Optimum polarization configuration of planar circular patch MIMO antenna

Multiple Input Multiple Output (MIMO) is a key technology that plays an important role in achieving the 5G requirement due to its capability to increase channel capacity. However, the increase of channel capacity is influenced by several aspects such as mutual coupling. Many methods are done to decrease the mutual coupling effect such as polarization arrangement of the MIMO antennas. This study on the polarization arrangement of a circular patch MIMO antenna at 3.5 GHz was performed. Four elements of the MIMO antenna are arranged with several polarization configurations both in Co-Polarization and Cross-Polarization. Both simulation and measurement results showed that MIMO with Co-Polarization has a slightly wider bandwidth equal to 295.25 MHz compared to Cross-Polarization with a bandwidth of 274.63 MHz, due to better return loss performed by the former. However, from the mutual coupling perspective, it is observed that MIMO with Cross-Polarization can reduce the mutual coupling from -17.6676dB into -22.462 dB compared to Co-Polarization with the same element distance.Multiple Input Multiple Output (MIMO) merupakan teknologi kunci yang memiliki peran penting dalam pencapaian kebutuhan jaringan 5G karena kemampuannya untuk meningkatkan kapasitas kanal. Tetapi, peningkatan kapasitas kanal dipengaruhi oleh beberapa aspek yaitu salah satunya mutual coupling. Beberapa metode yang dilakukan untuk mengurangi efek mutual coupling antara lain susunan polarisasi dari antena MIMO. Penelitian kali ini berfokus kepada susunan polarisasi dari antenna MIMO berbentuk circular patch  dengan frekuensi 3.5 GHz. Empat elemen MIMO disusun dengan beberapa konfigurasi polarisasi yaitu Co-Polarization dan Cross-Polarization. Hasil simulasi dan pengukuran menunjukan bahwa MIMO dengan Co-Polarization memiliki pita yang lebih lebar sebesar 295.25 MHz dibandingkan dengan Cross-Polarization dengan lebar pita hanya 274.63 MHz, karena return loss yang lebih baik pada Co-Polarization. Akan tetapi, dari perspektif mutual couping, dapat diamati bahwa MIMO dengan Cross-Polarization dapat mengurangi mutual coupling dari -17.667 dB ke -22.462 dB dibandingkan dengan Co-Polarization dengan jarak elemen yang sam

Eight-Port Tapered-Edged Antenna Array With Symmetrical Slots and Reduced Mutual-Coupling for Next-Generation Wireless and Internet of Things (IoT) Applications

A compact and low-cost eight-port (2x4 configuration) tapered-edged antenna array (TEAA) with symmetrical slots and reduced mutual-coupling is presented in this paper using the inset-feed technique. The 8-port TEAA is designed and simulated using CST microwave studio, fabricated using the flame-resistant (FR4) substrate having a dielectric constant (εr) = 4.3 and thickness (h) = 1.66mm and characterized using Keysight technologies vector network analyzer (VNA). The designed 8-port TEAA operates at the 5.05-5.2GHz frequency band. Various performance design parameters, like return-loss, bandwidth, gain, 2D/3D radiation patterns, surface current distributions, and isolation-loss, are briefly studied, and the results are summarized. The eight-port TEAA has featured the bandwidth/ gain characteristic of 195MHz/10.25dB, 3dB beam-width of 52.8o, and excellent mutual-coupling (high isolation-loss) of less than -20dB, respectively. The 8-port TEAA is proposed and characterized to work for next-generation high-throughput WLANs like IEEE 802.11ax (WiFi-6E), Internet-of-Things (IoT), and the upcoming 5G wireless communication systems

Circuit Modeling of Dual Band MIMO Diversity Antenna for LTE and X-Band Applications

This paper presents a study on developing a dual-band antenna equivalent circuit model for X-Band and LTE applications. MIMO antennas play a crucial role in modern wireless communication systems, and understanding their impedance behavior is essential. This work proposes a dual-band lumped equivalent circuit model, utilizing gradient optimization based on antenna-simulated S-parameters in Advanced Design System (ADS). The four radiating elements of the MIMO antenna are accurately modeled, considering their geometry and the defected ground structure (DGS) effect, which enhances the antenna's isolation and low correlation coefficient (ECC). The calculated lumped equivalent circuit model is validated through rigorous simulation and measurement data, demonstrating consistency with the expected results. The experimental measurements show measured isolation exceeding 20 dB while achieving a maximum realized gain of 5.9 dBi and an efficiency of 87%. The developed model holds promise for improving the design and performance of MIMO antennas for various applications