efficiency and antenna gain for frequencies over the desired operating bands is obtained. Detailed design considerations of the proposed antenna are described, and both experimental and simulation results are also presented and discussed. [ABSTRACT FROM PUBLISHER]

In this paper, we begin by presenting a multiband antenna for mobile phone applications operating in GSM, DCS, PCS, UMTS, Bluetooth, and LTE bands. The antenna platform includes the ground plane, the battery, the camera, and other paraphernalia that the mobile phone environment typically comprises. Results show that the platform has a significant effect on the performance of the antenna, both in terms of its bandwidth and the number of its resonance frequencies. In addition, metal rings, frequently used in a mobile phone for mechanical reasons, can also have a significant influence on the performance of the antenna in the phone. Equivalent circuits and current distributions have been derived with the objective of investigating the effects of the metal ring that embrace the mobile phone. We investigate ways in which we can modify the ring so as to restore the desired performance of the antenna, which has been previously designed to operate in the phone environment but without the presence of the ring. We show how we can control the resonances of the ring by using capacitance loading and lower its Q by loading the ring resistively at a number of different strategic locations along the ring. [ABSTRACT FROM PUBLISHER]

A penta-band folded antenna for mobile phone applications is presented.The antenna is comprised of two modified inverted-L monopole radiators with a short grounded transmission line for impedance matching and includes a ground plane printed on FR-4 substrate. The radiators are bonded onto a plastic carrier whose dimensions are 50 × 15 × 4 mm3. The antenna is designed and optimized to generate two separate bands, ranging from (i) 870 to 1010 MHz and (ii) 1710 to 2490 MHz with return loss for both better than 7.5 dB. Thus, the antenna covers five bands useful for mobile phone applications, namely, Global System for Mobile Communications/Digital Communication System/Personal Communication Services/Universal Mobile Telecommunications System/Bluetooth. The design strategy was such that the two separate widebands of interest can be controlled relatively independently. Design considerations for the constructed prototype are discussed. The effects of the ground plane, the mobile phone housing and the human hand on the return loss, and the efficiency of the proposed antenna are also investigated. It is found that the hand grip on the mobile phone has a significant effect on the performance of the antenna, especially its efficiency. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:34-40, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27274 [ABSTRACT FROM AUTHOR]

This article proposes a meandered printed loop antenna for the fourth generation (4G) mobile system applications. Using a coupling strip connected with a 50 Ω microstrip fed-line on front side, the loop antenna on back side is excited and a half wavelength (0.5 λ) resonant mode and its higher modes are successfully resonated. A plane copper strip connected at top of the loop antenna is used to increase the antenna's path and to decrease the lower operation band to cover LTE 700 band. Two 15 nH ceramic chip inductors, which are embedded in the loop antenna, are used to decrease the antenna's 1 and 1.5 λ resonant modes. The 0.5, 1, and 1.5 λ resonant modes get together to form a broad lower operation band (693-1031 MHz) for LTE 700 and GSM 850/900 applications. Beside, the antenna's higher resonant modes are also excited to form a broad higher operation band (1668-2781 MHz) for DCS, PCS, UMTS, LTE 2300, LTE 2500, and WLAN applications. The proposed antenna also has an advantage of small size, which is 114 × 50 mm2 including a loop antenna of 14 × 50 mm2 and a ground plane of 100 × 50 mm2. With the advantages of board band, compact size, low cost, and good performance, the proposed antenna appears to be an optimal candidate for the 4G mobile applications. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2157-2163, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26997 [ABSTRACT FROM AUTHOR]

In this article, a low-profile and wideband antenna for mobile terminal is proposed by using a unique direct feed approach.In particular, the approach consists of a cut, a patch, and two vertical slots. It is found that both the patch and slot play an important rule in improving the impedance bandwidth of the antenna. Antenna prototypes were made and good agreement between the simulation and measurement results were obtained. The measured impedance bandwidth of the antenna at -6 dB level is from 0.78 to 3.95 GHz, which is sufficient to cover most of the current radio systems. In addition, a frequency-notched operation can be easily achieved by opening an extra slot on the ground plane. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2724-2728, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25589 [ABSTRACT FROM AUTHOR]

