Compact 4 × 4 Proximity Coupled Microstrip Fed UWB Stepped Slot MIMO Antenna Having Triple Band Rejection

Abstract

The presented antenna is a novel highly isolated compact four-element Multiple Input Multiple Output (MIMO) antenna with common ground, which can reject three undesired bands effectively for Ultra-Wideband (UWB) Communication. The overlapping of narrowband communication systems with the UWB spectrum makes radio signals interfere. Therefore, the proposed antenna is designed with triple-band rejection capability. The antenna consists of four feedlines and a common ground surface which acts as the main radiator. The four elements of the antenna are kept orthogonally to exploit polarisation diversity, resulting in high isolation. The presented antenna is having size = 44 × 44 mm2 and printed on FR4 substrate. A spiral slot was introduced in the ground surface which behaves similarly as a band-stop filter (BSF) and rejects the X- band for Uplink Satellite Communication. For rejecting WiMAX and WLAN band, the modified trident shape of the microstrip line is used. Also, Defected Ground Structure (DGS) is used for the isolation (> 23 dB) enhancement. Simulation and measurement results are quite similar. The proposed antenna is used for small handheld communication devices.