Mobile Phone Antenna Research Articles

Coupled-Fed Antenna with Parasitic Ground Structure for Octa-band WWAN/LTE Narrow-Frame Mobile Phone

In this work, an octa-band narrow-frame mobile phone antenna with the size of 80×7×5.5 mm3 is proposed and studied. The designed antenna adopts coupled-fed technology, which is mainly composed of an F-shaped feeding strip, a coupled bending shorted strip, an upright copper plate and a parasitic ground structure. By introducing the F-shaped feeding strip, the coupled bending shorted strip and the upright copper plate, the working frequency of the antenna can cover the lower band (LTE700/GSM850/GSM900) and part of the upper band. Then, with further use of the parasitic ground structure, the upper band (DCS1800/PCS1900/UMTS2100/LTE2300/LTE2500) can be successfully covered in the proposed antenna. Moreover, in this antenna the non-ground portion height is only 7 mm, showing a fully coverage of 2G/3G/4G operating bands without any matching circuit, and great potential for applications in mobile wireless communication systems. In addition, a prototype of the proposed antenna is fabricated and characterized. From the experimental results, the measured -6 dB impedance bandwidths of the antenna at the lower and upper bands are 305 MHz (660-965 MHz) and 1290 MHz (1630-2920 MHz), respectively. Meanwhile, this antenna shows good radiation characteristics in the operating bands.

Mobile phone antenna-matching study with different finger positions on an inhomogeneous human model

ABSTRACTThe human head and hand being in the near-field zone of a mobile phone antenna can drastically influence the antenna matching with free space. The goal of the presented research is to study this phenomenon on an inhomogeneous human model for different relative positions and distances of hand and fingers when using a mobile phone. The only safety criteria commonly used to estimate RF exposure impact on humans is the specific absorption rate (SAR). Its limits are determined by the Federal Communication Commission (FCC) in the USA and the International Commission on Non-Ionizing Radiation Protection (ICNIRP) in Europe. The maximal values of SAR for a mobile handset are determined for each model by the manufacturer. In this paper, it is shown that the peak values provided by the manufacturers and their understanding may need refinement. It is almost impossible to consider all parameters, such as the dependence of SAR on antenna communication matching, with a variety of shapes and forms and other details during physical measurements or numerical estimation. The premise for such assumptions is based on the analysis of S11 dependency on the exposure scenario and the fact that the Automatic Gain Control (AGC) increases power when the signal strength at the base station drops.

The impact of exposure of diabetic rats to 900 MHz electromagnetic radiation emitted from mobile phone antenna on hepatic oxidative stress

ABSTRACTThe excessive exposure of patients with type 2 diabetes mellitus (T2DM) to electromagnetic radiation (EMR) from mobile phones or their base stations antenna may influence oxidative stress and development of diabetic complications. Here, we investigated the effects of exposing type 2 diabetic rats to EMR of 900 MHz emitted from GSM mobile phone antenna for 24 hours/day over a period of 28 days on hyperglycemia and hepatic oxidative stress. Male Sprague-Dawley rats were divided into 4 groups (12 rats/group): control rats, normal rats exposed to EMR, T2DM rats generated by nicotinamide/streptozotocin administration, and T2DM rats exposed to EMR. Our results showed that the exposure of T2DM rats to EMR nonsignificantly reduced the hyperglycemia and hyperinsulinemia compared to unexposed T2DM rats. The exposure of T2DM rats to EMR for 28 days increased the hepatic levels of MDA and Nrf-2 as well as the activities of superoxide dismutase (SOD) and catalase but decreased phosphorylated Akt-2 (pAkt-2) as compared to unexposed T2DM rats. Therefore, the decrease in the hepatic pAkt-2 in T2DM rats after the exposure to EMR may result in elevated level of hepatic MDA, even though the level of Nrf-2 and the activities of SOD and catalase were increased.Abbreviations: BGL: blood glucose level; EMR: electromagnetic radiation; GSM: global system for mobile communication; H2O2: hydrogen peroxide; LSD: least significance difference; MDA:malondialdehyde; Nrf-2: nuclear factor erythroid 2- related factor 2; PI3K: phosphoinositide-3-kinase; pAkt-2: phosphorylated Akt-2; Akt-2: protein kinase; ROS: reactive oxygen species; SEM: standard error of the mean; STZ: streptozotocin; SOD: superoxide dismutase ; O2−: superoxide radical; CT: threshold cycle; T2DM: type 2 diabetes mellitus

