Concentrated Ground Plane Booster Antenna Technology for Multiband Operation in Handset Devices

The current demand in the handset antenna field requires multiband antennas due to the existence of multiple communication standards and the emergence of new ones. At the same time, antennas with reduced dimensions are strongly required in order to be easily integrated. In this sense, the paper proposes a compact radiating system that uses two non-resonant elements to properly excite the ground plane to solve the abovementioned shortcomings by minimizing the required Printed Circuit Board (PCB) area while ensuring a multiband performance. These non-resonant elements are called here ground plane boosters since they excite an efficient mode of the ground plane. The proposed radiating system comprises two ground plane boosters of small dimensions of 5 mm x 5 mm x 5 mm. One is in charge of the low frequency region (0.824-0.960 GHz) and the other is in charge of the high frequency region (1.710-2.170 GHz). With the aim of achieving a compact configuration, the two boosters are placed close to each other in a corner of the ground plane of a handset device (concentrated architecture). Several experiments related to the coupling between boosters have been carried out in two different platforms (barphone and smartphone), and the best position and the required matching network are presented. The novel proposal achieves multiband performance at GSM850/900/1800/1900 and UMTS

Mobile-phone antenna design

published_or_final_versio

Mobile-phone antenna design

published_or_final_versio

Balanced antennas for mobile handset applications. Simulation and Measurement of Balanced Antennas for Mobile Handsets, investigating Specific Absorption Rate when operated near the human body, and a Coplanar Waveguide alternative to the Balanced Feed.

The main objectives of this research are to investigate and design low profile antennas for mobile handsets applications using the balanced concept. These antennas are considered to cover a wide range of wireless standards such as: DCS (1710¿1880 MHz), PCS (1850¿1990 MHz), UMTS (1920¿2170 MHz), WLAN (2400¿2500 MHz and 5000 ¿ 5800 MHz) and UWB frequency bands. Various antennas are implemented based on built-in planar dipole with a folded arm structure. The performance of several designed antennas in terms of input return loss, radiation patterns, radiation efficiency and power gain are presented and several remarkable results are obtained. The measurements confirm the theoretical design concept and show reasonable agreement with computations. The stability performance of the proposed antenna is also evaluated by analysing the current distribution on the mobile phone ground plane. The specific absorption rate (SAR) performance of the antenna is also studied experimentally by measuring antenna near field exposure. The measurement results are correlated with the calculated ones. A new dual-band balanced antenna using coplanar waveguide structure is also proposed, discussed and tested; this is intended to eliminate the balanced feed network. The predicted and measured results show good agreement, confirming good impedance bandwidth characteristics and excellent dual-band performance. In addition, a hybrid method to model the human body interaction with a dual band balanced antenna structure covering the 2.4 GHz and 5.2 GHz bands is presented. Results for several test cases of antenna locations on the body are presented and discussed. The near and far fields were incorporated to provide a full understanding of the impact on human tissue. The cumulative distribution function of the radiation efficiency and absorbed power are also evaluated.UK Engineering and Physical Sciences Research Council (EPSRC

Antennas and Arrays for Mobile Platforms -- Direct Broadcast Satellite and Wireless Communication

Flexibility of any proposed communication links is becoming one of the most challenging features. Direct broadcasting satellite services, for example, will be greatly enhanced by providing service-on-the-move. This market is very demanding as it necessitates the development of a low cost, low profile antenna that can be mounted on top of SUVs and minivans, which is capable of continuously tracking the satellite. Another example is the wireless antennas for laptops and smart-phones, where the antennas should fit within an extremely small volume and should be capable of addressing many services over wide frequency range. In this dissertation, both DBS and the wireless antennas are addressed. In these studies, efforts have been concentrated in developing low profile planar antennas, in particular, slot arrays. Travelling wave slotted waveguide arrays have been utilized to minimize the scanning angle range limits due to their inherent beam tilt angle. CNC machines were utilized first to fabricate the early prototypes for sub-array developments. Subsequently, a low cost fabrication technology is adopted to develop a low cost and light weight full array using substrate integrated waveguides (SIWs). The SIW is fully characterized and an excellent equivalent model has been derived to allow easy translation of metallic waveguide components to SIW. Various SIW junctions, transitions, and arrays have been developed for array feed networks including a 64 radiating SIW full array and a 32 radiating SIW array with folded feed. Meanwhile, for the wireless antennas, the utilization of reconfigurable hardware has been introduced to provide the required multi-functionality services and wide frequency coverage. Various reconfigurable antennas were developed and utilized to demonstrate their advantages compared to other design options such as wide-band or multi-band approaches. Both micro-electro-mechanical switches MEMS and PIN diodes have been successfully utilized to switch between the different configurations. The placement, control, and modeling of the switches are also discussed and novel modeling and biasing topologies are introduced. A novel and practical concept of reconfigurable multiband antenna is introduced here too, where advantages of both the multi-band and the reconfigurable antenna structures can be simultaneously achieved while supporting more services

