Communications: radio wave antennas – Antennas – With radio cabinet
Reexamination Certificate
1999-12-02
2001-07-03
Le, Hoanganh (Department: 2821)
Communications: radio wave antennas
Antennas
With radio cabinet
C343S895000, C343S725000
Reexamination Certificate
active
06255996
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention pertains to wireless communication devices. More particularly, the invention relates to antenna systems used with such devices.
2. Description of the Related Art
Wireless communication devices are becoming increasingly prevalent, with cellular telephones being a particularly notable example. With these devices, radio-frequency (RF) signals are transmitted and received to create a communication link to the device.
Most wireless communication devices contain one or more antennas protruding from a surface of the device to facilitate transmission and reception of the RF signals. Therefore, the upper surface of the device is usually the most efficient location for an antenna because this location provides the antenna the clearest path to and from the device. This antenna location also allows for some form of extendable whip antenna to be extended without interfering with the user's operation of the device. Numerous antenna systems exist which contain one or more antennas located on the upper surface of a wireless communication device.
Referring now to
FIGS. 1A-1C
, one type of prior art wireless communication device
90
is illustrated.
FIG. 1A
illustrates a frontal elevation view of a wireless communication device
90
.
FIG. 1B
illustrates a side elevation view of the wireless communication device.
FIG. 1C
illustrates a top elevation view of the wireless communication device
90
. The device
90
may be, for example, a cellular telephone, or other wireless communication product. The device
90
shown in
FIGS. 1A-1C
contains both a monopole whip antenna
92
and a helical antenna
94
. The monopole whip antenna
92
extends through the center of the helical antenna
94
. When the monopole whip antenna
92
is extended, the helical antenna
94
is disengaged from the transceiver and the monopole whip antenna
92
is used to transmit and receive RF signals. When the monopole whip antenna
90
is less than fully extended, the helical antenna
94
is engaged with the transceiver and the helical antenna
94
is used to transmit and receive RF signals.
Typically, the wireless communication device
90
exchanges wireless link signals with a base station. As the signals travel between the wireless communication device
90
and the base station, the signal energy of the RF signal dissipates exponentially as a function of the distance that the signal travels. In addition, the RF signals also dissipate when they pass through or reflect off of objects such as buildings, people or cars. In addition, when the helical antenna
94
is used, considerable signal loss can occur if the user's head disrupts the wireless link path between the wireless communication device
90
and the base station. When the monopole whip antenna
92
is extended, it extends up past the head of the user. However, the helical antenna
94
, by nature of its small design, is more susceptible to path loss due to the user's head. For this reason, generally, the wireless communication device
90
performs better when the monopole whip antenna
92
is engaged.
Many standard wireless devices are sold today with the antenna configuration shown in FIG.
1
. This configuration allows the user to operate the device with the monopole whip antenna
92
less than fully extended for the convenience of the user. For example, extending the antenna can require additional motion from the user who may wish to answer a ringing phone quickly. In addition, in certain operating conditions, such as in a crowded area or confined automobile, it is impractical to fully extend the monopole whip antenna
92
. In these instances, it is common for the user to operate the wireless communication device
90
with the monopole whip antenna
92
less than fully extended.
The increase in path loss means that either the performance of the system is adversely impacted or that the transmitted signal power must be increased. Adverse changes in performance are often intolerable to system operation and can result in system failure. Increasing the transmitted signal power can result in reduced battery life, large heat dissipation problems and difficulty in meeting government signal level limit requirements. For this reasons, some systems are designed such that the user is unable to use of the helical antenna
94
to establish communication in some limited regions of the system.
It will be appreciated that there is a need in the technology for a means and method that minimizes the loss resulting from signals being forced to pass through the user's head in these circumstances.
SUMMARY OF THE INVENTION
The invention is a novel and improved antenna system for wireless communication devices. According to the invention, a helical antenna or other low profile antenna is located at the end of a boom. The boom protrudes laterally away from the device increasing the distance between the user's head and the helical antenna. In one embodiment, the system also contains a retractable monopole whip antenna located on the top of the wireless communication device. In another embodiment, the boom can rotate 90 degrees to be located over the upper surface of the wireless communication device for easy storage when the device is not in use. In yet another embodiment, the boom telescopically extends away from the wireless communication device.
This system improves the transmission efficiency of the wireless communication device when the whip antenna is retracted and the helical antenna is used to transmit RF signals or when the device only contains a helical antenna. Therefore, by moving the helical antenna a short distance away from the user's head, the system improves signal quality by minimizing loss near the antenna.
REFERENCES:
patent: D. 417221 (1999-11-01), Johnson et al.
patent: 5541609 (1996-07-01), Stuzman et al.
patent: 5905966 (1999-05-01), Yoshihara et al.
patent: 6028556 (2000-02-01), Shiraki
patent: 6107966 (2000-08-01), Fahlberg
Brown Charles D.
Hom Raymond B.
Le Hoang-anh
Qualcomm Incorporated
Wadsworth Philip
LandOfFree
Efficient antenna system for a personal communication device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Efficient antenna system for a personal communication device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Efficient antenna system for a personal communication device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2519956