Patent Application
20130044030
Current and next-generation wireless handsets need wide-band, multi-band antennas. This need is becoming particularly acute with the spreading adoption of fourth-generation long-term evolution (4G LTE) technology. Antenna bandwidth requirements have increased with this technology because the 700 megahertz (MHz) frequency bands are specified for 4G LTE. In addition, any such antenna must fit within the enclosure of a mobile telephone.
The drawings illustrate by example aspects and implementations of the invention.
In the drawings and in this description, examples and details are used to illustrate principles of the invention. However, other configurations may suggest themselves, and the invention may be practiced without limitation to the details and arrangements as described. Some known methods and structures have not been described in detail in order to avoid obscuring the invention. The invention is to be limited only by the claims, not by the drawings or this description.
Any dimensions are approximate. Terms of orientation such as “top” and “bottom” are used only for convenience to indicate spatial relationships of components with respect to each other; unless otherwise indicated, orientation is not critical to proper functioning of the invention. In the drawings and in this description, the same reference numerals will be used throughout to refer to the same or like parts.
There is a need for an antenna that can fit within the confines of a portable appliance such as a mobile phone and that is operable both in existing frequency bands and in the new 4G LTE 700 MHz frequency bands. Referring to
The conductor may connect at a connection point 117 to an electronic component (not shown) carried by the printed circuit board, or the conductor may extend to a location remote from the circuit board. The conductor may comprise a radio-frequency waveguide.
Referring to
The main body 301 may extend substantially from a first edge 307 of the printed circuit board to an opposing second edge 309.
The main body may have a width 311, and the first and second transverse elements may each have substantially the same width as the main body. Or as shown in
Dimensions may be determined by the available space in a mobile phone enclosure, or by desired frequency bands. In a prototype, the printed circuit board had overall dimensions of about 60 millimeters wide by 110 millimeters long. In this version the main body of the low-band ground-coupled arm was as long as the width of the circuit hoard, that is 60 millimeters, the first transverse element was about 11 millimeters in length and the second transverse element was about 6 millimeters in length.
The high-band ground-coupled arm 109 may comprise an elongated main body 311 and an elongated transverse element 313 at an extremity of the main body, generally at right angles to the main body, terminating at the ground plane. The transverse element 313 is electrically connected to the ground plane.
The feed arm 113 may comprise an elongated main body 315 and an elongated transverse element 317 at an extremity of the main body, generally at right angles to the main body. The transverse element 317 terminates at the conductor 115 and is electrically connected to the conductor, establishing the electrical connection between the conductor and the feed arm.
The feed arm 113 may cross over the high-band ground-coupled arm 109. These two arms are spaced apart from each other by the printed circuit board, the feed arm being disposed on the first surface 103 and the high-band ground-coupled arm 109 being disposed on the second surface 111 of the printed circuit board. The main body 315 of the feed arm crosses over the transverse element 313 of the high-band ground-coupled arm in the configuration shown in the drawings.
As shown in
Similarly, the feed arm 113 is formed in a portion 505 of the first sheet of metal foil that is electrically isolated from any other portion of the first sheet of metal foil, for example by etching the foil. Both arms 101 and 113 may be formed in a single etching operation as desired.
The high-band ground-coupled arm 109 may be formed in a portion 603 of the second sheet of metal foil, for example by etching the foil to define the arm 109.
Referring again to
Turning again to
Similarly, a space 323 between the low-band arm 101 from the high-band arm 109 may be substantially identical in size to the width 311 of the low-band arm or it may differ. Also a space 325 that separates the high-band arm 109 from the feed arm 113 may be the same size as, or different than, the width 319 of the high-band arm or width 321 of the feed arm.
Turning again to
Finally,
An antenna implementing principles of the invention as described above can be fabricated on a printed circuit board (FR4) and can accommodate the 700 MHz LTE bands while still covering the 0.85 GHz, 0.90 GHz, and 1.9 GHz frequency bands. The ground-coupled arms, used as part of the radiation elements, achieves multi-mode antenna resonances resulting in wide low-band bandwidth. These multi-mode resonances are achieved by capacitively coupling energy from the feed arm (driven antenna element) to the ground-coupled arms in order to re-radiate the coupled energy at the desired frequencies.