Design and Analysis of Various Handset Antennas with the Aid of HFSS

In this thesis, an attempt is made to present the design of handset antennas, the proposed handset acts as a thin wire model that represents the backbone of the final antenna. The designed antenna parameters are subjected to optimization to fit into the desired frequency bands. Different antenna types are used, such as wire antennas and planar antennas designed using theHFSS.The design of basic antennas for handset applications, experimented with a simple monopole and dipole in a 3-D form. The monopole and dipole used in handset antennas provides multi-band and broadband properties that cover the desired frequency bands in the handset antennas. The design experiment and analysis of a continuous and unbroken metal rimmed antenna with a monopole which is directly fed with a patch acts as aloo antenna in smart phone applications is proposed. The antenna proposed here provides a straight forward and a good multi-band antenna result for anprotected metal rimmed smart phone. The protected rim and two no-ground portions are set on the both the top and bottom sides of the system circuit board, respectively. The system ground is surrounded between the two no ground portions which are connected to the metal rim with a small grounded patch which divides the unbroken metal rim into two strips. Atlast the dualloop antenna is formed by adjusting the ground plane and the micro strip ina proper way. The design antenna is operated on several number of GSM bands.The second design is study of a balanced antenna with folded architecturefor mobile handset applications with dual-frequency performance (2.40 GHzand 5.00 GHz) for WLAN applications are discussed. The thin-strip planardipole is used as an antenna with folded architecture and two arms on eachmonopole. The folded architectures one on the left and other on the rightacts as a dipole and are capable of providing the multiple bands .The antenna performance is featured by using the antenna radiation pattern,returnloss, power gain and surface current distribution of the antenna. The parametric studies are carried out by varying the antenna height and width of1 mm each, the parameters are optimized for steered impedance matchingwithin the range of frequency bands for both the WLAN and short distance communication systems.The third design is focused on the frequency band (1.8 GHz to 2.45 GHz)in which the balanced antenna for applications of mobile handsets with abandwidth of highly improved performance. The slot planar dipole is usedan antenna here with folded architecture and is having a dual arm on boththe sides of the ground plane. The S-parameter method is used to findthe antenna impedance. In order to obtain the power gain measurementin the antenna.The balanced feed from an unbalanced source is supportedby planar balun which is of wide bandwidth to get the desired gain. The results measured provides a good agreement and also provides good wideband characteristic

The design of multi-band planar inverted-F antennas for mobile handsets with the aid of a novel genetic algorithm and their specific absorption rate

Wireless communications have progressed very rapidly in recent years and mobile handsets are becoming smaller and smaller. Present-day mobile cellular communication systems include combinations of the AMPS, GSM-900, DCS-l800, PCS-1900, UMTS, and WLANs in the 2.4GHz and 5.2GHz bands. User requirements for access to the various aforementioned wireless telecommunication services have resulted in a rapid technological push to unify these different systems in a drastically decreased size single mobile handset. All this combined with strict limitations set for the energy absorbed by the users of mobile terminals has created a need for improved antenna solutions and better understanding of small antennas. The objective of this thesis is to develop novel multi-band handset antenna design solutions to satisfy the specific bandwidth requirements of mobile cellular communication systems. [Continues.