Abstract
In this chapter, we report the outline of design and optimization of multiband antenna, the ground plane of which is introduced with a Complementary Split Ring Resonator (CSRR).The dimension of CSRR is optimized using a soft-computing tool like Artificial Neural Network (ANN) and evolutionary computing like Genetic Algorithm (GA). The proposed design of the multi-band frequency terminal antenna for high data rate applications is compact with low return loss and multiband in characteristics. The ANN and GA based optimizations improve the design considerably for applications in a range of wireless and mobile communication set-ups including Long Term Evolution-Advanced (LTE-A). The design has inset feed over microstrip line geometry for a frequency of 2.4 GHz. The dimension of the feed line is 7.64×14.89 mm. The microstrip antenna is designed over a FR4 epoxy substrate with dielectric constant,e_r=4.4.
TopIntroduction
In modern wireless and mobile communication, an antenna plays a very significant role in creating the communication link. Withnew developments in communication technology and wireless local area network (WLAN), the wireless standards have experienced rapid evolution. Among these, wide spread popularity has been associated with the IEEE 802.11b/g and IEEE 802.11a/g standards which uses frequencies in the range of 2.4 GHz-2.48 GHz and 5.15 GHz-5.35 GHz or 5.725 GHz-5.825 GHz respectively (Kurniawan & Mukhlishin, 2013). There are other similar slots currently available in which many mobile communication systems are deployed. These are GSM 900/1800/1900 bands (0.890-0.960 GHz and 1.710-1.990 GHz), Universal Mobile Telecommunication Systems (UMTS) and UMTS 3G expansion bands (1.900-2.200 GHz and 2.500-2.700 GHz); and Wi-Fi (Wireless Fidelity)/Wireless Local Area Networks (WLAN) bands (2.400-2.500 GHz and 5.100-5.800 GHz). All these have necessitated the design of compact transmit receive systems including the antenna. For all compact and portable communication equipments there is a necessity to design a single antenna of appropriate shape that can accommodate different frequency bands (Srivastava, V. K. Singh, A. K. Singh, & Ali, 2013; Sahu, & Choudri, 2012; Ali, V. K. Singh, A. K. Singh, & Ayub, 2012; V.K. Singh, Ali, & A. K. Singh, 2011; V.K. Singh, Ali, & A. K. Singh, & Ayub, 2013; Ali, V. K. Singh, A. K. Singh, & Ayub, 2013; Singh et al., 2013).Naturally, multiple frequency slots require multiple antennas which are not always possible. The design trend is to have a single structure which can be used for multiple applications in different frequency ranges. Microstrip patch antenna can eliminate the need for these multiple antennas. So currently in wireless communication applications, microstrip antennas areused extensively and are in demand due to their advantageousphysical properties such as low profile,light weight, low production cost,, reproducibility and ease of fabrication and also easy to integrate with solid state devices and wireless technology instruments and equipments for multi band frequency operation (R. Gupta & N. Gupta, 2006).In modern wireless communication standards, Multiple Input Multiple Output (MIMO) is an important configuration that provides high data rate communication link. MIMO uses additional paths to increase communication link capacity (Nigam & Kumar 2012; C. Garcia-Pardo, J. M. M. Garcia-Pardo, Rodriguez & Llacer, 2013) and optimizes the transmission spectrum and power (Nigam & Kumar 2012; Winters, 1987; Foschini & Gans, 1998). Thus, MIMO system promises a cost effective way to provide higher data rate, higher capacity and a more spectrum efficient wireless communications system. MIMO continues to evolve in several forms and shall be the backbone of the upcoming networks. So in the backdrop of these evolving scenarios, the design of compact, multiband antenna structures has received widespread attention, several designs have established their efficiency though several challenges continue to drive researches in this domain.
The patch antenna suffers from a major problem of narrow bandwidth (Guha & Antar, 2011). The easiest solution to overcome this problem has been to increase the dielectric thickness. A large dielectric thickness, however, leads to poor radiation efficiency and so various other techniques are used to improve bandwidth, including impedance matching networks using stub and negative capacitors/inductors, microstrip slot antennas and inverted slots in the ground plane, surface wave suppressing using magneto-dielectric substrate and electromagnetic band gap (EBG) structures, and composite resonator microstrip antennas using meta material resonator (Akhavan & Syahkal, 1997; H. Kumar, M. Kumar, M. Kumar, A. Kumar & Kanth, 2012; Malik & Kartikeyan, 2012; Sarkar, Saurav& Srivastava, 2013).
Key Terms in this Chapter
WiFi: Wi-Fi is a local area wireless technology. It allows a electronic device to exchange data or connect to the internet. It uses 2.4 GHz UHF and 5 GHz SHF.
Micrstrip: It is a type of electrical transmission line which is used to transmit microwave frequency signal. It consists of a strip line and is seperated from ground plane by a dielectric substrate.
MIMO: Multiple Input Multiple Output (MIMO) is used to improve communication performance by using multiple antennas at both the transmitter and receiver.
Return Loss: Return loss is a power lost of returned or reflected signal by a discontinuity of transmission line. Return loss gives the measure of how well a device is matched. A device is said to be well matched if the return loss is high.
WiMAX: Worldwide Interoperability for Microwave Access (WiMax) is wireless communication standard. It gives data rate of 30-40 megabit per second.
WLAN: A Wireless Local Area Network (WLAN) is a wireless computer network which connects two or more device using a wireless distribution method within a limited area.
VSWR: VSWR gives the measurement that numerically describes how well the antenna is impedence matched to the transmission line.
HFSS: High Frequency Simulator Structure (HFSS) is commercial tool used for antenna design.
GSM: Global System for Mobile Communication(GSM) was developed by European Telecommunications Standards Institute (ETSI). It is a standard which describes the protocols of second generation digital cellular network used by mobile phones.
UMTS: The Universal Mobile Telecommunication System (UMTS) is a third generation mobile cellular system. UMTS is based on GSM standard and developed and maintained by 3GPP (Third Generation Partnership Project).