In this paper a wideband multi-input multi-output (MIMO) antenna system for WiFi-LTE wireless access point (WAP) application is proposed. The MIMO antenna system consists of two common element microstrip-fed monopole antennas with dual polarization. Physically closed integration of MIMO antenna elements requires a special technique to increase the isolation between the antennas. A novel structure of parasitic element is introduced to improve the isolation between the antennas. The proposed MIMO antenna system is simulated and optimized using CST Microwave Studio. The designed antenna system is fabricated and measured to verify the simulation results. Reflection coefficient of less than −10 dB and isolation more than 15 dB are achieved in the operating frequency range of 2.3–2.9 GHz which covers WiFi 2.4 GHz and LTE 2.6 GHz bands. The proposed system also provides dual polarization with 10 dB polarization diversity gain and envelope correlation coefficient less than 0.15. Each individual antenna has a gain of 5.1 dB and 68% efficiency.

This research work presents a microstrip-fed antenna that is small, low-profile, planar, and suitable for WLAN/WiMAX and partially ultra-wideband (UWB) applications. The radiating element of the proposed antenna consists of rectangular-shaped ring embedded with a three inverted “S”-shaped and inverted “C”-shaped strips. This antenna is capable of generating penta bands having good impedance matching with wideband characteristics. Prototype of the proposed antenna has been designed, simulated, fabricated, and tested. The overall small size of the antenna is 24.75 mm × 27.39 mm × 1.6 mm with volumetric size of 1 cm3. To understand the characteristics of the proposed antenna, the parametric studies are being performed. The return loss of the proposed antenna shows fair agreement with the simulated and measured results.