Electromagnetic wave reflecting structure and manufacturing method thereof
A method of manufacturing an electromagnetic wave reflecting structure includes the steps of presetting an operating frequency, a reflected wave pointing angle, an incident wave pointing angle, and an incident distance of an electromagnetic wave; obtaining an electromagnetic wave reflecting structure phase distribution of an electromagnetic wave reflecting structure according to the operating frequency, the reflected wave pointing angle, the incident wave pointing angle, and the incident distance; and arranging a plurality of reflecting elements on a substrate according to the electromagnetic wave reflecting structure phase distribution and a reflecting element phase curve of any one of the reflecting elements at the operating frequency.
1. An electromagnetic wave reflecting structure, adapted for guiding an electromagnetic wave emitted from an electromagnetic wave source to be reflected at a reflected wave pointing angle, the electromagnetic wave being incident at an incident wave pointing angle and having an operating frequency, the electromagnetic wave reflecting structure comprising:
a substrate having a surface on which a reference point is defined; and
a plurality of reflecting elements disposed on the surface;
wherein a reflection phase shift of an i-th reflecting element of the plurality of reflecting elements is related to a coordinate location of the i-th reflecting element with respect to the reference point, a wave number at the operation frequency, the reflected wave pointing angle, and an incident distance of the electromagnetic wave source to the i-th reflecting element;
wherein a size of the i-th reflecting element of the plurality of reflecting elements is related to the reflection phase shift of the i-th reflecting element on the substrate and a reflection phase of any one of the plurality of reflecting elements at the operating frequency, and
wherein each reflecting element includes two first metal sheets and two second metal sheets, wherein each first metal sheet has a horseshoe shape, wherein the first metal sheets are arranged facing each other to form a rectangle, wherein a first spacing P is defined between the first metal sheets, wherein each second metal sheet is configured in a substantially rectangular shape, the second metal sheets being arranged side by side between the first metal sheets, wherein a second spacing S is defined between proximal side edges of the second metal sheets, wherein the spacing S is unchanged along an entire length L of the second metal sheets.
2. The electromagnetic wave reflecting structure as claimed in claim 1 , wherein the reflection phase shift of the i-th reflecting element on the substrate and the incident distance of the electromagnetic wave source to the i-th reflecting element are obtained by the following formulas:
Φ R ( x i ,y i )= k[d i −( x i cos Φ B +y i sin Φ B )sin θ B ]±2 Nπ (1)
d i =[( x F −x i ) 2 +( y F −y i ) 2 +z F 2 ] 0.5 (2)
wherein (x i , y i ) is the coordinate location of the i-th reflecting element relative to the reference point, Φ R (x i , y i ) is the reflection phase shift of the i-th reflecting element, k is a wave number at the operating frequency, (θ B , Φ B ) is the reflected wave pointing angle, d i is the incident distance of the electromagnetic wave source to the i-th reflecting element, (x F , y F , z F ) is a spatial coordinate location of the electromagnetic wave source relative to the reference point, and N is a nature number.
3. An electromagnetic wave reflecting structure adapted for guiding an electromagnetic wave emitted from an electromagnetic wave source to be reflected at a reflected wave pointing angle, the electromagnetic wave being incident at an incident wave pointing angle and having an operating frequency, the electromagnetic wave reflecting structure comprising:
a substrate having a surface on which a reference point is defined, and
a plurality of reflecting elements disposed on the surface,
wherein a reflection phase shift of an i-th reflecting element of the plurality of reflecting elements is related to a coordinate location of the i-th reflecting element with respect to the reference point, a wave number at the operation frequency, the reflected wave pointing angle, and an incident distance of the electromagnetic wave source to the i-th reflecting element,
wherein a size of the i-th reflecting element of the plurality of reflecting elements is related to the reflection phase shift of the i-th reflecting element on the substrate and a reflection phase of any one of the plurality of reflecting elements at the operating frequency,
wherein each reflecting element includes two first metal sheets and two second metal sheets, wherein each first metal sheet has a horseshoe shape, wherein the first metal sheets are arranged facing each other to form a rectangle, wherein a first spacing P is defined between the first metal sheets, wherein each second metal sheet is substantially rectangular, the second metal sheets being arranged side by side between the first metal sheets, wherein a second spacing S is defined between the second metal sheets, and
wherein each first metal sheet includes an extension section and two turning sections, the turning sections are connected to two ends of the extension section respectively and extend in a direction perpendicular to the extension section, a length of the extension section of any one of the first metal sheets is substantially equal to the length L of each second metal sheet plus six times a width of any one of the turning sections, a length of each turning section is substantially equal to one half of the length of the extension section minus the first spacing P, and a width of each second metal sheet is substantially equal to one half of the length L of each second metal sheet minus the second spacing S.