Mobile-Phone Antenna Array with Diamond-Ring Slot Elements for 5G Massive MIMO Systems

A design of mobile-phone antenna array with diamond-ring slot elements is proposed for fifth generation (5G) massive multiple-input/multiple-output (MIMO) systems. The configuration of the design consists of four double-fed diamond-ring slot antenna elements placed at different corners of the mobile-phone printed circuit board (PCB). A low-cost FR-4 dielectric with an overall dimension of 75 × 150 mm2 is used as the design substrate. The antenna elements are fed by 50-Ohm L-shaped microstrip-lines. Due to the orthogonal placement of microstrip feed lines, the diamond-ring slot elements can exhibit the polarization and radiation pattern diversity characteristic. A good impedance bandwidth (S11 ≤ −10 dB) of 3.2–4 GHz has been achieved for each antenna radiator. However, for S11 ≤ −6 dB, this value is 3–4.2 GHz. The proposed design provides the required radiation coverage of 5G smartphones. The performance of the proposed MIMO antenna design is examined using both simulation and experiment. High isolation, high efficiency and sufficient gain-level characteristics have been obtained for the proposed MIMO smartphone antenna. In addition, the calculated total active reflection coefficient (TARC) and envelope correlation coefficient (ECC) of the antenna elements are very low over the whole band of interest which verify the capability of the proposed multi-antenna systems for massive MIMO and diversity applications. Furthermore, the properties of the design in Data-mode/Talk-mode are investigated and presented.

LTE and GPS based Deca Band Printed Antenna for Cellular Mobile Handset Communication Applications

This paper presents novel mobile phone antenna for radiations simultaneously in ten frequency bands for applications of LTE (Long-Term Evolution), GPS (Global Positioning System), GSM (Global System for Mobile Communications), PCS (Public and Commercial Services), DCS (Distributed Control System), UMTS (Universal Mobile Telecommunications System) and WiMAX (Worldwide Interoperability for Microwave Access). The antenna demonstrates novel characteristics for resolving the challenge of simultaneous radiation capabilities for the GSM and GPS applications with frequencies of 850/900 and 1575 MHz respectively, along with resonances at frequency band of 700 MHz for LTE applications, 1800 and 1900 MHz for PCS and DCS applications, 2100 MHz for UMTS applications, 2400 and 2500 MHz for LTE applications and 3300 MHz for WiMAX applications with S11 = - 6 dB matching criteria (VSWR 3:1). The antenna architecture comprises top and bottom copper layers embedded with monopole radiating element, branch line, slots and various stub lines. The desired operating bands are achieved in a compact area with overall dimensions of 0.8x60x120 mm for the height, width and length respectively of the antenna providing suitable platform for mobile handset applications. Omni-directional radiation pattern characteristics are achieved throughout the range of frequencies by designing the proposed antenna in monopole configuration. Proposed antenna is fabricated and results for the surface currents, s-parameters and 3D (Three-Dimensional) gain plots are illustrated for the proof of concept.

Radio Frequency Electromagnetic Fields Exposure Assessment in Indoor Environments: A Review.

Exposure to radiofrequency (RF) electromagnetic fields (EMFs) in indoor environments depends on both outdoor sources such as radio, television and mobile phone antennas and indoor sources, such as mobile phones and wireless communications applications. Establishing the levels of exposure could be challenging due to differences in the approaches used in different studies. The goal of this study is to present an overview of the last ten years research efforts about RF EMF exposure in indoor environments, considering different RF-EMF sources found to cause exposure in indoor environments, different indoor environments and different approaches used to assess the exposure. The highest maximum mean levels of the exposure considering the whole RF-EMF frequency band was found in offices (1.14 V/m) and in public transports (0.97 V/m), while the lowest levels of exposure were observed in homes and apartments, with mean values in the range 0.13–0.43 V/m. The contribution of different RF-EMF sources to the total level of exposure was found to show slightly different patterns among the indoor environments, but this finding has to be considered as a time-dependent picture of the continuous evolving exposure to RF-EMF.

