Table 1.
Comparison of our proposed method with other decoupling approaches.
| Ref. | Decoupling Approach | Frequency Bands (GHz) | Array Application |
Antenna Element Separation (mm) | Reflection Coefficient (dB) | Coupling Reduction (dB) | Main Lobe Gain Enhancement (dB) |
|---|---|---|---|---|---|---|---|
| [22] | Cloaking (Circular Cloaks) |
LF 1: 3.07 HF 2: 3.33 |
Not addressed | 10 | LF 1: −12 (C 3) −17 (Dc 4) HF 2: −11.5 (C 3) −16 (Dc 4) |
Not addressed | LF 1: ~2 HF 2: ~1.5 (Gain pattern restored) |
| [25] | Cloaking (Elliptical Cloaks) |
LF 1: 3 HF 2: 3.33 |
Not addressed | 16 | LF 1: −19 (C 3) −20 (Dc 4) HF 2: −12 (C 3) −21 (Dc 4) |
LF 1: ~25.5 HF 2: ~29.5 |
LF 1: ~1 HF 2: ~1 (Gain pattern restored) |
| [26] | Cloaking (Circular Cloaks) |
LF 1: 0.92 HF 2: 3.2 |
Not addressed | 36 | At LF 1: −14 At HF 2: −20 |
Not addressed | At HF 2: ~5 (Gain pattern restored) |
| [27] | Cloaking (Elliptical Cloaks) |
LF 1: 4.5 HF 2: 5.5 |
Possible but not addressed | 3 | LF 1: −18 (C 3) −30 (Dc 4) HF 2: −12 (C 3) −30 (Dc 4) |
LF 1: ~20 HF 2: ~20 |
LF 1: ~1.32 HF 2: ~3 (Gain pattern restored) |
| [29] | Cloaking (Circular Cloaks) |
LF 1: 0.79–0.86 HF 2: 1.9–2.2 |
Not addressed | ~36.3 | LF 1: −25 (C 3) −18 (Dc 4) HF 2: −8 (C 3) −17.5 (Dc 4) |
At HF 2: ~10 | At HF 2: ~2–3 (Gain pattern restored) |
| [30] | Cloaking (Circular Cloaks) |
LF 1: 0.69–0.96 HF 2: 1.71–2.71 |
LF 1 antenna placed over 2 × 3 HF 2 array | ~20 | Not addressed | Not addressed | For HF 2 array: ~4 |
| [37] | C-PDDN 5 | LF 1: 2.3–2.4 HF 2: 2.4–2.48 |
Possible but not addressed | 96.5 | LF 1: −20 (C 3) −40 (Dc 4) HF 2: −15 (C 3) −20 (Dc 4) |
LF 1: ~21 HF 2: ~21 |
Not addressed |
| [38] | FSS 6 Radiator | LF 1: 1.8–2.7 HF 2: 3.3–3.8 |
LF 1 antenna placed over 2 × 2 HF 2 array | ~25 | At LF 1: −22.5 (Dc 4) For HF 2 array: −27.5 (Dc 4) |
At LF 1: ~25 At HF 2: ~21 |
Gain enhancement not addressed. Peak gain: At LF 1: ~7 For HF 2 array: ~9 |
| [40] | Slot Loading | LF 1: 0.69–0.96 HF 2: 1.7–2.4 |
LF 1 antenna placed over 2 × 2 HF 2 array | ~33 | At LF 1: −25 (Dc 4) For HF 2 array: −30 (Dc 4) |
At LF 1: ~30 At HF 2: ~30 |
Gain enhancement not addressed. Peak gain: At LF 1: ~8 For HF 2 array: ~12 |
| [41] | 2.5 D Cloak Loading | LF 1: 1.64–2.56 HF 2: 4.4–5.0 |
LF 1 antenna placed over HF 2 array | 40 | At LF 1: −25 (Dc 4) For HF 2 array: −20 (Dc 4) |
At LF 1: ~25 At HF 2: ~25 |
Peak gain: At LF 1: ~7 At HF 2: ~7.2 |
| PW 7 | Cloaking (Planar Cloaks) |
LF 1: 4.9 HF 2: 5.2 |
Interleaved array (side-by-side antenna placement) | 2 | LF 1 array:>−10 (C 3) ~−15 (Dc 4) HF 2 array:>−10 (C 3) ~−12 (Dc 4) |
At LF 1 array:~12.5 At HF 2 array:~12.5 |
At LF 1 array: ~3.2 At HF 2 array: ~8.3 (gain pattern for each array is restored) |
| PW 7 | Cloaking (Planar Cloaks) |
LF 1: 4.5 HF 2: 4.7 |
Interleaved array (side-by-side antenna placement) | 1.5 | LF 1 array:−12 (C 3) −20 (Dc 4) HF 2 array:−11 (C 3) −18 (Dc 4) |
At LF 1 array: ~8 At HF 2 array: ~12 |
At LF 1 array: ~3.7 At HF 2 array: ~6.8 (gain pattern for each array is restored) |
1 Lower frequency, 2 higher frequency, 3 coupled, 4 decoupled, 5 cascaded power dividing decoupling network, 6 frequency-selective surface, 7 proposed work.