Planar inverted "F" antenna and method of tuning same

• US 20060038721A1
• Filed: 08/20/2004
• Published: 02/23/2006
• Est. Priority Date: 08/20/2004
• Status: Active Grant

• Current Assignee: Kyocera Corporation, Kyocera Wireless Corporation (Kyocera Corporation)
• Original Assignee: Kyocera Corporation
• Inventors: Ozkar, Mete, Poilasne, Gregory
• Granted Patent: US 7,345,634 B2
• Time in Patent Office: Days
• US Class Current: 343/700.MS
• CPC Class Codes: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 9/0421 with a shorting wall or a shorting pin at one end of the element H01Q9/0414 takes precedence
• CPC Class Codes: H01Q 9/0442 with particular tuning means

Abstract

A multiband planar inverted F antenna (PIFA) can provide improved performance and operating efficiency, and utilizes a capacitive element configured to provide high efficiency operation, and a tuning area that allows the antenna to be tuned independently of the capacitive element. As a result of this feature, the antenna can be tuned to the desired operating frequencies, while allowing the capacitive element to remain configured for optimal operating efficiency. The antenna can be configured in a loop for effective utilization of a given volume and can therefore be relatively small in size and high efficiency. A capacitive loading section can be included to allow improved antenna efficiency and radiation. Additionally, tuning section can be provided to allow the antenna to be tuned without adjusting the capacitive loading section. To obtain operation at an additional frequency band, a parasitic element or a slot configuration can be included.

Claims

1. A planar inverted F antenna, comprising:

a. a ground plane;

b. a radiating element positioned approximately parallel to the ground plane, the radiating element comprising;

first and second ends;

a first conductive section extending a first distance toward the ground plane and having first and second ends, the first end of the first conductive section electrically connected to the radiating element at a location proximal to the second end of radiating element;

a second conductive section being approximately parallel to the ground plane and connected to the second end of the first conductive element and extending from the distal end in a direction toward the first end of the radiating element; and

c. a ground post, electrically connecting the radiating element to the ground plane, the ground post disposed at a location proximal to the first end of the radiating element;

d. a feed electrically connected to the radiating element and disposed at a location proximal to the ground post; and

e. a tuning element electrically coupled to the radiating element and configured to allow tuning of the antenna in a manner having negligible effect on the antenna efficiency.

2. The antenna of claim 1, further comprising at least one parasitic element electrically connected to the radiating element, and configured to allow operation at an additional frequency band.

3. The antenna of claim 1, wherein said tuning element comprises at least one of a variable length radiating section and a circuit element.

4. The antenna of claim 1, wherein the ground post is at least one of a pin, post or wall.

5. The antenna of claim 1, wherein the antenna is mounted within a housing of a wireless device.

6. The antenna of claim 1, wherein the radiating element is configured in the form of a loop.

7. The antenna of claim 1, wherein the radiating element comprises two inverted L-shaped sections disposed adjacent to a partially opened loop section, such that one end of each the inverted L-shaped section is electrically connected to a respective end of the partially opened loop section.

8. An antenna, comprising:

a. a radiating element positioned approximately parallel to a ground plane;

b. a ground post, electrically connecting the radiating element to the ground plane;

c. a feed electrically connected to the radiating element and disposed at a location proximal to the ground post;

d. a capacitive loading section configured to provide capacitive coupling of the antenna; and

e. a tuning element configured to provide tuning of the antenna independently of the capacitive loading section.

9. The antenna of claim 8, wherein the capacitive loading section comprises:

a. a first conductive section extending a first distance toward the ground plane and having first and second ends, the first end of the first conductive section electrically connected to the radiating element; and

b. a second conductive section being approximately parallel to the conductor plate and connected to the second end of the first conductive element and extending from the second end of the first conductive element.

10. The antenna of claim 8, wherein said capacitive loading section comprises:

a. a first conductive section electrically connected to the radiating element and extending a first distance toward the ground plane; and

b. a second conductive section electrically connected to the ground plane and extending from the ground plane in a direction toward a plane of the radiating element, the second conductive section being approximately parallel to the first conductive section.

11. The antenna of claim 8 wherein the radiating element comprises two inverted L-shaped sections disposed adjacent to a partially opened loop section, such that one end of each of the inverted L-shaped sections is electrically connected to a respective end of the partially opened loop section.

12. The antenna of claim 8, further comprising at least one of a parasitic element and a slot to provide operation at one or more additional frequency bands.

13. The antenna of claim 8, wherein the ground post is at least one of a pin, post or wall.

14. The antenna of claim 8, wherein the antenna is mounted within a housing of a wireless device.

15. A wireless communication device, comprising:

a. a printed circuit board including one or more operational components of the wireless communication device, the printed circuit board including a radio transmitter and receiver and a ground plane;

b. an antenna, comprising;

i. a radiating element positioned approximately parallel to the ground plane;

ii. a ground post, electrically connecting the radiating element to the ground plane;

iii. a feed electrically connecting the radiating element to the at least one of a radio transmitter and receiver;

iv. a capacitive loading section configured to provide capacitive coupling of the antenna; and

v. a tuning element configured to provide tuning of the antenna independently of the capacitive loading section.

16. The wireless communication device of claim 15, wherein the capacitive loading section comprises:

a. a first conductive section extending a first distance toward the ground plane and having first and second ends, said first end of the first conductive section electrically connected to the radiating element; and

b. a second conductive section being approximately parallel to the conductor plate and connected to the second end of the first conductive element and extending from the second end of the first conductive element.

17. The wireless communication device of claim 15, wherein the capacitive loading section comprises:

a. a first conductive section electrically connected to the radiating element and extending a first distance toward the ground plane; and

b. a second conductive section electrically connected to the ground plane and extending from the ground plane in a direction toward a plane of the radiating element, the second conductive section being approximately parallel to the first conductive section.

18. The wireless communication device of claim 15, wherein the radiating element comprises two inverted L-shaped sections disposed adjacent to a partially opened loop section, such that one end of each of the inverted L-shaped sections is electrically connected to a respective end of the partially opened loop section.

19. The wireless communication device of claim 15, further comprising at least one of a parasitic element and a slot to provide operation at one or more additional frequency bands.

20. The wireless communication device of claim 15, wherein the wireless communication device is one of a cell phone, radio telephone, radio handset, pager, WiLAN component, or GPS receiver.

21. A method for tuning an antenna comprising a radiating element, a capacitive loading section and a tuning element, the method comprising:

a. determining one or more operational parameters of the antenna, wherein said operational parameters include one of operating frequency, bandwidth, and impedance;

b. configuring the capacitive loading section of the antenna such that the antenna radiates effectively for the one or more determined operational parameters; and

c. using a tuning element to adjust the frequency response of the antenna without substantially adjusting the configuration of the capacitive loading as performed in step b.

22. The method of claim 21, further comprising:

locating a feed point at a location proximal to a ground post so as to match the antenna to circuitry of a wireless device.

23. The method of claim 21, further comprising:

adding at least one of a parasitic element and a slot to provide operation at one or more additional frequency bands.

24. The method of claim 21, further comprising:

mounting said antenna in proximity to a ground plane of a printed circuit board, and electrically connecting the radiator of the antenna to said ground plane via a ground post.