S. K. Behera

Hybrid Fractal Shape Planar Monopole Antenna Covering Multiband Wireless Communications With MIMO Implementation for Handheld Mobile Devices

A hybrid fractal shape planar monopole antenna covering multiple wireless communication bands is presented for multiple-input-multiple-output (MIMO) implementation for handheld mobile devices. The proposed structure is the combination of Minkowski island curve and Koch curve fractals. It is placed with edge to edge separation of 0.16λ0 at 1.75 GHz. The T-shape strip is inserted and rectangular slot is etched at top side of ground plane, respectively to improve the impedance matching and isolation between the antennas. A measured impedance matching fractional bandwidths ( S11 ≤ -10 dB) are 14% from 1.65 GHz to 1.9 GHz for the band 1 and 80% from 2.68 GHz to 6.25 GHz for the band 2. Acceptable agreement is obtained between the simulated and measured antenna performance parameters. These characteristics demonstrate that the proposed antenna is an attractive candidate for handheld mobile devices.

Modified Half-Circle fractal antenna using DC Theorem for 2.4/5.2 GHz WLAN application

A new form of modified CPW-fed half circle fractal patch antenna is proposed for dual band 2.4/5.2 GHz Wireless Local Area Network (WLAN) application. The circular shape antenna based on the Descartes Circle (DC) theorem and iteration of self similar design. The -10 dB return loss (VSWR 2∶1) impedance bandwidth in 2.4 GHz band is 28% and it covers the required bandwidth for 2.4 GHz WLAN. The 5.2 GHz resonant mode has impedance bandwidth of 40% covering 5.2/5.5/5.8 GHz WLAN bands. The EM characteristics of the antenna are presented by the current distribution. Proposed antenna maintained good radiation patterns with gain. Detailed design steps and results for the designs are studied and investigated in this paper.

Design of wideband fractal antenna with combination of fractal geometries

A new small size fractal antenna is proposed for the application in wide-band frequency range. It is designed with the combinations of two fractal geometries. The wideband mechanism is explored by investigating the behaviour of the current on the patch. The length and width of Koch and cantor fractal geometries are optimized to achieve a wide bandwidth. The feed circuit is a microstrip line with a matching section over a rectangular ground plane. The measured −10dB reflection bandwidth for frequency range (1.64 GHz to 3.5 GHz) is 72.37%. The EM characteristics of the antenna are presented by surface current distributions. The radiation characteristics and gain of the proposed antenna are also presented and discussed.

Design of hybrid fractal antenna for UWB application

A compact fractal monopole planar antenna with size of 30× 25 mm2 is proposed for ultra wide band (UWB) application. The proposed antenna is designed by combination of Giusepe Peano and Sierpinski Carpet fractal geometries. The feed circuit is a microstrip line with a matching section over a semi-elliptical ground plane. The proposed antenna has an omnidirectional radiation pattern and good gain. The simulated results of return loss, gain and radiation patterns are presented and discussed.

Antipodal Vivaldi antenna UWB antenna with 5.5GHz band-notch characteristics

This paper presents a compact antipodal Vivaldi antenna for UWB allocation with band dispersion characteristics. The main purpose of this design is the reduction of three parameter such as transient distortion, reflection co-efficient & surface wave loss. The proposed antenna has the capability to operate over the bandwidth 3-11GHz at return loss <; -10 dB, except the bandwidth of 5-6GHz for WLAN. By cutting Ω-shaped slot in the radiating patch frequency band notch created. The antenna is successfully designed and simulated, it showing broadband matched impedance, stable gain and radiation pattern over a operating bandwidth.

Modified Fractal Shape Antenna for Wideband Application

A new form of modified microstrip-line feed fractal patch antenna is proposed for wideband application. The fractal shape is based on triangular, modified with circle and iteration of self similar design. The -10 dB return loss (VSWR 2:1) impedance bandwidth is 80% ranging from 2.4-5.6 GHz . The EM characteristics of the antenna are presented by the current distribution. Proposed antenna maintained good radiation pattern with gain. Detailed design steps and study of different parameter are presented in this paper.

Microstrip line-fed modified Sierpinki fractal monopole antenna for dual-wideband applications

A printed monopole antenna with microstrip-fed Sierpinski fractal geometry for dual wideband application is presented. The operating bands are adjusted with the design of modified Sierpinski triangle (radiating patch), ground plane and scale factor used to create a fractal shape. The simulated −10 dB (VSWR 2∶1) reflection bandwidth for first resonant frequency is 60% (1.47 GHz– 2.7 GHz). It covers GPS, DCS-1800, PCS-1800, UMTS, IMT-2000, WiBRO (Wireless Broadband Internet Services) and WLAN bands. For second resonant frequency the band width is 8% (4.991HHz–5.4 GHz) and covers 5.2 GHz WLAN (802.11/ a). The radiation characteristics and gain of the modified Sierpinski fractal antenna are also presented and discussed.

H-shaped slot coupled dual-polarized dielectric resonator antenna for C-band applications

In this paper, a cylindrical dielectric resonator antenna (DRA) excited by two orthogonally placed H-shaped aperture slot is presented with high isolation exceeding 32 dB in C-band. For dual linear polarization, the DRA in its TM110 (HEM11) mode is excited to yield broadside radiation pattern. To confine the slots to the central area of cylindrical DR for TM110 mode, the rectangular shaped slots are molded to H-shaped slots. The co-polarization level in both planes is found to be nearly 30 dB higher than the cross-polarization in broad-side direction. The proposed feed for cylindrical (DRA) has been achieved -10 dB impedance bandwidth of 4.8% for 6.1 to 6.4 GHz. The broadside radiation patterns with nearly same pattern shapes are found to be stable with the gain of 5.2 dB for both ports.

Compact modified Sierpinski fractal monopole antenna for multiband wireless applications

A Sierpinski fractal antenna is proposed for multiband wireless applications. It consists of three-stage Sierpinski fractal geometry as the radiating element. The proposed antenna has compact dimension of 75×89.5×1.5 mm3. The multiband characteristic for a return loss less than 10 dB is achieved. The model is applied to predict the behavior of fractal antenna when the height of the antenna is changed. The proposed antenna is considered a good candidate for Multiband Wireless applications.

Two and four-element wideband Sectoral fractal array antennas with omni-directional radiation patterns

Two-element and four-element sectoral fractal planar monopole antenna arrays for wideband communication applications is investigated. The proposed antenna structure is constructed by means of feeding two and four element omnidirectional Sectoral fractal patch elements with a 3-section 2-way Wilkinson power divider. The peak gain values of two-element and four-element array antennas are almost 3 dB and 6 dB higher than the single-element peak realized gain, respectively.