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Mobile Phone Patent Abstract
A hand-held satellite mobile phone terminal contains an antenna
deployment element with a small antenna attached to the tip area
of the antenna deployment element The antenna deployment element
is usually folded and stored on the rear side surface of the body
of the hand-held satellite mobile phone terminal, and is deployed
to become vertical to the rear side surface of the hand-held satellite
mobile phone terminal body when it is used. The antenna deployment
element is attached to the body of the hand-held satellite mobile
phone terminal through a rotational axis so that the small antenna
attached to the antenna deployment element can be rotated after
deployment in order for its plane to become parallel with the ground
surface. Also, the hand-held satellite mobile phone terminal is
usable both in a satellite communication system and in a terrestrial
cellular communication system. For this purpose, the antenna deployment
element, batteries and circuits for satellite communication are
installed as one package, which can be folded and stored on the
rear side surface of the body of the hand-held mobile phone terminal,
and which can be removed freely so that it is replaced by another
package having the same attachment size as the one package and containing
only batteries, when the hand-held mobile phone terminal is used
in a terrestrial mobile communication system.
Mobile Phone Patent Claims
What are claimed are:
1. A hand-held satellite mobile phone terminal comprising an antenna
deployment element having an antenna attached to a distal tip area
thereof, said antenna deployment element being movable between a
first position where it is folded and stored on a rear side surface
of said hand-held satellite mobile phone terminal, and a second
position where it is deployed perpendicular with respect to the
rear side surface of said hand-held satellite mobile phone terminal
body when in use;
wherein said phone terminal is a dual mode type terminal which
is usable both in a satellite communication system and in a terrestrial
cellular communication system, said phone terminal having a first
package removably coupled to said rear side surface thereof, said
package including said antenna deployment element, batteries and
circuits for satellite communication installed as one unit, said
package being replaceable by a second package, including only batteries,
having the same attachment size as said first package.
2. A hand-held satellite mobile phone terminal comprising an antenna
deployment element which is a one-piece component having an antenna
attached to a distal tip area thereof, said antenna deployment element
being movable between a first position where it is folded and stored
on a rear side surface of said hand-held satellite mobile phone
terminal, and a second position where it is deployed perpendicular
with respect to the
rear side surface of said hand-held satellite mobile phone terminal
body when in use, and said antenna deployment element being rotatably
attached to the rear side surface of the body of said hand-held
satellite mobile phone terminal so that said antenna deployment
element is rotatable around its longitudinal axis after deployment
to said second position such that a plane of the antenna is parallel
with the ground surface.
3. A hand-held satellite mobile phone terminal comprising an antenna
deployment element having an antenna attached to a distal tip area
thereof, said antenna deployment element being movable between a
first position where it is folded and stored on a rear side surface
of said hand-held satellite mobile phone terminal, and a second
position where it is deployed perpendicular with respect to the
rear side surface of said hand-held satellite mobile phone terminal
body when in use, and said antenna deployment element being rotatably
attached to the rear side surface of the body of said hand-held
satellite mobile phone terminal so that said antenna deployment
element is rotatable around its longitudinal axis after deployment
to said second position such that a plane of the antenna is parallel
with the ground surface;
wherein said phone terminal is a dual mode type terminal which
is usable both in a satellite communication system and in a terrestrial
cellular communication system, said phone terminal having a first
package removably coupled to said rear side surface thereof, said
package including said antenna deployment element, batteries and
circuits for satellite communication installed as one unit, said
package being replaceable by a second package, including only batteries,
having the same attachment size as said first package.
4. A hand-held mobile phone terminal as claimed in claim 1 wherein
said antenna is a patch antenna.
5. A hand-held mobile phone terminal as claimed in claim 2 wherein
said antenna is a patch antenna.
6. A hand-held mobile phone terminal as claimed in claim 1 wherein
said antenna is a patch antenna.
7. A hand-held mobile phone terminal as claimed in claim 3 wherein
said antenna is a patch antenna.
8. A hand-held satellite mobile phone terminal having an elongated
body with a front side surface, adapted to be placed next to a user's
face, and a rear side surface, comprising:
an elongated antenna deployment element which is a one-piece component
having first and second opposite ends and being rotatably coupled
to said rear side surface by only a single hingedly-connected portion
which is at said first end; and
an antenna mounted on said antenna deployment element at said second
end of said antenna deployment element;
wherein when in use to deploy said antenna, said antenna deployment
element is rotated at said single hingedly-connected portion about
said at least one point such that a longitudinal axis of said antenna
deployment element is perpendicular with respect to a longitudinal
axis of said body.