Eight-Band Antenna for Full-Screen Metal Frame LTE Mobile Phones

This paper presents an eight-band antenna for full-screen metal frame LTE mobile phones with a size of 142 mm $\times79$ mm $\times7.5$ mm. The proposed antenna mainly consists of two monopole branches, a match circuit, and two ground branches. The two monopole branches and the match circuit are used to cover the lower band (698–960 MHz) and part of the higher band (1710–2690 MHz). One of the two ground branches is used to cover the other part of the higher band, and the other is mainly used to make the lower band matched. The merit of the proposed antenna is that eight bands can be realized under the conditions of an only 2 mm ground clearance and a metal frame; it is very suitable for full-screen metal frame mobile phones. A prototype is manufactured and measured. The measured −6 dB impedance bandwidths are 300 MHz (665–965 MHz) at the lower band and 1190 MHz (1610–2800 MHz) at the higher band. The LTE700, GSM850, GSM900, DCS, PCS, UMTS, LTE2300, and LTE2500 bands are covered. The measured efficiency is bigger than 42%, so it is practical for mobile phone applications.

Multi-Band Hybrid Mobile Phone Antenna Based on Electromagnetic Coupling

This research presents a multi-band hybrid mobile phone antenna based on electromagnetic coupling, which can be applied to mobile handheld devices, occupying a small board space of 39.7mm×15.6mm on the system circuit board. By adding resonant and coupled branch instead of multi-feed on the traditional bent antenna, this design provides four wide operating bands of 0.772—0.998 GHz, 1.540—1.600 GHz, 1.680—2.270 GHz and 2.300—2.690 GHz with the hybrid feature of planar inverted-F antenna (PIFA), L-shape, U-shape and S-shape structures, which cover nine-band, i.e., GSM850, GSM900, GPS1575, DCS1800, PCS1900, IMT200, LTE2300, LTE2600 and Blue Tooth/Wi-Fi. Ansoft software HFSS is used in this research to make the antenna performance better and the operating principle of the proposed antenna is described in detail. Result of simulation reveals that the maximum gains of these four wide bands are 2.20, −0.99, 4.01 and 4.05 dBi, respectively. Moreover, this research also tests the return loss (S11) of the fabricated antenna with the vector network analyzer and the result is in accordance with the simulation result on the whole. There are four wide resonant frequencies which cover nine-band of wireless wide area network (WWAN), wireless local area network (WLAN) and long term evolution (LTE), when the available bandwidth is better than 6 dBi return loss.

Compact 5G MIMO Mobile Phone Antennas With Tightly Arranged Orthogonal-Mode Pairs

In this communication, the novel compact tightly arranged pairs are employed to form a $4 \times 4$ multiple-input-multiple-output (MIMO) system and an $8 \times 8$ MIMO system operating at 3.4–3.6 GHz for fifth-generation (5G) mobile phones. Each tightly arranged pair is composed of a bent monopole and an edge-fed dipole with a compact size of $7 \times 12$ mm2. The orthogonal-mode method is presented to mitigate the mutual coupling of the tightly arranged pairs without any external decoupling structure. With the help of the orthogonal mode, isolation performances across the desired band of the $4 \times 4$ MIMO system and the $8 \times 8$ MIMO system are better than 20 and 17 dB, respectively, with the elements closely spaced. The measured efficiencies are 51.7%–84.5%/49%–72.9%, and the measured envelope correlation coefficients are less than 0.06/0.07 for the $4 \times 4/ 8 \times 8$ MIMO system. The proposed MIMO systems provide a promising solution to compact 5G MIMO mobile phone antennas with good isolation and diversity performance.

Design of small-size nine-band LTE/WWAN smartphone antenna using defected ground structure

A novel small-size LTE/WWAN smartphone antenna for multi-band operation is proposed and investigated. Defected ground structure (DGS) is used in this antenna. The antenna structure is simple, compact and only occupied a small space of 15 × 28 mm2. It is operates over the frequency ranges, 0.8-0.97 GHz, 1.55-2.84 GHz and 3.22-3.65GHz, and suitable for GNSS/2G/3G/4G/5G (VSWR < 3) mobile phone applications. The antenna consists of dual L-shaped strips, an inverted S-shaped strip and a bent coupled-fed strip. In the meantime the ground is grooved, which changes the distribution current of the antenna, greatly improves the complete coverage of the whole-band, and obviously improves the low-band (824-960 MHz) impedance matching. It is particularly worth mentioning that the coupled-fed strip can provide a 0.2λ resonant mode at 880 MHz which was the usual mobile phone antenna does not have. In addition, detailed simulation, experimental measurement and parametric analysis are presented.

