A Review: Circuit Theory of Microstrip Antennas for Dual-, Multi-, and Ultra-Widebands

In this chapter, a review has been presented on dual-band, multiband, and ultra-wideband (UWB). This review has been classified according to antenna feeding and loading of antennas using slots and notch and coplanar structure. Thereafter a comparison of dual-band, multiband, and ultra-wideband antenna has been presented. The basic geometry of patch antenna has been present along with its equivalent circuit diagram. It has been observed that patch antenna geometry for ultra-wideband is difficult to achieve with normal structure. Ultra-wideband antennas are achieved with two or more techniques; mostly UWB antennas are achieved from coplaner structures

Novel Dual Band Frequency Selective Surface and its Applications on the Gain Improvements of Compact UWB Monopole Antenna

In this work, a highly directional ultra-wideband (UWB) microstrip patch antenna as a single-element is suggested. The proposed antenna’s gain is enhanced with a novel dual-band frequency selective surface (FSS) placed beneath it. The FSS design has a hexagonal structure with meander line inductances and a capacitance-like structure connecting all of the corners to the middle. There is no metallic layer on the other side of the substrate, which shows transmission zeros at 4.95 GHz and 12.7 GHz, and a modified U-shaped monopole antenna is developed. First, the performance characteristics of the antenna and FSS are analyzed from the simulation results, and they are validated experimentally after fabrication, followed by measurement. The compact configuration comprises an antenna loaded with the proposed FSS results S11 less than -10 dB from 3.15 GHz to 22.65 GHz, covering the UWB band together with the X, Ku-band with a bandwidth of 19.5 GHz (151.16% FBW). The antenna’s overall physical dimensions would be 38.8 mm×38.8 mm×25.2 mm (0.407λo×0.407λo×0.265λo), with λo denoting the lowest frequency’s free-space wavelength. The FSS loading results in a 9.9 dBi maximum gain at 10 GHz. The antenna’s small size increases bandwidth, and its high peak gain makes it ideal for use in real-time applications

A Novel Ultra-Wideband Frequency Planar Notch-filter Antenna.

Many research works have emerged for ultra-wideband (UWB) systems. One important issue is the antenna design to cover all frequency bands (3.1–10.6 GHz). In most applications, a reduced compact antenna is needed but with several requirements. In this paper, a novel triangle–semicircular planar monopole UWB antenna is presented with a notch filter to avoid the undesirable interferences in ISM (Industrial, Scientific and Medical) band at 5.3 GHz

Design and Analysis of Integrating Antennas for UWB and Cognitive Radio Applications

The increasing demand for improvement and organization of new services has impact the hard ware design method including radio frequency front end, antennas especially in the portable devices. Hence, novel arrangement that are multimode, multi band, low cost, low profile, and simple to integrate into the highlight compact device are needed. Integrating wideband and narrow band antennas presented for various wireless applications. The integration idea is based on the sharing few areas of the one antenna between the other antennas. In this work different antennas are presented for ultra-wide band and cognitive radio applications. The UWB is a short range radio communication that perform high speed communication with rates more than 100 Mbps. The federal communication committee (FCC) defined the UWB range from 3.1GHz to 10.6 GHz for commercial usage. The challenge is to integrate two antennas in a limited space and provide good isolation exist between the antenna ports. Microstrip antennas integrated with DRA are presented cognitive radio applications. The DRA antennas for UWB applications are presented. The DRA antenna with band notch are presented for WLAN applications. First, a new semicircular- semi hexagon microstrip antenna is integrated with cylindrical DRA is proposed for UWB and cognitive radio applications. The proposed antenna placed on a 39mm×38mm×1.6mm fiber glass rein forced epoxy (FR4) dielectric substrate it covers the frequency range from (2.58 GHz to 14GHz) . The cylindrical DRA is aperture fed used for narrow band application. It covers the frequency range from 10.07GHz to 11.38 GHz. The design provide greatest isolation between the two antenna ports achieved. Dielectric resonator antenna (DRA) are having wider band width, low profile, light weight, low conductor loss, low dissipation loss and wider bandwidth compare microstrip antennas. So the DRA antennas are designed for UWB applications

