Wide frequency band planar antenna
A wide frequency band planar antenna comprises an elongated portion, substantially parallel to a circumferential edge of a ground pattern and comprising one end connected to a feeding transmission line, wherein there is a gap between the elongated portion and the circumferential edge of the ground pattern; a body stub and an impedance-matching-adjusting pattern for adjusting an impedance matching between the wide frequency band planar antenna and the feeding transmission line; wherein the gap value is less than 2 mm so as to enable the wide frequency band antenna to operate at a wide range of frequencies ranging from 2.3 GHz to near 6 GHz, thereby allowing the wide frequency band antenna to be applied in both WiFi LAN and WiMAX MAN.
1. A wide frequency band planar antenna formed on one-side surface of a circuit board, comprising:
an elongated portion, substantially parallel to a circumferential edge of a ground pattern formed on another-side surface of the circuit board, and comprising one end connected to a feeding transmission line, wherein there is a gap between the elongated portion and the circumferential edge of the ground pattern; and
a body stub, comprising an open end and another end connected to another end of the elongated portion to form an inverted-L-shaped pattern; wherein the gap value is less than 2 mm so as to enable the wide frequency band antenna to operate at a wide range of frequencies ranging from 2.3 GHz to near 6 GHz.
2. The wide frequency band planar antenna according to claim 1 , wherein the body stub is replaced by a patch pattern that is of rectangular shape with the near-feeding-transmission-line long side tapered outward, and the patch pattern at its shortest side is connected to the elongated portion.
3. The wide frequency band planar antenna according to claim 2 , wherein the impedance-matching-adjusting pattern is a short stub.
4. The wide frequency band planar antenna according to claim 2 , wherein the length of the elongated portion ranges from 7.5 mm-9.5 mm.
5. The wide frequency band planar antenna according to claim 2 , wherein the length of the body stub ranges from 11.5 mm-14.5 mm.
6. The wide frequency band planar antenna according to claim 1 , wherein the total path length of the wide frequency band planar antenna is equal to λ/4, wherein λ ranges from the lowest frequency to the highest frequency of the wide range of frequencies.
7. The wide frequency band planar antenna according to claim 1 , wherein the length of the elongated portion ranges from 7.5 mm-9.5 mm.
8. The wide frequency band planar antenna according to claim 1 , wherein the length of the body stub ranges from 11.5 mm-14.5 mm.
9. A wide frequency band planar antenna formed on one-side surface of a circuit board, comprising:
an elongated portion, substantially parallel to a circumferential edge of a ground pattern formed on the another-side surface of the circuit board, and comprising one end connected to a feeding transmission line, wherein there is a gap between the elongated portion and the circumferential edge of the ground pattern;
a body stub, comprising an open end and another end connected to another end of the elongated portion; and
an impedance-matching-adjusting pattern for adjusting an impedance matching between the wide frequency band planar antenna and the feeding transmission line, comprising one end short-circuited to the ground pattern through a via and another end connected to a joint between the elongated portion and the feeding transmission line; wherein the gap value is less than 2 mm so as to enable the wide frequency band antenna to operate at a wide range of frequencies ranging from 2.3 GHz to near 6 GHz.
10. The wide frequency band planar antenna according to claim 9 , wherein the body stub is replaced by a patch pattern that is of rectangular shape with the near-feeding-transmission-line long side tapered outward, and the patch pattern at its shortest side is connected to the elongated portion.
11. The wide frequency band planar antenna according to claim 10 , wherein the width of the impedance-matching-adjusting pattern is equal or is not equal to that of the elongated portion depending on a need for adjusting the impedance matching between the wide frequency band planar antenna and the feeding transmission line.
12. The wide frequency band planar antenna according to claim 11 , wherein the impedance-matching-adjusted pattern is a short stub.
13. The wide frequency band planar antenna according to claim 10 , wherein the length of the elongated portion ranges from 7.5 mm-9.5 mm.
14. The wide frequency band planar antenna according to claim 10 , wherein the length of the body stub ranges from 11.5 mm-14.5 mm.
15. The wide frequency band planar antenna according to claim 9 , wherein the width of the impedance-matching-adjusting pattern is equal or is not equal to that of the elongated portion depending on a need for adjusting the impedance matching between the wide frequency band planar antenna and the feeding transmission line.
16. The wide frequency band planar antenna according to claim 15 , wherein the impedance-matching-adjusted pattern is a short stub.
17. The wide frequency band planar antenna according to claim 9 , wherein the total path length of the wide frequency band planar antenna is equal to λ/4, wherein λ ranges from the lowest frequency to the highest frequency of the wide range of frequencies.
18. The wide frequency band planar antenna according to claim 9 , wherein the length of the elongated portion ranges from 7.5 mm-9.5 mm.
19. The wide frequency band planar antenna according to claim 9 , wherein the length of the body stub ranges from 11.5 mm-14.5 mm.