A novel multifrequency mobile phone antenna with circularly polarized GPS application

AbstractA 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.

A compact slot antenna configuration for ultrawideband (UWB) terminals and mobile phones

A novel technique to design a mobile phone antenna by using an ultrawideband (UWB) antenna configuration is proposed. The technique is validated with a novel printed slot antenna configuration. The slot is composed of a circle connected to a trapezoid and fed by means of a 50 Ω microstrip line connected to a patch with similar shape to the slot. An UWB antenna with size of 19 mm × 24 mm and measured −10 dB bandwidth of 2.97-11.32 GHz is developed based on the configuration. When the configuration is applied in a system circuit board of 60 mm × 115 mm to design a mobile phone antenna, the simulated −6 dB bandwidths are 1.0-1.2 GHz and 2.25-15 GHz. To enhance antenna bandwidth, another slot with rectangular shape is etched in the ground plane, and the microstrip line is moved to the center of the circuit board and folded to distribute along the rectangular slot. The measured −6 dB bandwidths of the mobile phone antenna are 0.69-1.09, 1.68-2.75, 3.45-3.52, and 3.62-15 GHz.

E-Shape Patch Antenna For Mobile Phone, S-Band and C-Band Applications

E-Shape Patch Antenna For Mobile Phone, S-Band and C-Band Applications

Antenna design for a smartphone with a full metal casing and a narrow frame

A mobile-phone antenna with a wideband feed structure (WBFS) and an auxiliary structure for a full metal casing and a very narrow frame are proposed. The most highlight of this proposed antenna is that it provides a method to overcome the difficulties of designing a high-performance antenna in a full metal casing with a very narrow frame. The WBFS is designed to have a broadband performance. The total size of the antenna is 6 × 48 mm 2 , and a 6 mm long ground clearance is set on the bottom edge of the system circuit board. The experimental results reveal that a good impendence matching is obtained across the frequency bands of 824-960 and 1710-2690 MHz, and the total efficiency is more than 40%. The antenna maintains a good performance when user's hand(s) is (are) holding it; meanwhile, keeps the specific absorption rate (SAR) under the IEEE Std. C95.1 compliant SAR. In addition, the performance of the proposed antenna in a multi-antenna system is examined. The result shows that the proposed antenna is a good candidate for a multiple-input-multiple-output system.

Next Generation Mobile Phone Antenna and its SAR Investigation

This work presents the design and Specific Absorption Rate (SAR) investigation of Fifth Generation (5G) antenna for future mobile communication networks. The radiating patch is made up of copper material backed by a 0.254 mm thicker Roggers-5880 substrate (N9000 PTFE) having relative permittivity and loss tangent of 22x10-1 and 9x10-4, correspondingly. The antenna resonates at 23 GHz frequency band. The major lobe gain of the single component 5G antenna is 7.16 dB.To meet the gain requirements of 5G mobile communication systems, 1 x 4 element array antenna has been proposed which increases the bore side gain up to 12.6 dB at the desired frequency. The proposed antennas efficiency is 91-94 % with a sufficient amount of driving point impedance bandwidth (S11<- 10 dB), i.e. 600-620 MHz;The SAR of the proposed antenna is analyzed at two different parts of human body, i.e. belly and hand. The SAR is averaged over 10g of tissue. The proposed 1 x 4 element antenna gives lower values of SAR (<2 W/kg) on all parts of human body. The proposed array antenna can be used in 5G mobile handheld devices. All the simulations are carried out using CST MWS. The proposed antenna is suitable contender for 5G mobile communication systems.

