A Compact Mimo/Diversity Antenna With Wlan Band-Notch Characteristics for Portable Uwb Applications

Abstract

Abstract-In this paper, a compact multiple-input-multiple-output (MIMO)/diversity antenna with WLAN band notch characteristics, high isolation, and good ECC suitable for portable ultra-wideband (UWB) applications is presented. The proposed antenna has optimized dimensions of 29 mm × 38 mm. The antenna consists of two orthogonal circular monopoles with a 50 Ω microstrip feed line. In addition, to enhance the impedance bandwidth, a fractal slot, created using Minkowski fractal geometry, is introduced into the ground plane, which is located on the other side of the substrate, just below the feed line. Good isolation (≥ 21.5 dB) with a fractional bandwidth up to 220% is achieved between antenna elements by introducing two ground stubs and a rectangular slot in the ground plane. A band-notch characteristic in the WLAN band is obtained by etching an elliptical split-ring resonator (ESRR) in the radiator. Moreover, a diversity performance of the antenna in terms of ECC (< 0.01) and capacity loss (< 0.3 b/s/Hz) is performed. This paper offers, for the first time, a combined effect of fractal geometry and ESRR geometry in an antenna design. Finally, a comparison of the proposed antenna is performed with the UWB MIMO/diversity antennas existing in the literature. These results show the suitability of the presented antenna for portable UWB systems.

A Simple Tri-Band Mimo Antenna Using a Single Ground Stub

“…But the close proximity of the elements lead to pronounced mutual coupling resulting in the performance degradation of the system [2]. Several systems with isolation enhancement techniques including defected ground structures, neutralization line, meta-materials, decoupling strips and extended ground plane have been researched over the years [3][4][5][6][7][8][9]. However, there is a trade-off in the size, bandwidth and design complexity in these mutual coupling reduction techniques.…”

A Very Compact Mimo Antenna With Triple Band-Notch Function for Portable Uwb Systems

“…This can also be done by adding strips or stubs adjacent to the radiator or ground or feed line as discussed in [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28]. Each slot or strip can function as a resonator, and the slot or strip length controls the notch center frequency.…”

“…A number of experiments were done earlier to integrate the single and multiple band-notch functions for UWB systems and hence to mitigate the frequency interference from narrowband systems [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. Methods such as etching λ/4 and λ/2 resonators on the ground [11], introducing split-ring resonator (SRR) slots on radiator [12], incorporating two rectangular strips on the ground plane [13], etching a 1λ slot into radiator [14], slitting λ/4 open-ended L-shaped slots on the radiator elements [15], employing λ/4 and λ/2 resonators [16], and using elliptical SRR on the radiator [17].…”

“…Methods such as etching λ/4 and λ/2 resonators on the ground [11], introducing split-ring resonator (SRR) slots on radiator [12], incorporating two rectangular strips on the ground plane [13], etching a 1λ slot into radiator [14], slitting λ/4 open-ended L-shaped slots on the radiator elements [15], employing λ/4 and λ/2 resonators [16], and using elliptical SRR on the radiator [17]. The proposed antennas in [11][12][13][14][15][16][17] mostly reject WLAN band only.…”

“…Methods such as etching λ/4 and λ/2 resonators on the ground [11], introducing split-ring resonator (SRR) slots on radiator [12], incorporating two rectangular strips on the ground plane [13], etching a 1λ slot into radiator [14], slitting λ/4 open-ended L-shaped slots on the radiator elements [15], employing λ/4 and λ/2 resonators [16], and using elliptical SRR on the radiator [17]. The proposed antennas in [11][12][13][14][15][16][17] mostly reject WLAN band only. Dual band-notched functions for UWB-MIMO antennas can be realized by employing nested C-shaped slots in the patch [18], etching 1λ loop path and 0.25λ slot on radiator [19], introducing strips beneath the patch [20], placing open-ended slot and SRR in the ground [21], placing a parasitic strip and open-ended slot on ground [22], or by loading trident-shape strip on the patch [23].…”