Double slot array antenna design method and double slot array antenna designed thereby
A method for designing a double slot array antenna is disclosed, aiming to achieve a beam pattern similar to a target azimuth pattern and low side lobe levels. The method involves seven steps: (a) Setting the number of radiation elements and the required radiated power ratio; (b) modeling a unit cell simulation model; (c) setting the main slot offset distance; (d) deriving azimuth beam patterns for various cases by changing the sub-slot offset and length; (e) selecting a similar azimuth beam pattern by comparing patterns to a target pattern; (f) calculating the radiated power ratio for the selected case; and (g) finally, comparing the calculated power ratio with the set ratio to determine the final design value of each element.
1 . A method for designing a double slot array antenna, comprising:
a) setting the number of radiation elements of a double slot structure arranged in a waveguide of an array antenna to be designed, and setting a radiated power ratio required for each of the radiation elements;
(b) modeling a simulation model for each of the radiation elements;
(c) setting an offset distance of a main slot of each of the radiation elements applied to the simulation model;
(d) deriving azimuth beam patterns for cases in which an offset distance and a length of a sub-slot of each of the radiation elements applied to the simulation model are changed;
(e) selecting a similar azimuth beam pattern similar to a target azimuth beam pattern among the derived azimuth beam patterns;
(f) calculating a radiated power ratio for the case corresponding to the similar azimuth beam pattern; and
(g) comparing the calculated radiated power ratio with the set radiated power ratio to determine a design value of each of the radiation elements.
2 . The method of claim 1 , wherein a length of the main slot applied to the simulation model is determined as half of the wavelength of an electromagnetic wave radiated into air.
3 . The method of claim 1 , wherein the main slot and the sub-slot of each of the radiation elements are disposed in a first region and a second region facing each other with a center line in an extension direction of the waveguide interposed, respectively, or are disposed in the second region and the first region.
4 . The method of claim 3 , wherein the simulation model for each of the radiation elements is modeled in response to an arrangement form between the main slot and the sub-slot of each of the radiation elements.
5 . The method of claim 1 , wherein in the step (b), the simulation model is modeled in a form in which the periphery is grounded.
6 . The method of claim 1 , wherein in the step (e), the similar azimuth beam pattern is selected by using a root mean square error between the target azimuth beam pattern and the derived azimuth beam patterns.
7 . The method of claim 6 , wherein the step (e) comprises:
calculating root mean square error values of the derived azimuth beam patterns with respect to the target azimuth beam pattern;
deriving a minimum value among the calculated root mean square error values; and
selecting the azimuth beam pattern corresponding to the minimum value as the similar azimuth beam pattern when the minimum value is equal to or less than a set value, and returning to the step (d) when the minimum value exceeds the set value.
8 . The method of claim 7 , wherein the set value is 0.5.
9 . The method of claim 1 , wherein in the step (g), when a difference between the calculated radiated power ratio and the set radiated power ratio is within an error range, an offset distance value of the main slot, an offset distance value of the sub-slot, and a length value of the sub-slot applied to the case corresponding to the similar azimuth beam pattern are determined as a design value of each of the radiation elements, and returning to the step (c) when the difference between the calculated radiated power ratio and the set radiated power ratio is out of the error range.
10 . The method of claim 9 , wherein the error range is 0.001 or less.
11 . A method for designing a double slot array antenna, comprising:
(J) deriving a design curve for antenna design;
(K) setting the number of radiation elements to be designed having a double slot structure of an array antenna to be designed, and setting a radiated power ratio required for each radiation element to be designed; and
(L) determining a design value of each radiation element to be designed based on the set radiated power ratio and the design curve for antenna design,
wherein the design curve for antenna design is derived based on data acquired through the design method according to claim 1 .
12 . The method of claim 11 , wherein in the step (L),
the radiated power ratio required for each radiation element to be designed is substituted into the design curve for antenna design, and the matched offset distance value of the main slot, the offset distance value of the sub slot, and the length value of the sub slot are determined as the design value of each radiation element to be designed.
13 . A double slot array antenna designed by the design method according to claim 1 .