On the design of UWB circular fractal antenna with notched-band characteristics using W-shape slot

Abstract

This paper presents the design of notched-band antenna with CPW -feed. The notched -band has been achieved by using the W-shape slot in ground plane. The antenna has been simulated using a 3D -Electromagnetic simulator. The experimental results of proposed antenna exhibit ultra wideband characteristics from 2.0 -15.0 GHz except the notched-band frequency from 5.0 -6.0 GHz. The slot is optimized with respect to width, length and position for a detailed study of notched-band characteristics. It is observed that the centre frequency and bandwidth of notched-band depend on the length and width of slot respectively. The experimental radiation patterns of this antenna are omnidirectional in H-plane and bidirectional in E-plane. This antenna can be useful for UWB system, medical imaging and vehicular radar. Index Terms-Monopole antenna, Fractal Geometry, UWB antenna, Notchband, CPW -feed and UWB system I. INTRODUCTIONWith the release of the 3.1 -10.6 GHz band for ultra-wideband (UWB) operation, a variety of typical UWB applications evolved are indoor/outdoor communication systems, ground penetrating and vehicular radars, wall and through-wall imaging, medical imaging and surveillance. Many future modern UWB communication systems will be utilized to transmit /receive the high data rate with low power consumption at short range communication [1][2]. Therefore, the realization of UWB antennas in planar technologies with small size is the primary requirement. The antenna should have omnidirectional radiation patterns throughout the band. In UWB operating band, the WLAN signal is also present which interferes the UWB signal. To stop the interference by external WLAN signal (5.0 to 6.0 GHz), a band notched filter is required. Using a band notched filter separately along with antenna increases the system size as well as system complexity. To overcome this complexity, many researchers have reported antennas with notched-band characteristics using various shapes of slots in ground plane, feed line and on the radiating patch [3][4][5][6][7][8][9][10]. The most common technique in open literature is a slot loading in the radiation patch [3][4][5]. This gives poor cross-polarization characteristics because the distribution of surface electricity is changed. Other designing methods

A 3 – 18 GHz UWB Antenna with modified feed-line

“…The authors of [9] introduced annular slot and round corners into the ground and use a round-edged bowtieshaped conductor. All the UWB antennas presented satisfy the requirement of FCC band [10][11][12][13][14][15][16]. In [17], a circular monopole antenna with tapered feed-line but ground plane on the back side of the radiating element was proposed, which was compact in size and exhibited a bandwidth ranging from 6.5 GHz to 25 GHz.…”

Design of a microstrip fractal patch antenna for UWB applications

“…The allocated frequency for UWB is from 3.1-10. 6 GHz and it mainly provides high data rates with low energy level for short-range communications [11]. The applications are in the fields of WPAN, HIPERLAN, data transmission between PC and peripheral devices, wireless home networking, sensors networks, recently in mobile phones for data sharing [3,11].…”