Mutual Coupling Reduction Using Micromachined Complementary Meander-Line Slots for a Patch Array Antenna

This letter presents new microfabricated point symmetric meander-line (ML) slots inserted on the ground plane to reduce mutual coupling between narrowly spaced patches in a 2 × 1 patch array antenna for a WLAN application (4.94-4.99 GHz). The distance between the patches is 2 mm (edge-to-edge space: 0.06 λ
_g
), and the ML slot unit cell has a dimension of 1.37 × 9.62 mm
²
. The resonant frequency mismatch between S11 and S22 caused by the asymmetric structure of a single-ML slot has been mitigated by placing two ML slots in a complementary point symmetric fashion. The ML slots on the ground plane have been fabricated using photolithography and electrodeposition, where the smallest dimension is 160 μm. The fabricated antenna shows a maximum isolation improvement of 34.3 dB and no resonant frequency shift between S11 and S22.