Passive Components for Ultra-Wide Band (UWB) Applications

UWB technology brings the convenience and mobility of wireless communications to very high-speed interconnects in the home and office due to the precision capabilities combined with the low power. This makes it ideal for certain radio frequency sensitive environments such as hospitals and healthcare as well as radars. UWB intrusion-detection radar is used for detecting through the wall and also used for security with fuse avoidance radar, precision locating and tracking (using distance measurements between radios), and precision time-of-arrival-based localization approaches. The FCC issued a ruling in 2002 that allowed intentional UWB emissions in the frequency range between 3.1 and 10.6 GHz, subject to certain restrictions for the emission power spectrum. Other definitions for ultra-wideband range of frequency are also used such as any device that has 500 MHz bandwidth or fractional bandwidth greater than 25% is considered an UWB enable high data rate to be transferred with a very low power that does not exceed −41.3 dBm

Compact Orthogonal Wideband Printed MIMO Antenna for WiFi/WLAN/LTE Applications

YesThis study presents a wideband multiple-input-multiple-output (MIMO) antenna for Wifi/WLAN/LTE applications. The antenna consists of two triangular patches as the radiating elements placed orthogonally to each other. Two T-slots and a rectangular slot were etched on the ground plane to improve return loss and isolation. The total dimension of the proposed antenna is 30 x 30 mm2. The antenna yields impedance bandwidth of 101.7% between 2.28 GHz up to 7 GHz with a reflection coefficient of < -10 dB, and mutual coupling of < -14 dB. The results including S-Parameters, MIMO characteristics with analysis of envelope correlation coefficient (ECC), total active reflection coefficient (TARC), capacity loss, channel capacity, VSWR, antenna gain and radiation patterns are evaluated. These characteristics indicate that the proposed antenna is suitable for MIMO wireless applications

Design and Analysis of a Planar Monopole Antenna's For UWB Applications

The proposed antennas are intend to utilize between 3 to 12 GHz.It consists of a Microstip patch, substrate and a ground plane. The characteristics of the antenna are mentioned. Microstrip antennas have a narrow bandwidth, so bandwidth enhancement is sometimes demanded for sensible applications. Additionally, applications in contemporary communication systems typically need compact antenna size so as to satisfy the miniaturisation needs of mobile units. Thus, size reduction and bandwidth enhancement have become major prototype issues for sensible applications of microstrip antennas . Microstrip or patch antennas are becoming to be more and more valuable on the grounds that they will be printed specifically onto a board. They’re broadly speaking used as a vicinity of flying machines, satellites, mobile, wireless application wherever size, weight, cost, easy installation, mechanics profile area unit constraints, and low profile like Micro strip antennas is also required. This thesis has the design of Microstrip antennas for wireless applications. Three antennas designed. The first design is a Dual band Microstrip antenna which produces dual band characteristics. The second design is a Wideband Microstrip antenna that has wideband characteristics and the third antenna is a Circular Disc Monopole Antenna for ultra wideband application

UWB Technology

Ultra Wide Band (UWB) technology has attracted increasing interest and there is a growing demand for UWB for several applications and scenarios. The unlicensed use of the UWB spectrum has been regulated by the Federal Communications Commission (FCC) since the early 2000s. The main concern in designing UWB circuits is to consider the assigned bandwidth and the low power permitted for transmission. This makes UWB circuit design a challenging mission in today's community. Various circuit designs and system implementations are published in this book to give the reader a glimpse of the state-of-the-art examples in this field. The book starts at the circuit level design of major UWB elements such as filters, antennas, and amplifiers; and ends with the complete system implementation using such modules

Robust, Efficient and Low Profile Fractal Enabled EBG Incorporated Wearable Antenna for WLAN Standards

A compact, robust Koch fractal combined triangular monopole antenna incorporated with a Sierpinski fractal EBG unit cell array is proposed for integral solutions of wearable devices in WLAN standards. The fractal enabled EBG-Antenna has a modified triangular microstrip that acts as a radiator and a 2X2 array of Sierpinski square EBG unit cells as a reflective surface to enhance the performance also as a shield linking the antenna and human body. The proposed antenna demonstrations and impedance match bandwidth of 32 MHz, a gain of 7.86 dBi, Front to back ratio of 13 dB, Radiation Efficiency of 90.35 % at 2.45 GHz in free space. The EBG-Antenna performs well under different bending conditions and human tissue loading as verified by measurements. The specific absorption rate (SAR) is also evaluated and found within limits as per standards. The computed results accomplished the SAR of 0.302 W/Kg, 0.1423 W/Kg for 1 g, 10 g of tissue, respectively, which demonstrates about a 95 % drop associated with the antenna without EBG. Furthermore, the fractal loading makes the antenna compact; EBG introduced at the underside of the monopole antenna gives a high gain-bandwidth product and disengages the human body and the antenna, making the realized antenna a potential candidate with possible seamless incorporation of specified wearable applications in WLAN standards