Rowdra Ghatak

A CIRCULAR SHAPED SIERPINSKI CARPET FRACTAL UWB MONOPOLE ANTENNA WITH BAND REJECTION CAPABILITY

A novel planar ultra wideband (UWB) antenna using a second iteration Sierpinski carpet fractal shape with circular boundary is presented in this paper. The antenna covers the frequency band from 3GHz to 12GHz (VSWR • 2). The proposed antenna has a meander shaped slot that renders the capability to reject 5.15{5.825GHz band assigned for IEEE802.11a and HIPERLAN/2. The gain is suppressed very well in the desired WLAN bands. The measured antenna peak gain varies from 1.85dBi to 6dBi within the band. The time domain characteristics show that the antenna is not dispersive. A fabricated prototype is developed with close agreement between simulated and measured resonance as well as radiation characteristics.

Perturbed Sierpinski Carpet Antenna With CPW Feed for IEEE 802.11 a/b WLAN Application

A printed antenna useful for IEEE 802.11 a/b WLAN application is proposed in this letter. The antenna adopts a modified Sierpinski carpet geometry in planar monopole configuration. Design steps to achieve the desired resonance characteristics are discussed. Return loss characteristics suggest that the antenna is also suitable for HiperLAN2 system. The peak realized antenna gain is around 3.2 dBi at the lower band and 4.5 dBi at the higher band.

A CIRCULAR FRACTAL UWB ANTENNA BASED ON DESCARTES CIRCLE THEOREM WITH BAND REJECTION CAPABILITY

A novel planar circular Apollonian fractal shaped UWB monopole antenna with band rejection capability is presented in this paper. The antenna performs satisfactorily in the frequency range 1.8{10.6GHz which gives a wide impedance bandwidth of 142% for VSWR within 2. The proposed antenna has the capability to reject the frequency band 5.125{5.825GHz assigned for IEEE802.11a and HIPERLAN/2. This is achieved by a pair of narrow band resonant L-shaped slots in the CPW ground plane. The antenna exhibits satisfactory omnidirectional radiation characteristics throughout its operating band. The measured peak gain varies from 2dBi to 6dBi in the entire UWB band except the notch band. The performances of time domain characteristic is satisfactory with a group delay variation of 1ns that shows the antenna is non dispersive. To ensure the usefulness of the proposed antenna in pulse communications systems, the correlation between the time-domain transmitting antenna input signal and the receiving antenna output signal is calculated. This antenna can be efiectively used for medical imaging and military radar system along with other common UWB applications.

An UWB antenna using modified Hilbert curve slot for dual band notch characteristics

A printed dual band notched ultra wideband monopole antenna with a single perturbed Hilbert curve slot is presented which exhibits 121% impedance bandwidth. A single modified Hilbert curve slot provides dual band notch characteristics in the range of 3.3–3.7 GHz (WiMAX), 3.7–4.2 GHz (C-Band), and 5.15–5.825 GHz (WLAN) which makes the notch design process simpler than other dual band notched antennas. The gain of the proposed antenna varies from 3 to 4 dBi over its operating frequency range, except at the rejection bands. Suitable radiation characteristics are obtained throughout its operating band. Simulation and measured results of the proposed antenna are in good agreement.

A CPW fed planar monopole band notched UWB antenna with embedded split ring resonators

A novel planar monopole antenna for UWB application is designed using a CPW feed and incorporating band rejection of spurious WLAN and HIPERLAN/2A frequencies with the help of split ring resonators. Parametric study of the proposed antenna is also presented.

A wideband Sierpinski carpet fractal cylindrical dielectric resonator antenna for X-Band application

A wideband Sierpinski carpet fractal patterned embedded DRA is presented in this paper. Antenna design methodology is discussed along with its resonance and radiation characteristics. An impedance bandwidth of 50% is obtained covering the entire X-band with similar radiation pattern throughout the band. The average peak gain within the band is about 5.5 dBi

Design and analysis of fractal based UWB monopole antenna

This paper presents the design and analysis of a planar UWB monopole antenna with impedance steps and fractal slots in the ground plane that contributes to ultra wide band characteristics. Here impedance steps as well as Fractal technique is adopted to improve the bandwidth of the antenna in comparison to its non fractal counterpart. The operating frequency of the proposed antenna is ranging from 2.7GHz to 10.9GHz which provides 120% impedance bandwidth, close to UWB specification. The antenna has omnidirectional radiation characteristics and moderate gain throughout its operating band and can be considered as a good candidate for UWB communications.

Multiple fractal-shaped slots-based UWB antenna with triple-band notch functionality

A planar elliptical shape band-notched UWB antenna with multiple fractal-shaped slots and a Sierpinski fractal curve-shaped ring resonator at the back of the substrate is introduced in this paper. The proposed antenna exhibits a triple-band notch characteristic. Koch fractal slot etched from the radiator is responsible for creating notched band centred at 5.5 GHz for wireless local area network rejection. The Minkowski fractal slots in the ground planes create rejection characteristics at 8.1 GHz to avoid interference with X-band uplink satellite communication systems. The RFID rejection band centred at 6.8 GHz is achieved by using a Sierpinski fractal curve-shaped ring resonator at the back of the substrate. Sierpinski fractal slot of third iteration on the radiator contributes to an impedance bandwidth of 2.8–12 GHz with VSWR < 2 by improving matching at lower frequencies except at three notched bands. The antenna gain varies from 1.5 to 4 dBi over the band. Stable radiation patterns are obtained throughout its operating frequency. The antenna has a compact size of 41 mm × 45 mm.

Design and analysis of a 5.88GHz microstrip phased array antenna for intelligent transport systems

Detection of blind spot area of an intelligent mobile vehicle is presented in this paper. In order to scan the concerning area, a phased array radar is designed. The approach is of two fold. Firstly, microstrip phased array antenna with progressive phased shifter is designed and subsequently, it is optimised for improvement of performance through parametric studies and array distribution using Tchebyscheff polynomial. Index Terms- Microstrip antenna, phased array antenna, intelligent transportation system, Tchebyscheff polynomial.

Dual Band Notched UWB Monopole Antenna Using Embedded Omega Slot and Fractal Shaped Ground Plane

This paper presents the development of an Ultra Wide Band (UWB) monopole antenna with dual band notch characteristics. Modifled crown-square shaped fractal slots in the ground-plane are implemented to enhance the impedance bandwidth to around 58% as compared to conventional square monopole antenna without slots. Impedance bandwidth of the proposed antenna is approximately 114% with Voltage standing wave ratio (VSWR) < 2. In addition to this, two omega-shaped (›) slots have been incorporated in the radiating patch to render band-notch characteristics centered at 5.5GHz band assigned to IEEE802.11a and HIPERLAN/2 as well as X-band for satellite communication centered at 7.5GHz band. Measured antenna gain is stable over the entire UWB region except at the notch bands. Radiation pattern of the antenna show that the proposed antenna exhibits nearly monopole like E plane radiation patterns and omni-directional H plane radiation patterns throughout the band. A fabricated prototype is developed with close agreement between simulated and measured results.