1：Experimental Design and Method Selection:

The study employs the periodic paperclip-shaped (PPS) structure to suppress mutual coupling between microstrip antenna elements. The design rationale is based on the bandstop characteristic provided by the PPS structure to balance out strong mutual coupling.

2：Sample Selection and Data Sources:

The study uses a 2*1 microstrip antenna array with adjacent patches spacing of 0.1λ. The substrate is FR4 with specific dielectric constant and loss tangent.

3：1λ. The substrate is FR4 with specific dielectric constant and loss tangent. List of Experimental Equipment and Materials:

3. List of Experimental Equipment and Materials: The antenna array and PPS structure are fabricated and measured. The substrate material is FR4 with dielectric constant of 4.4 and loss tangent of 0.

4：4 and loss tangent of Experimental Procedures and Operational Workflow:

02. 4. Experimental Procedures and Operational Workflow: The PPS structure is placed between two narrowly spaced patches to suppress mutual coupling. The performance is evaluated through S-parameters, current distribution, and radiation pattern measurements.

5：Data Analysis Methods:

The study analyzes the mutual coupling reduction, resonant frequency shift, and gain enhancement through simulation and measurement results.