# Mutual Coupling Reduction Between Patch Antennas Using Shorting Pin

## TL;DR

A new method using a shorting pin reduces signal interference between patch antennas, improving performance in wireless communication systems.

## Contribution

A self-decoupling technique using a shorting pin to reduce mutual coupling in patch antennas is introduced.

## Key findings

- A shorting pin alters inductance and phase to create a coupling null between adjacent antennas.
- Mutual coupling was reduced from −22 dB to below −40 dB in a two-element antenna prototype.
- The method works for both adjacent and non-adjacent elements in linear and planar arrays.

## Abstract

A simple self-decoupling approach using only a shorting pin is proposed to effectively reduce mutual coupling in multiple-input multiple-output patch antennas. By loading a shorting pin along the polarization direction on one side of the patch antenna, the equivalent inductance of the corresponding source is altered, thereby changing the initial phase of the slot source. This modification, in conjunction with the path effect, creates a mutual coupling null by counteracting the electric fields at the adjacent patch’s feeding position, achieving a reduced mutual coupling level. The simplicity of this decoupling method enables flexibility in practical applications, facilitating adaptation to diverse packaging environments and substrates. Furthermore, the proposed method effectively suppresses mutual coupling between adjacent and non-adjacent elements in multi-element linear arrays, as well as between elements arranged along E-planes and H-planes in planar arrays. To validate the effectiveness of this self-decoupling technique, a two-element decoupled antenna was fabricated and measured. Experimental results demonstrate a decrease in mutual coupling from −22 dB to below −40 dB across the effective frequency range of 4.809 GHz to 4.984 GHz.