Table 3 Optimization results for Circuits I through IV.
Circuit | Target operating parameters | Actual operating parameters | Geometry parameter values | Computational cost | ||
|---|---|---|---|---|---|---|
Center frequency f0Â [GHz] | Power split ratio KÂ [dB] | Center frequency f0Â [GHz] | Power split ratio KÂ [dB] | |||
I | 1.0 | 0.0 | 1.0 | 0.15 | x* = [0.72 0.62 11.7 15.9 1.37 0.68 0.41 0.35 4.53 0.60]T | 104 |
II | 1.0 | 0.0 | 1.0 | 0.1 | x* = [5.53 14.4 22.0 1.07 0.90 0.85]T | 130 |
III | 2.0 | 0.0 | 2.0 | 0.0 | x* = [1.10 1.01 0.74 0.11 1.23 0.35 6.09 2.02]T | 61 |
IV | 1.2 | 3.0 | 1.2 | 3.0 | x* = [21.7 0.53 0.69 3.86 0.64 23.0 0.22 0.45 0.56 0.55 0.52 0.33]T | 135 |
| Â | Case study | |||||
|---|---|---|---|---|---|---|
Circuit I | Circuit II | Circuit III | Circuit IV | |||
Substrate | AD300 (εr = 2.97, h = 0.76 mm) | RO4003 (εr = 3.38, h = 0.762 mm) | FR4 (εr = 4.4, h = 1.0 mm) | FR4 (εr = 4.4, h = 1.0 mm) | ||
Design parameters | x = [g l1r la lb w1 w2r w3r w4r wa wb]T | x = [l1 l2 l3 d w w1]T | x = [G g1 g2 g3 w1 w3 L1 L2]T | x = [W w1_r w2_r w3 w4 L L1_r L2_r L3 L4 L5_r s]T | ||
Other parameters | L = 2dL + Ls, Ls = 4w1 + 4 g + s + la + lb, W = 2dL + Ws, Ws = 4w1 + 4 g + s + 2wa, l1 = lbl1r, w2 = waw2r, w3 = w3rwa, and w4 = w4rwa, wc = 1.9 mm | d1 = d +|w – w1|, d = 1.0, w0 = 1.7, and l0 = 15 mm | L = 4w1 + 10w3 + 15g3 + 2L2, W = 4w3 + 2L1 + G + 2g1 + 2g3 | - | ||
Target operating frequency | f0 = 1 GHz | f0 = 1 GHz | f0 = 2 GHz | f0 = 1.2 GHz | ||
Target power division ratio | K = 0 dB | K = 0 dB | K = 0 dB | K = 3 dB | ||
Initial design | x(0) = [0.5 0.52 7.0 8.5 0.5 0.4 0.15 0.15 2.0 0.3]T | x(0) = [5.3 13.3 21.5 0.96 0.89 0.90]T | x(0) = [1.0 1.0 0.6 0.25 2.4 0.25 9.0 3.75]T | x(0) = [12.0 0.5 0.8 3.0 2.4 12.0 0.4 0.6 1.2 1.0 0.8 0.51]T | ||
Operating parameter at x(0) | fa.0 = 2.2 GHz K = 1.2 dB | fa.0 = 2.1 GHz K = 0.2 dB | fa.0 = 1.05 GHz K = 1 dB | fa.0 = 2.7 GHz K = 3 dB | ||