Design of CPW-Fed Triple-Band Two-Port MIMO Antenna with U- Shaped Slot Isolation Structure for High Isolation

Abstract

A novel U-shaped slot isolation structure is placed between a two-port CPW-Fed rectangular patch antenna to reduce the mutual coupling between them. The isolation structure not only increases the minimum isolation by 5 dB but also, coverts a wideband antenna (2.22–4.86 GHz) into a dual-band (2.1–3.03 GHz and 3.45–4.97 GHz) and also helps in achieving a higher-band (7.15–7.94 GHz) due to better impedance matching. The center-to-center distance between the patch antennas is 0.35 λ0. The isolation structure consists of eight etched U-shaped slots from the metal strip of dimensions 19×41 mm2. The proposed MIMO antenna is useful in 2.4 GHz WLAN, 2.5 GHz WiMAX, as a receiver for all IEEE C-Bands and satellite communication. The prototype has been fabricated on an FR-4 substrate of dimension 90×50×0.8 mm3 having an antenna area of 0.22 $\lambda _0^2$ with a maximum measured gain of 3.5 dB across the operating bands.