Semicircle CSRR With Circular Slot Array Structures for High Level Mutual Coupling Reduction in Mimo Antenna

Abstract

A single semicircle shape Complementary Split Ring Resonator (CSRR) is designed to enhance isolation by suppressing mutual coupling between MIMO antennas. Furthermore, high level of mutual coupling by introducing circular slot in-between patch antennas on a substrate which creates additional coupling path between the patch antennas also opposes the some leakage signals coming back from the opposite coupling path after CSRR is etched from ground plane. The proposed patch antenna dimensions are chosen as 37.26 × 28.13 mm for operating at 2.51 GHz frequency, and the lowcost dielectric material, FR-4 (ε r = 4.4), is chosen as the dielectric substrate with 1.6 mm height. The S parameters of proposed antenna prototype are characterized by using VNA. The measured return loss (S 11) and isolation (S 21) are −23.13 dB & −56.8 dB, respectively. The results show that by introducing semicircle CSRR and circular slot, the structure provides a 33.2 dB improvement in mutual coupling for MIMO antenna. Hence, the proposed structure provides a better isolation between two antennas without affecting antenna performance.

SRR Loaded Compact Tri-Band Mimo Antenna for Wlan/Wimax Applications

“…In order to support the utilization of MIMO orthogonal data streams for increasing the channel capacity of various microwave applications like Wi-Fi, WiMAX, WLAN are proposed in [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25]. Conventional microstrip patch antenna can be used to realize MIMO response by using various isolation techniques which are discussed in [10][11][12][13]. A three-folds fork-shaped stub is introduced in the ground plane to improve the isolation [10].…”

“…A mushroom based EBG and a fractal-based structure are used between the two antenna designs to improve the isolation [12]. Metamaterial based CSRR semicircles are introduced in the ground plane for the reduction of mutual coupling [13]. The above antenna designs [10][11][12][13] have better isolation in the desired frequencies.…”

“…Metamaterial based CSRR semicircles are introduced in the ground plane for the reduction of mutual coupling [13]. The above antenna designs [10][11][12][13] have better isolation in the desired frequencies. However, they cover only a single resonance frequency band.…”

“…Many of the above designed antennas have covered single frequency bands [10][11][12][13]. The antenna reported in [15] is compact due to the proposed design with wider bandwidth, but it has a low isolation (≈ 10 dB).…”

A Compact Mimo Antenna With Electromagnetic Bandgap Structure for Isolation Enhancement

“…A few simple methods are discussed to reduce the mutual coupling by employing various techniques such as the introduction of a complementary split-ring resonator (CSRR) and deployment of stub structures. However, the above designs work effectively, and they produce/work for a single resonant frequency band [9][10][11][12]. Hence, these structures are most widely used in a MIMO antenna for reducing coupling effects.…”