The present invention relates to antennas and, more particularly, dual frequency printed circuit board antennas.
Printed circuit board antennas are generally known in the art.
Thus, it would be desirous to provide an improved printed circuit board antenna having dual frequency operation and improved power feed.
To attain the advantages and in accordance with the present invention, a multiband antenna is provided. The multiband antenna comprises a ground plane with a first slot radiator of a first length and a second slot radiator of a second length, the first and second slot radiators have first and second feed ends, and first and second terminating ends, respectively. A single power feed extends from a source end attached to a power source to a radiator end. The radiator end has a first branch connected the radiator and a second branch connected to the second radiator. The two radiators may be of different lengths to facilitate multi-frequencies of operation.
The foregoing and other features, utilities and advantages of the invention will be apparent from the following more particular description of a preferred embodiment of the invention as illustrated in the accompanying drawings.
The present invention will now be explained with reference to
First radiating element 206 and second radiating element 208 may be straight radiating elements or have zigzag, meanderline, curved, or the like geometries.
Second radiating element 208 has a L shaped portion 210 at terminating end 208t. L shaped portion 210 could have other configurations, such as a C shape, a curve, a straight or I shape, a step shape or the like. Radiating portion 206 could have an alternative configuration at terminating end 206t if desired.
A feed connection 212 is coupled to each first radiating element 206 and second radiating element 208 proximate or at feed end 206f and 208f. Feed connection 212 comprises a microstrip feed line 214 and a tee connection 216. Tee connection 216 has a first branch 218 terminating in a short 218s that shorts the tee connection to ground plane 204 and a second branch 220 terminating in a short 220s that shorts the tee connection to ground plane 204. Short 218s and short 220s reside proximate by a short distance d away from first radiating element 206 and second radiating element 208. Tee connection 216 could take other shapes, such as, a Y shape or the like.
A power feed 220 connects to the microstrip feed line 214. If power feed 220 was a coaxial cable power feed, a conductor 222 of coaxial cable would attach to microstrip feed line 214 and a jacket 224 or ground of coaxial cable would attach to ground plane 204. Placement of tee connection 216 allows for impedance matching. Further, while explained using a coaxial cable as the power feed 220, any conventional power feed is possible.
In operation, first radiating element 206 (the shorter element) would operate at a higher frequency and second radiating element 208 (the longer element) would operate at a lower frequency. The elements could be tuned by varying the configuration, dimensions, and the like of each element.
While antenna 200 is a satisfactory antenna and an improvement over prior art designs, the size of antenna 200 could be reduced. In particular,
A feed connection 410 is coupled to each of first radiating element 406 and second radiating element 408 proximate or at feed ends 406f and 408f, respectively. Feed connection 410 comprises a microstrip feed line 412 and a tee connection 414 originating from a feed edge 416 of ground plane 404. Feed line 412 and tee connection 414 are similar to the devices described in connection with
Referring now to
While the invention has been particularly shown and described with reference to an embodiment thereof, it will be understood by those skilled in the art that various other changes in the form and details may be made without departing from the spirit and scope of the invention.
This application claims priority to U.S. Provisional Applications 60/552,933, filed Mar. 12, 2004, and 60/566,911, filed Apr. 30, 2004, titled the same, and incorporated herein as if set out in full.
Number | Date | Country | |
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60552933 | Mar 2004 | US | |
60566911 | Apr 2004 | US |