Ultra-Compact Reconfigurable Band Reject UWB MIMO Antenna with Four Radiators

Muhammad Saeed Khan,Sajid Mehmood Asif,Adnan Iftikhar,Raed M Shubair,Antonio-Daniele Capobianco,Dimitris E Anagnostou,Benjamin D Braaten

doi:10.3390/electronics9040584

Abstract

A compact reconfigurable UWB MIMO antenna with four radiators that accomplish on-demand band rejection from 4.9 to 6.3 GHz is presented. An LC stub is connected to the ground plane by activating the PIN diode for each radiator. Two radiators are placed perpendicular to each other to exploit the polarization diversity on a compact 25 × 50 mm 2 FR4 laminate. Two additional radiators are then fixed obliquely on the same laminate (without increasing size) in angular configuration at ±45 ∘ perpendicular to the first two planar radiators still exploiting polarization diversity. The design is validated by prototyping and comparing the results with the simulated ones. On demand band rejection through the use of PIN diodes, wide impedance matching (2–12 GHz), high isolation amongst the radiators, compactness achieved by angular placement of the radiators, low gain variation over the entire bandwidth, band rejection control achieved by adjusting the gap between stub and ground plane, and low TARC values makes the proposed design very suitable for commercial handheld devices (i.e., Huawei E5785 and Netgear 815S housings). The proposed configuration of the UWB MIMO radiators has been investigated first time as per authors’ knowledge.

Highlights

For the present and future wireless technologies, Wireless Personal Area Networks (WPANs), Ultra-wideband (UWB), and Multiple Input Multiple Output (MIMO) antennas are fundamental and indispensable transducers
The work presented in [11,12,13] highlights the use of stubs for Wireless Local Area Networks (WLAN) band rejection along with the exploitation of polarization diversity for isolation enhancement amongst the elements
A four element UWB MIMO antenna with a complex band stop design for the WLAN band resulted in an overall footprint of 39.8 × 50 mm2 [18], whereas a similar placement of four element

Summary

Introduction

For the present and future wireless technologies, Wireless Personal Area Networks (WPANs), Ultra-wideband (UWB), and Multiple Input Multiple Output (MIMO) antennas are fundamental and indispensable transducers These transducers enhance MIMO system performance using antenna diversity techniques, such as spatial diversity, pattern diversity, or polarization diversity. The incorporation of λ/2 open stubs on the antenna having ground plane size of 55 × 86.5 mm successfully achieved a notched band; the use of large reflectors restrict further size reduction of the antenna reported in [10]. The work presented in [11,12,13] highlights the use of stubs for WLAN band rejection along with the exploitation of polarization diversity for isolation enhancement amongst the elements. A four element UWB MIMO antenna with a complex band stop design for the WLAN band resulted in an overall footprint of 39.8 × 50 mm2 [18], whereas a similar placement of four element

Objectives

Methods

Results

Conclusion