DESGIN DEVELOPMENT AND SIGNAL PROCESSING OF 5G MIMO ANTENNA ON TWO DISTINCT SUBSTRATES

Abstract

This article covers the design, development, and signal processing of a 5G mm-wave MIMO antenna. The antenna design is first simulated using CST 18 software and optimized iteratively to meet the requirements. After finalizing the design, a prototype is fabricated and tested in an Anechoic Chamber to measure radiation patterns and gain in a controlled environment. The antenna uses two substrate materials: Rogers RT/Duroid and FR4.  Rogers RT/Duroid offers higher efficiency, gain, and lower loss at high frequencies compared to FR4. The design features a partial ground plane and orthogonal positioning of radiating components to enhance isolation. The antenna is designed to be compact and provide high bandwidth, making it ideal for 5G applications. The isolation between ports is greater than 13 dB for the Rogers RT/Duroid substrates and greater than 16 dB for the FR4 substrates. The antenna design using Rogers RT/Duroid resonates at 20 GHz, while the one using FR4 substrates resonates at 28 GHz. Key performance parameters for both substrates, such as ECC (Envelope Correlation Coefficient), MEG (Mean Effective Gain), DG (Diversity Gain), CCL (Channel Capacity Loss), gain, radiation pattern, total and radiation efficiencies, are compared. For the RT/Duroid design, the ECC is less than 0.007, DG is greater than 9.97, CCL is less than 0.4 bps/Hz, peak gain is 7.5 dB, radiation efficiency ranges from 82% to 88%, and total efficiency ranges from 62% to 82% within the desired frequency band (15–35 GHz). In contrast, the FR4 design shows an ECC of less than 0.006, DG greater than 9.95, CCL less than 0.4 bps/Hz, peak gain of 5.6 dB, radiation efficiency between 40% and 52%, and total efficiency between 35% and 50%.  RT/Duroid has a relative permittivity (εr) of 2.2, loss tangent (tanδ) of 0.0009, and a thickness (t) of 0.8 mm, while FR4 has an εr of 4.3, tanδ of 0.025, and thickness of 1.6 mm. The efficiency, gain, and return loss limitations can be mitigated by carefully selecting the dielectric material.