Adding an Optimisation Search

Add the optimisation search in CADFEKO.

  1. Add an optimisation search. Use the Simplex (Nelder-Mead) method and Low accuracy.
  2. Specify the optimisation parameters.
    1. On the Optimisation parameters dialog, on the Variables tab, define the following variables:
      Variable Min value Max value Start value Grid points
      L0 0.15 0.35 0.2375 Empty
      L1 0.15 0.35 0.2265 Empty
      L2 0.15 0.35 0.22 Empty
      L3 0.15 0.35 0.22 Empty
      S0 0.1 0.32 0.3 Empty
      S1 0.1 0.32 0.3 Empty
      S2 0.1 0.32 0.3 Empty
    2. On the Constraints tab, define the constraints. The reflector element is required to have a greater length than the director elements.
      • L2 < L0
      • L3 < L0
  3. Create optimisation mask 1 to define the upper boundary for the gain (in dB).
    1. For 0° to 88°: gain < 15 dB
      • The value of 15 dB in the forward direction is selected knowing that this antenna will not be able to achieve 15 dB gain. It will not effect the optimisation.
    2. For 90° to 180°: gain < -7 dB
      • The value of -7 dB will have an effect on the optimisation and determines the size of the back lobes that we are willing to accept.
      • Label: Mask_max
  4. Create optimisation mask 2 to define the lower boundary fro the gain (in dB).
    1. For 0° to 30°: gain > 8 dB
      • The value of 8 dB is selected as the minimum desired main lobe gain.
    2. For 32° to 180°: gain > -40 dB
      • The value of -40 dB outside the main lobe is selected arbitrarily low and will not affect the optimisation.
      • Label: Mask_min
  5. Define two far field goals. Use the H_plane far field request to optimise the vertically polarised gain in dB (10*log[]). The weighting for both goals are equal since both goals are of equal importance.
    • Set the 1st goal to be greater than Mask_min.
    • Set the 2nd goal to be less than Mask_max.