Microstrip Line and CPW Fed Ultra Wideband Slot Antennas With U-Shaped Tuning Stub and Reflector

Abstract

Abstract-Wideband printed rectangular slot antennas backed with reflectors for unidirectional radiation patterns are investigated. A Ushaped tuning stub is used to improve the matching. Two different feeding mechanisms are introduced. A rectangular slot excited by microstrip line feed with a U-shaped tuning stub gives an impedance bandwidth of 110% (|S11| < −10 dB). When the rectangular slot is excited by a coplanar waveguide (CPW), it gives an impedance bandwidth of 120%. Both slot antennas radiate broadside across the matching band, with front-to-back ratios of 20 dB.

Design of Open Slot Antenna for Bandwidth Enhancement With a Rectangular Stub

“…There is an apparent contradiction between the reduced antenna size and wide bandwidth in practice. The sizes of the antennas [1][2][3] having adequate bandwidth are too large for the portable systems, while the bandwidths of the antennas [4,5] with small size are not sufficient for ultra-wideband requirement. Many configurations for bandwidth enhancement in the antenna designs are proposed, such as rectangular aperture [6], multi-via holes [7], fractalshaped slot [8], and multiple resonant slots [9], but the dimensions of these antennas are too large for portable systems.…”

“…In these antenna designs, different geometries are introduced to obtain wide impedance bandwidth, such as a squarering slot [1], E-slot [2], a rectangular notch [3], wide rectangular slot [4], and open L-slot [5]. There is an apparent contradiction between the reduced antenna size and wide bandwidth in practice.…”

“…Recently, wideband slot antennas [1][2][3][4][5][6][7][8][9][10][11][12][13] have received much attention in wireless communication systems, owing to their attractive merits, such as low profile, low cost, easy manufacture, and wide impedance bandwidth.…”

Wideband Co-Planar Microstrip Patch Antenna

“…Majority of these works carried out are based on relatively thick substrates. Indeed, there are many different methods proposed in the literature to tackle the narrow-band width problem, [9][10][11] none of which uses thin substrate to achieve wide bandwidth performance.…”

Design of a Compact Printed Band-Notched Antenna for Ultrawideband Communications

“…Printed monopole antennas can be considered as a good candidate for UWB applications due to their light weight, simple structure, and ease of mass production. In the design of a printed UWB antenna, the radiator and the ground plane shapes as well as the feeding structure can be optimized to achieve a good broad impedance bandwidth [4][5][6][7][8][9][10][11][12]. In addition, time domain analysis of UWB antenna plays an important role to determine pulse distortion of the received signal [13][14][15][16].…”