OTA Evaluation of Mobile Phone Antenna Performance for VoLTE [Measurements Corner

This article compares the over-the-air (OTA) performance of tradit ional voice service and voice-over LTE (VoLTE). We present the results of the OTA measurements of the antenna performance of 22 mobile phones commonly used over the last two years. VoLTE is a feature included in LTE that allows voice service to be delivered as data flows. Traditional studies on LTE include only data service and, therefore, OTA for data service, which is measured with the phone held in the browsing position only by the hand, whereas VoLTE uses the same data channel but with the device held next to the head by a hand. Traditional studies on voice service include only OTA in voice service. The figures of merit (FoMs) taken into account for ranking the devices were the total radiated power (TRP) and the total isotropic sensitivity (TIS), which are related to the transmitter and receiver antenna performance, respectively. Our investigation includes results for talk mode using left- and right-hand phantoms next to the head to calculate the maximum power radiated by the transmitter. To evaluate the sensitivity of the receiver, we considered the performance in talk mode using a right-hand phantom next to the head as well as in data mode using only the hand phantom.

Comment on "Mobile phone radiofrequency exposure has no effect on DNA double strand breaks (DSB) in human lymphocytes".

I have read with interest the article by Danese et al. entitled “Mobile phone radiofrequency exposure has no effect on DNA double strand breaks (DSB) in human lymphocytes” that is published in the Annals of Translational Medicine (1). Danese et al. in their article have tried to investigate the potential genotoxic effect of mobile phone radiofrequency exposure on human peripheral blood mononuclear cells in vitro. They reported that exposure of human lymphocytes to mobile phone radiation did not significantly affect DNA integrity. Despite its challenging topic, this paper has major shortcomings. Over the past decade, my colleagues and I have studied the health effects of exposure to radiofrequency electromagnetic fields (RF-EMFs) emitted by mobile phones (2-12). The first major shortcoming of this paper comes from this point that the authors have not measured the key factors such as the specific absorption rate (SAR) (13-16) in their blood samples. They even have not provided any information about the SAR level of the mobile phone used in their study or the power density (17,18) at the distance they placed the samples. Interestingly, they have discussed the characteristics of the battery and the dimensions of the mobile phone, while very important factors such as the distance between mobile phone antenna and the samples are entirely forgotten. Moreover, it’s not clear whether the samples were located in the near field of the cell phone antenna or far field.

Solving the 5G Mobile Antenna Puzzle: Assessing Future Directions for the 5G Mobile Antenna Paradigm Shift

Advances in antenna technologies for cellular hand-held devices have been synchronous with the evolution of mobile phones over nearly 40 years. Having gone through four major wireless evolutions [1], [2], starting with the analog-based first generation to the current fourth-generation (4G) mobile broadband, technologies from manufacturers and their wireless network capacities today are advancing at unprecedented rates to meet our unrelenting service demands. These ever-growing demands, driven by exponential growth in wireless data usage around the globe [3], have gone hand in hand with major technological milestones achieved by the antenna design community. For instance, realizing the theory regarding the physical limitation of antennas [4]-[6] was paramount to the elimination of external antennas for mobile phones in the 1990s. This achievement triggered a variety of revolutionary mobile phone designs and the creation of new wireless services, establishing the current cycle of cellular advances and advances in mobile antenna technologies.

Magnetic materials for mobile communication antennas substrate application

In this work, 3Ba0.7Sr0.3O·2CoO·10.8Fe2O3 and Ba2Co2Fe12O22 had been fabricated successfully by conventional ceramic process. Crystallographic structure and electromagnetic properties of two kind of hexagonal ferrite with different sintering temperature were investigated. X-ray Diffraction (XRD), Agilent-N5230A Network Analyzer were used to measure ferrite samples. The mobile phone antenna performance was analysed by HFSS. The results revealed that the main phase of two ferrite samples generated at lower temperature due to additive. The optimized parameters of ferrite are sintering temperature at 1000°C. And to emulate antenna model by HFSS find that Z-type and Y-type ferrite substrate can contribute to antenna frequency shifting, radiation efficiency were affected a little.

Experimental verification of the far-field approximation for a mobile phone antenna

The aim of this study was to verify the validity of the far-field approximation for a mobile phone during a call. Typical models of mobile phones were used to measure the electromagnetic field emitted during a call at various distances from the mobile phone using a selective radiation meter Narda SRM 3000. The near-field and far-field theories were applied to obtained measurements. As a result, the far-field approximation could be applied also at a few centimeters from the mobile phone. Nevertheless, it resulted that the best accuracy of the application of the far-field approximation to mobile phones working is obtained at distances larger than 40 cm, in agreement with the theoretic formulations relative to the condition that the antenna dimension is lesser than the wavelength of microwave radiation used by mobile phone working.