Antenna system

1. An antenna system, comprising:

a first antenna element;

a second antenna element;

a dielectric substrate, wherein the first antenna element and the second antenna element are disposed on the dielectric substrate;

a first reflective plate, disposed adjacent to the dielectric substrate; and

a second reflective plate, coupled to the first reflective plate, wherein a first angle is formed between the first reflective plate and the second reflective plate;

wherein the antenna system provides an HPBW (Half-Power Beamwidth) from 90 to 180 degrees;

wherein the antenna system covers an operational frequency band;

wherein a length of the first reflective plate is calculated using the following equation:

L

⁢

1

=

2

4

·

λ

·

(

K

⁢

2

)

where “L 1 ” represents the length of the first reflective plate, “λ” represents a wavelength of a central frequency of the operational frequency band, and “K 2 ” represents a second adjustment constant from 0.7 to 2.

2. The antenna system as claimed in claim 1 , wherein the operational frequency band is from 2300 MHz to 2700 MHz.

3. The antenna system as claimed in claim 2 , wherein a length of the second reflective plate is calculated using the following equation:

L

⁢

2

=

2

4

·

λ

·

(

K

⁢

2

)

where “L 2 ” represents the length of the second reflective plate, “λ” represents a wavelength of a central frequency of the operational frequency band, and “K 2 ” represents a second adjustment constant from 0.7 to 2.

4. The antenna system as claimed in claim 2 , further comprising:

a third reflective plate, coupled to the first reflective plate and the second reflective plate, wherein the third reflective plate is disposed between the first antenna element and the second antenna element.

5. The antenna system as claimed in claim 4 , wherein a combination of the first reflective plate, the second reflective plate, and the third reflective plate substantially has a Y-shape.

6. The antenna system as claimed in claim 4 , wherein a length of the third reflective plate is calculated using the following equation:

L

⁢

3

=

2

4

·

λ

·

(

K

⁢

3

)

where “L 3 ” represents the length of the third reflective plate, “λ” represents a wavelength of a central frequency of the operational frequency band, and “K 3 ” represents a third adjustment constant from 0 to 1.5.

7. The antenna system as claimed in claim 2 , wherein the dielectric substrate has a first surface and a second surface opposite to each other.

8. The antenna system as claimed in claim 7 , wherein the first antenna element comprises:

a first radiation element, disposed on the first surface of the dielectric substrate; and

a second radiation element, disposed on the second surface of the dielectric substrate, wherein the first radiation element and the second radiation element substantially extend in opposite directions.

9. The antenna system as claimed in claim 8 , wherein a length of each of the first radiation element and the second radiation element is substantially equal to 0.25 wavelength of a central frequency of the operational frequency band.

10. The antenna system as claimed in claim 8 , wherein the second antenna element comprises:

a third radiation element, disposed on the first surface of the dielectric substrate; and

a fourth radiation element, disposed on the second surface of the dielectric substrate, wherein the third radiation element and the fourth radiation element substantially extend in opposite directions.

11. The antenna system as claimed in claim 10 , wherein a length of each of the third radiation element and the fourth radiation element is substantially equal to 0.25 wavelength of a central frequency of the operational frequency band.

12. The antenna system as claimed in claim 10 , wherein a first distance is defined between a central point of the second radiation element and the first reflective plate, and a second distance is defined between a central point of the fourth radiation element and the second reflective plate.

13. The antenna system as claimed in claim 12 , wherein the first distance is calculated using the following equation:

D

⁢

1

=

1

4

·

λ

·

(

K

⁢

4

)

where “D 1 ” represents the first distance, “λ” represents a wavelength of a central frequency of the operational frequency band, and “K 4 ” represents a fourth adjustment constant from 0.7 to 2.

14. The antenna system as claimed in claim 12 , wherein the second distance is calculated using the following equation:

D

⁢

2

=

1

4

·

λ

·

(

K

⁢

4

)

where “D 2 ” represents the second distance, “λ” represents a wavelength of a central frequency of the operational frequency band, and “K 4 ” represents a fourth adjustment constant from 0.7 to 2.

15. The antenna system as claimed in claim 1 , wherein each of the first antenna element and the second antenna element is a dipole antenna.

16. The antenna system as claimed in claim 1 , wherein the first angle is calculated using the following equation:

θ

⁢

1

=

180

⁢

°

-

(

θ

⁢

B

)

2

·

(

K

⁢

1

)

where “θ 1 ” represents the first angle, “θB” represents the HPBW, and “K 1 ” represents a first adjustment constant from 0.8 to 1.2.

17. The antenna system as claimed in claim 1 , wherein a second angle is formed between the first reflective plate and the dielectric substrate, a third angle is formed between the second reflective plate and the dielectric substrate, and the second angle and the third angle are substantially equal to each other.

18. The antenna system as claimed in claim 1 , further comprising:

a first transmission line, wherein a signal source is coupled through the first transmission line to the first antenna element; and

a second transmission line, wherein the signal source is further coupled through the second transmission line to the second antenna element.