Table 1 Comparison of the proposed rat race coupler with existing designs, highlighting operating frequency, harmonic suppression, insertion loss, return loss, isolation, and size reduction.
Reference | Frequency (GHz) | IL21 (dB) | IL31 (dB) | RL (dB) | Isolation (dB) | Size Reduction (%) | Harmonic Suppression |
|---|---|---|---|---|---|---|---|
0.9 | NR* | NR* | 44 | 39 | 69 | 2nd and 4th | |
1 | 3.53 | 3.34 | 30 | 35 | 66 | 2nd to 6th | |
2.4 | 3.52 | 3.65 | 22 | 20 | 55 | 2nd and 3rd | |
1.45 | 3.19 | NR | 20 | 20 | 54 | 3rd and 5th | |
1.5 | 3.25 | 3.37 | 15 | 43 | 57 | None | |
1.8 | 3.2 | 3.2 | 35 | 35 | 74 | 2nd to 7th | |
0.6 | 3.26 | 3.31 | 22 | 30 | 62 | 3rd to 7th | |
3 | 4 | 4 | 18.5 | 20 | None | 2nd | |
2.25 | NR* | NR* | 30 | 20 | 50 | None | |
0.95 | 3.4 | 3.5 | 12 | 45 | 47 | 2nd and 4th | |
2.45 | 4 | 4 | 10 | 20 | 63 | None | |
This Work | 1.4 | 3.2 | 3.3 | 42 | 38 | 70% | 2nd to 10th |
