Investigation of Planar Isolators for Mutual Coupling Reduction in Two-Dimensional Microstrip Antenna Arrays

Table 2

Comparison of the proposed antenna array against the references.

Isolator	Antenna array	Mutual coupling reduction level (dB)	Gain reduction level (dBi)	Modification with antenna array changing
A double-layer meta-surface superstrate [18]	4 × 4	8	NG	Yes
Array-antenna decoupling surface [19]	2 × 2	5	−0.5	Yes
Metamaterial absorber wall [21]	2 × 2	8	−1.2	Yes
Transmission-line-based decoupling structures [23]	4 × 4	8	−0.6	Yes
H-shaped DGS [24]	2 × 2	13	Not given	Yes
Decoupling ground [25]	2 × 2, 4 × 4	7, 7	0.5	Yes
Decoupling slot-strip array [26]	2 × 2, 4 × 4	10, 2	−0.8	No
Neutral lines [28]	2 × 2	3	Not given	Yes
Artificial dielectric layer and metal pillars [29]	4 × 4	5	Not given	Yes
The proposed isolator	2 × 2, 5 × 5	6, 6	−0.3	No