Quad-Band Millimeter Wave monopole MIMO Antenna Loaded With a Defected Ground Plane For 5G Applications

This paper presents a compact, four-element, Quad-band MIMO patch antenna designed for millimeter-wave (mmWave) applications in the Ka-band (26-40 GHz). The design leverages a monopole-printed antenna with a defected ground plane fabricated on a Rogers RO4003 substrate. The antenna achieves a triple-band -10 dB impedance bandwidth of 27.82-30.81 GHz, 33.8-34.6 GHz, and 35.7-36.4 GHz. Each element exhibits acceptable gain ranging from 5.2 dBi to 6.7 dBi across the operating bands (28 GHz, 30.5 GHz, 34 GHz, and 36 GHz). Following the design and analysis of a single antenna element, a four-port MIMO antenna was realized. Both antenna configurations demonstrate characteristics suitable for mmWave 5G and future wireless applications. The MIMO performance evaluation reveals a remarkably low envelope correlation (ECC) of approximately 10⁻⁴, a diversity gain of about 10 dB across the bands, and a negligible channel capacity loss (CCL) of less than 0.001 bits/s/Hz. These findings validate the proposed MIMO antenna's exceptional potential for mmWave future fifth-generation (5G) wireless communication systems deployments.