A simple printed-loop antenna with wideband characteristics is presented for laptop computer applications. The proposed rectangular loop pattern generates four resonant modes below 4 GHz. The excited modes, two unbalance and two balance, are analyzed and discussed. A novel U-shaped tuning element printed on the back side of the circuit board adjusts the resonant modes to cover GSM850/GSM900/DCS/PCS/UMTS/WLAN and WiMAX bands. Using HFSS software, this study conducted a simulation to optimize the antenna design and fabricate a practical structure to investigate its performance and characteristics. This study also measures various antenna parameters to validate the proposed antenna. [ABSTRACT FROM PUBLISHER]

In this article, multi-band antenna covering LTE700/GSM850/GSM900/DCS1800/PCS1900 for mobile terminal is presented.The proposed capacitive feeding antenna is a IFA type antenna and implemented as a PCB embedded antenna (PEA). Broad bandwidth in low-band is achieved using pattern overlapped capacitive feeding. Simulation is conducted to verify broad low-band and multi-band operation using HFSS and experimental results are also presented. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1909–1912, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25338 [ABSTRACT FROM AUTHOR]

This article proposed a design of a monopole antenna with a bent loop slit for GSM900/DCS1800/PCS1900/UMTS applications. The proposed antenna was designed on FR4 substrate and fed by 50 Ω microstrip line. The proposed antenna was first designed a rectangle planar patch to operate at a higher frequency of 1.8 GHz for DCS1800/PCS1900/UMTS applications. Besides, the other operation band of 900 MHz for GSM900 applications has been achieved by inserting a bended slit loop into the rectangle planar patch. Simulated and measured results are shown later. Details of the proposed antenna configuration and experimental results are also discussed. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2453–2458, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24638 [ABSTRACT FROM AUTHOR]

A 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 [ABSTRACT FROM AUTHOR]

A novel printed hybrid loop/monopole slot antenna for quad-band operation in the mobile phone is presented. The proposed hybrid antenna is composed of a meandered loop antenna and a monopole slot antenna, and can generate two wide operating bands centered at about 900 and 1900 MHz to cover GSM850/900/DCS/PCS operation. The hybrid antenna is easily fabricated by bending the meandered loop antenna at low cost, which is connected to and centered at the top edge of the system ground plane where a straight monopole slot is embedded. With quad-band operation obtained, the hybrid antenna, however, occupies a small volume of 5.5 × 6 × 60 mm3 or 1.98 cm3 only inside the mobile phone. A 50-Ω microstrip feedline is used to excite the meandered loop antenna and the monopole slot antenna in series. Detailed results and parametric studies of the proposed hybrid antenna are presented. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 795–801, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23201 [ABSTRACT FROM AUTHOR]

At specific situations, workers need to approach very close to the transmitting base station antennas. In this study, occupational exposure to RF fields from base station antennas was assessed at several rooftops. The measurements were carried out by mapping the power densities around the antennas. The results were compared with the ICNIRP guidelines. The results indicate that the reference levels for workers and the general public may be exceeded in front of the transmitting antenna at distances up to 1 and 2 m, respectively. [ABSTRACT FROM AUTHOR]

A printed compact S-shaped monopole antenna for penta-band mobile phone application is presented. The S-shaped monopole antenna has a uniplanar structure and can be printed on an FR4 substrate of small size 10 × 45 mm2 to achieve a compact configuration. By mounting the antenna above the top edge of the system ground plane of the mobile phone and feeding it using a perpendicular feed, the antenna occupies a small volume in the top portion of the mobile phone. This makes it especially suited for application in the thin mobile phone in which the embedded internal antenna is required to be small in occupied volume and narrow in width. In addition, the antenna can generate two wide operating bands at about 900 and 2000 MHz to cover the GSM850/900 and DCS/PCS/UMTS operation, respectively. Details of the proposed antenna are presented. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 3172–3177, 2007; Published online in Wiley InterScience (www.interscience.wiley.com).DOI 10.1002/mop.22929 [ABSTRACT FROM AUTHOR]

A novel miniaturized printed monopole antenna suitable for cellular handset terminals is presented. A substantial reduction in antenna size was achieved due to the use of the inverted-F antenna concept combined with a capacitive feeding system. The antenna operates in three frequency bands, that is, GSM 1800, PCS 1900, and UMTS, with VSWR ≤2.5. The compactness of the antenna structure allows it to be placed on the top as well as the bottom of a handset. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 399–402, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21362 [ABSTRACT FROM AUTHOR]