The present invention relates generally to planar antennas and, more particularly, to planar inverted “F” antennas that can be flexed without degrading antenna performance.
The need for planar antennas has grown tremendously due to the proliferation of all kinds of hand-held and portable wireless devices where the area reserved for antenna location continues to shrink. This need has been met by planar antennas, especially those known as planar inverted “F” antennas, or PIFAs. As shown in
However, there remains a need to provide for a flexible PIFA that can be used on various kinds of articles (e.g., curved enclosures, wearables, etc.) that do not include flat surfaces for mounting without degrading the PIFA antenna performance. In addition, this need also includes providing a PIFA that is less sensitive to the presence of a living body in the near field, as well as being less sensitive to the presence of metal, than are traditional antennas.
All references cited herein are incorporated herein by reference in their entireties.
A flexible planar inverted “F” antenna (PIFA) is disclosed. The flexible PIFA comprises: a flexible printed circuit board (PCB, e.g., a flexible dielectric material, a polyimide PCB, etc.) having a metal layer (e.g., copper, etc.) on a first side that is covered by a cover layer (e.g., also a flexible dielectric material), wherein the flexible PCB comprises a second side opposite the first side; a flexible dielectric element (e.g., a flexible dielectric material, a foam, ethyl vinyl acetate foam, etc.) around which the second side is folded to form a main element and a ground plate that are substantially parallel to each other; a cable (e.g., a coaxial cable) having a first end electrically connected to the metal layer and having a second end adapted to electrically connect to a wireless device; and wherein the flexible PIFA comprises an antenna performance when electrically connected to the wireless device and wherein the antenna performance is maintained when the flexible PIFA is bent into a concave shape or into a convex shape.
A method for providing a flexible planar inverted “F” antenna (PIFA) that can operate when secured to a curved surface is disclosed. The method comprises: forming a metal layer (e.g., copper, etc.) on a first side of a flexible printed circuit board (PCB, e.g., a flexible dielectric material, a polyimide PCB, etc.) having a cover layer (e.g., also a flexible dielectric material) positioned over the metal layer, and wherein the flexible PCB has a second side opposite the first side; folding the second side around a flexible dielectric element (e.g., a flexible dielectric material, a foam, ethyl vinyl acetate foam, etc.) to form a main element and a ground plate that are substantially parallel to each other; electrically connecting a first end of a conductor (e.g., a cable) to the metal layer and electrically connecting a second end of the conductor to a wireless device to form an antenna comprising an antenna performance; and securing the ground plate to a concave surface or a convex surface and wherein the antenna performance is maintained while the flexible PIFA is in use.
A method for providing a flexible planar inverted “F” antenna (PIFA) that can operate when secured to a metal surface is disclosed. The method comprises: forming a metal layer (e.g., copper, etc.) on a first side of a flexible printed circuit board (PCB, e.g., a flexible dielectric material, a polyimide PCB, etc.) having a cover layer (e.g., also a flexible dielectric material) positioned over the metal layer and wherein the flexible PCB has a second side opposite the first side; folding the second side around a flexible dielectric element (e.g., a flexible dielectric material, a foam, ethyl vinyl acetate foam, etc.) to form a main element and a ground plate that are substantially parallel to each other; electrically connecting a first end of a conductor (e.g., a cable) to the metal layer and electrically connecting a second end of the conductor to a wireless device to form an antenna comprising an antenna performance; and securing the ground plate to the metal surface and wherein the antenna performance is maintained while the flexible PIFA is in use.
Many aspects of the present disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
Referring now to the figures, wherein like reference numerals represent like parts throughout the several views, exemplary embodiments of the present disclosure will be described in detail. Throughout this description, various components may be identified having specific values, these values are provided as exemplary embodiments and should not be limiting of various concepts of the present invention as many comparable sizes and/or values may be implemented.
The flexible PIFA 20 of the present invention is designed to resist de-tuning when physically flexed, is less sensitive to the presence of a living body in the near field and is less sensitive to the presence of metal than are traditional antennas. One version of the flexible PIFA 20 is designed for operation in the 2.400-2.483 GHz frequency band while another version is designed for dual use in the 2.400-2.483 GHz frequency band as well as in the 5.15-5.85 GHz frequency band.
As shown most clearly in
As shown most clearly in
To form the flexible PIFA 20 into its operative condition, the dielectric element 25 is applied to the reverse side 35 and the polyimide PCB 21 is folded around the dielectric element 25 into the structure shown in
The dual band flexible PIFA 20 is similar in formation as shown in
The flexible PIFA 20 is now ready for application to any desired surface. To accomplish this, the release sheet 36 is removed from the PCB 21 and the flexible PIFA 20 is secured to the desired surface. For example, the flexible PIFA 20 can be mounted on curved surfaces as is shown in
The following tables provide an overview, performance and physical characteristics, of the single band flexible PIFA 20 (2.400-2.483 GHz frequency band) as well as the dual band flexible PIFA 20 (2.400-2.483 GHz and 5.15-5.85 GHz frequency bands).
All such modifications and variations are intended to be included herein within the scope of this disclosure.
While the invention has been described in detail and with reference to specific examples thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.
Number | Name | Date | Kind |
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6480156 | Tsai | Nov 2002 | B2 |
7339528 | Wang | Mar 2008 | B2 |
7605765 | Ku | Oct 2009 | B2 |
7911387 | Hill | Mar 2011 | B2 |
8259017 | Schlub | Sep 2012 | B2 |
9257750 | Vazquez | Feb 2016 | B2 |
Number | Date | Country | |
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20150357717 A1 | Dec 2015 | US |