Communications: radio wave antennas – Antennas – With radio cabinet
Reexamination Certificate
2000-07-21
2001-12-04
Le, Hoanganh (Department: 2821)
Communications: radio wave antennas
Antennas
With radio cabinet
C343S7000MS
Reexamination Certificate
active
06326927
ABSTRACT:
FIELD OF THE INVENTION
This invention relates generally to a compact antenna structure, and in particular to an antenna structure which is suitably utilized with a wireless communication device.
BACKGROUND OF IN THE INVENTION
Many wireless transceivers, and hand-held cell phones in particular, currently use external whip antennas that radiate nominally omnidirectionally. Little or no reduction is provided in transmitted RF energy that is directed toward the user's head. As a result, typical specific absorption rate (SAR) values of 2.7 mw/g at 0.5 watts input are realized. Additionally, the external assembly of a whip antenna can be relatively massive (weighing 8-9 grams) and may be subject to damage during use. The gain performance characteristic of the whip antenna is typically in the range −5 to +1.5 dBi. High-speed manufacturing and assembly techniques of wireless communication devices are typically not practicable with whip antennas, as such antennas typically require manual assembly and installation.
Also known are patch-type antennas. Known limitations of patch antennas include their relatively large size (approximately 4-10 times larger in volume than the current invention) required to provide a necessary operating bandwidth. Substantially large ground planes are also required with patch antennas to achieve the same front-to-back ratio as the current invention. Large ground planes are not practicable for use in today's hand-held wireless communication devices.
SUMMARY OF THE INVENTION
The present invention provides a compact antenna system having improved gain and front-to-back ratio. The antenna assembly according to the present invention may provide linear polarization and is suitable for use in wireless communications devices such as cellphones, PDA's, etc. The antenna assembly, when combined with a hand-held wireless transceiver, provides a far-field front-to-back ratio of 4 dB nominal, a specific absorption rate (SAR) on the order of 1.6 mw/g nominal on the rear side (toward the device user) with 0.5 watts power input to the antenna, and forward gain (away from the user's head) of +1.5 dB nominal. Relative size of the antenna is compatible with current wireless communication devices such that it may be easily integrated into or within the top rear portion of a wireless device.
The antenna may be characterized as a shorted, capacitively-tuned ⅛-wavelength broadband patch antenna. However, it provides substantial reduction in size over conventional ¼ or ½ wavelength patch antennas with similar operating bandwidths and front-to-back ratios. Additionally, signal polarization may be predetermined by choice of feedpoint, with linear or circular polarizations possible.
An object of the present invention is to provide an antenna that is capable of being surface-mounting to a transceiver dielectric substrate, such as its PWB (printed wiring board), in a high-volume production setting. Yet another object of the present invention provides an antenna that is capable of being placed away from and partially encompassing other components upon a transceiver PWB. The antenna defines an interior region between the radiator and the dielectric substrate within which other component of the wireless device may be disposed.
Another object of the present invention is to provide an antenna having a 3 dB beamwidth of between 110-160 degrees, as compared to a value of approximately 80 degrees of known dipole antenna devices. Additionally, an object of the present invention is to provide an antenna assembly having an operating bandwidth (2:1 VSWR) of 8% nominal over cellular telephone and PCS frequency ranges of 824-894 MHz and 1750-1990 MHz, respectively.
Another object of the invention is an antenna assembly that provides an improved specific absorption rate, and enhanced performance characteristics, such as gain, and front to back ratio.
Still another object of the invention is to provide an antenna assembly which may be incorporated within the wireless device housing.
These and other objects of the present invention will be apparent to those skilled in the relevant arts.
REFERENCES:
patent: 4443802 (1984-04-01), Mayes
patent: 4980694 (1990-12-01), Hines
patent: 5041838 (1991-08-01), Liimatainen et al.
patent: 5124733 (1992-06-01), Haneishi
patent: 5537123 (1996-07-01), Mandai et al.
patent: 5585810 (1996-12-01), Tsuru et al.
patent: 5757333 (1998-05-01), Kitchener
patent: 5764190 (1998-06-01), Murch et al.
patent: 5767810 (1998-06-01), Hagiwara et al.
patent: 5872544 (1999-02-01), Schay
patent: 5912647 (1999-06-01), Tsuru et al.
patent: 5917450 (1999-06-01), Tsunekawa
patent: 5940041 (1999-08-01), Koyama et al.
patent: 5969680 (1999-10-01), Tsuru et al.
patent: 6002367 (1999-12-01), Engblom et al.
patent: 6008764 (1999-12-01), Ollikainen et al.
Hill Robert
Johnson Greg
Keilen Don
Klas John F.
Larkin Hoffman Daly & Lindgren Ltd.
Le Hoang-anh
Nguyen Hoang
Range Star Wireless, Inc.
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