Table 3 Optimization results for Circuits I through IV.

From: Rapid and reliable re-design of miniaturized microwave passives by means of concurrent parameter scaling and intermittent local tuning

Circuit

Target operating parameters

Actual operating parameters

Geometry parameter values

Computational

cost

Center frequency f0 [GHz]

Power

split ratio K [dB]

Center frequency f0 [GHz]

Power split ratio K [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

 

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