Mutual Coupling Suppression Between Two Closely Placed Patch Antennas Using Higher-Order Modes

Abstract

This paper presents a novel method for decoupling two patch antennas. Instead of using the TM10 mode of a conventional patch, TM20 mode is utilized as the operation mode of the antenna. By loading stubs at the radiating edge of the patch, the resonance frequency of the TM20 mode is moved down to the same band as the original TM10 mode. Then the mutual coupling between two such patch antennas is suppressed simply by physical placement, even when they are placed extremely close to each other. Without using any extra decoupling elements, isolation is improved by up to 20 dB using this method. Furthermore, this method can also be applied to multi-element multi-input-multi-output (MIMO) array and dual-antenna system with different operating bands. The proposed method is verified with three different application scenarios, including a 2element MIMO array, a 2-antenna system with adjacent operating bands, and a 4-element MIMO array. Reasonable agreements between simulated and measured results can be observed, showing the advantages of simple structure, low cost, high isolation, and good radiation performance. Index Terms-Adjacent band, in-band, mutual coupling, MIMO, patch antenna.

Dual-Linearly Polarized Magneto-Electric Dipole Antenna for In-Band Full-Duplex Applications

“…In contrast to the case of using orthogonal polarisation, obtaining good isolation will be more complicated if the same polarisation for the TX and RX must be preserved. Recently, some works on the co-linearly polarised (co-LP) IBFD antenna have been proposed [9], [10], [11], [12], [13], [14], [15], [16], [17], [18]. Utilising the decoupling resonator is a common method to improve the isolation between the TX and RX [9], [10], [11], [12].…”

“…Moreover, bending the electric-field null [14] and superposing the different modes [15] can also help reduce the coupling between the ports. Furthermore, the reshaped higher-order mode for radiation is beneficial to the decoupling between two closely located radiating elements [16], [17]. Despite providing good isolation, these different methods only consider the single linear polarisation scenario.…”

Quadruplex Slot Antenna for Dual-Standard Operation With Small Frequency Ratio

“…To address the mutual coupling problem, many technologies can be found in the literature such as decoupling networks [1,2], parasitic elements [3,4], neutralization lines [5], surface wave suppression [6,7], and deliberately designed antenna arrangements [8,9]. Unfortunately, most of these techniques are only verified with narrow-band antennas, which may only be effective for some narrow-band applications such as Bluetooth and 2.4GHz WiFi.…”