International Core Journal of Engineering 2020-26 | Page 213

With a diameter of 300mm, UCA with different number
of array elements was simulated for 10 times independently,
and the optimal result was selected under different iteration
times. The parameters were set as follows: initial temperature
was 100, temperature drop ratio was 0.9, and iteration time
was 100. The position angles (in degrees) of the elements
have been shown in table I.
optimization result. The obtained individual
P new  is
compared with the initial population. If the current individual
meets the annealing scheme, a new individual is stored in the
candidate population and retained, continue to step 2. If not,
the individual value of the global optimal solution of the
previous iteration is retained.
4) Setting the lowest temperature and iteration, the
optimal individual P new can be obtained.
TABLE Iκ N = 8~30 T HE POSITION ANGLES ( IN DEGREES ) OF THE ELEMENTS
N
8
9 0
0 36.4
35 -36.2
-35.6 -99
84.4 99.2
-85.2 -126.4
-120 -179.8
154.9 -155.6 11 0 35.6 -35.4 66.1 -66 -93.6 136.3 -136.3 160.5 -160.5 -126.4 143.7 -144.2 179.9
-88.6 -99.6
63.8
-119.2 -48.3
12
21
30
0
24.5
-24.5
64.9
-65.3
-85.4
126.2
0 13.3 -26.2 30 -37.2 -54.9 70 -66.4 84.5
-111 110.3 -121.1 133.8 -141.6 -154.6 167.1 -173.8 -173.8
0 -3.7 15.5 -11.1 24.1 35.1 -39.7 50.2 -59.2
75.1
-109.9 -71.7
123.5 83.7
143.8 -86.9
-179 95
131 -135.7
-169 -155.5 -146.9 -146.9
109
positions obtained by Cornwell algorithm has been shown in
Fig. 2.(a). Element positions obtained by the proposed
method is shown in Fig. 2.(b). It can be seen that a more
optimized array can be obtained by the proposed method.
The objective function value obtained by (1) is 11713, the
objective function value obtained by (3) is 17938. The results
show that the validity of the presented method and he
proposed method has advantages of meeting the minimum
element spacing constraint and forming a uniform
separations.
III. S IMULATION R ESULTS
Simulation results have been carried out to demonstrate
the feasibility of the proposed method. The results obtained
by the novel modified objective function are compared with
those obtained by the objective function proposed by. In the
simulation, number of elements is twenty-one, operating
frequency band is 94GHz, layout diameter is 300mm. The
element positions and separations for given set of element
positions obtained by Cornwell algorithm and the proposed
method are shown in Fig.2 and Fig.3. respectively. Element
(a)
(b)
Fig. 2. Element positions. (a) Element positions in Cornwell algorithm ; (b) Element positions in the proposed method.
(a)
(b)
Fig. 3. Separations for given set of element positions. (a) Separations in Cornwell algorithm; (b) Separations in the proposed method.
191