optimize

Antenna or array optimization constraints, specified as a cell array of strings or character vectors. Each character vector or string must be of the form: (analysis function) (inequality sign) (value). You can specify any of the following analysis functions:

The inequality signs '<' or '>' and the values specifies the analysis function limits. For example, 'Area < 0.03' indicates that the area of the optimizing antenna must be less than 0.03 square meter.

Example: {'Area<0.03'}

Data Types: char | string

Weight or penalty of each constraint function, specified as a vector of positive integers in the range (1,100). If the penalty is set to high, a higher priority is given to the constraint function in case of multiple constraint optimization. All constraint functions are weighted equally by default.

Example: 8

Data Types: double

Range of frequencies for vector frequency analysis like S-parameters, specified as a vector of positive numbers with each element unit in Hertz.

The default frequency range is obtained from the center frequency considering a bandwidth of less than 10 percent.

Example: linspace(1e9,2e9,10)

Data Types: double

Reference impedance of antenna or array being optimized, specified as a scalar in ohms.

Example: 75

Data Types: double

Azimuth and elevation of main lobe of antenna or array being optimized, specified as a two-element vector with each element unit in degrees. The first element represents azimuth and the second element represents elevation.

Example: [20 30]

Data Types: double

Number of iterations to run the optimizer after you build the model, specified as a positive scalar.

Example: 40

Data Types: double

Use Parallel Computing Toolbox during optimization, specified as either true or false. Use the canUseGPU function to check if dedicated GPU is available for computations and Parallel Computing Toolbox is installed and ready for use.

Example: true

Data Types: logical

Option to enable mutual coupling of elements in an array during optimization, specified as a logical true to enable or false to disable. By default, this option is enabled.

Example: false

Data Types: logical

Option to print iteration number and value of convergence on the command line, specified as a logical true to enable or false to disable. By default, this option is disabled.

Example: true

Data Types: logical

Geometric constraints for optimization, specified as a structure of coefficient matrix and constant vector.

Specify linear inequality constraints in the A matrix and b vector.

For example, consider an optimization problem consisting of 5 design variables as follows:

designVariables = {'CenterArmNotchLength','NotchLength','Width',...
            'CenterArmNotchWidth','NotchWidth'};

Define the A and b as follows:

A = [5,-1,0,0,0;...
     0,0,-1,1,2];
b = [0;0];

Specify linear equality constraints in the Aeq matrix and beq vector.

Specify non-linear inequality constraints in the nlcon matrix and nrlv vector.

For example, to maximize the gain of a dipole antenna operating at 75 MHz with constraints on its length and width, use this code:

optAnt = optimize(dipole, 75e6, "maximizeGain", {"Length", "Width"},... 
  {opt.lb; opt.ub}, Iterations=150, GeomConstraints=opt);
opt = 

  struct with fields:

        A: [100×2 double]
        b: [100×1 double]
      Aeq: [-1 5]
      beq: 0
    nlcon: @btw
     nrlv: [1 1]

For additional information on linear and nonlinear equalities and nonlinear inequalities, see the fmincon (Optimization Toolbox) function documentation.

Example: A=[5,-1,0,0,0; 0,0,-1,1,2]; b=[0;0]; structure.A=A; structure.b=b;

Example: Aeq=[-1 5]; beq=0; structure.Aeq=Aeq; structure.beq=beq;

Example: nlcon=@btw; nrlv=[1 1]; structure.nlcon=nlcon; structure.nrlv=nrlv;

Data Types: struct

Algorithm to use for antenna or array optimization, specified as a string. By default, the optimize function uses SADEA algorithm. Use TR-SADEA for applications where the evaluation of the objective function is computationally expensive. For more information, see optimization algorithms.

Example: UseAlgorithm="TR-SADEA"

Data Types: string