Mobile Phone Patent Description
BACKGROUND OF THE INVENTION
This invention describes antenna deployment structures of a hand-held
mobile phone terminal for a satellite mobile communication system,
and a dual mode hand-held mobile phone terminal which can be used
both for a satellite mobile communication system and for a terrestrial
cellular mobile communication system.
DESCRIPTION OF THE PRIOR ART
The conventional antenna structure of a terrestrial cellular mobile
phone terminal is described as follows: a whip antenna having a
length of about one quarter wavelength is stored usually in the
body of a hand-held terminal from upside, and is stretched out when
it is in use for communication. Although the antenna gain is affected
largely by the presence of human head for such an antenna structure,
no serious problems such as communication interrupt will occur,
because 20 dB or more link margin can be obtained from a larger
field intensity with a shorter distance from a station than in a
satellite system. Fading due to multiple paths may degrade communication
quality, but this can be eased by using a diversity antenna system
where a panel type inverse F antenna is attached to a different
position than that of the whip antenna.
The conventional antenna structure of a satellite mobile phone
terminal is described in the following: as the electromagnetic wave
intensity at the ground surface is generally small in a satellite
communication system due to the load limitation for a satellite,
the antenna gain of terrestrial equipment must be large enough.
Serious problems may arise, however, in increasing the antenna gain,
in that the antenna gain and the axial ratio may be easily affected
by the presence of the user's head.
Two conventional methods to avoid this difficulty are explained
in a reference by J. E. Caballero, et Al., "Hand-held Terminal
Antennas for Personal Satellite Communications", International
Mobile Satellite Conference, Ottawa, IMSC'95, pp351-356. The antenna
structure of the one method is illustrated in FIGS. 1(a) and 1(b),
where a four-wire helical
antenna 1 is attached on the tip of a bar-shaped deployable element
5 which can be rotated along the side surface of a mobile phone
body 2. When the phone is held in a hand for use, the element should
be fixed nearly vertical to the ground, with the antenna at a higher
position than the user's head in order to avoid the influence from
the user's body. The antenna is stored at one side of the phone
body by rotating it when it is not in use. The antenna structure
of the other method is shown in FIGS. 2(a) and 2(b), where two flat
bars 7 at the each side of a phone body are deployed by rotating
180 degrees. A plate 6 with a patch antenna on it is attached near
the tips of the flat bars. When the phone is used in a user's hand,
the patch antenna plate is deployed by rotating 90 degrees so that
the antenna plane becomes nearly in parallel with the ground surface.
The antenna plate is attached aslant to the flat bars so that its
surface faces to the sky when it is in use. In this structure also,
the antenna is held at a higher position than the user's head.
Another conventional antenna structure which is used for one of
satellite mobile phone systems, Iridium System, is illustrated in
FIG. 3, where a bar antenna is attached to an upper portion of a
phone terminal body, and it is folded and stored at the side of
the body when it is not used.
SUMMARY OF THE INVENTION
As an antenna for a hand-held mobile phone terminal is generally
used near the human body, gain and axial ratio of the antenna tend
to become largely degraded by the influence of the human body, resulting
in the communication quality degradation. Additionally, using an
antenna near the human head is not favorable for guarding the human
body from electromagnetic field influence.
Terrestrial electromagnetic field intensity of a signal from a
satellite in a satellite mobile communication system is generally
weak as compared to that of a terrestrial cellular mobile communication
system, because of the satellite scale limitation due to the rocket
ability or cost, and because of the long distance between the satellite
and the ground. For this reason, and also for avoiding the influence
from a human head on antenna sensitivity patterns, it is necessary
to increase the gain of a mobile phone satellite antenna. This results
in a larger and longer rod antenna which can exceed the height of
the user's head. The necessity for accommodation of such an large
antenna inevitably leads to a larger mobile phone body. A larger
body means a heavier body, which tends to drop downwards while supported
by a user's hand, to an inconvenient position.
A dual mode mobile phone terminal which can be applied both for
a terrestrial cellular system and for a satellite system will be
widely used in a mobile satellite communication system. Most of
the users will usually employ the terrestrial system while they
will use the satellite system as complementary. That is, for example,
they will usually use the former system but will use the latter
in a special case when they will go to mountains or an isolated
island.
Such a dual mode mobile phone terminal inevitably becomes heavy,
because even if it is used in a terrestrial cellular mobile system,
it needs circuits and an antenna system for a satellite communication
system, besides those for the terrestrial system.
It is an object of the invention to solve above mentioned problems
through provision of novel methods enabling realization of a hand-held
mobile phone terminal having an antenna structure which is light
in weight, invulnerable to the influence of human head and harmless
for human head.
The hand-held satellite mobile phone terminal of the invention
is characterized in that it contains an antenna deployment element
with a small antenna attached to the tip area of the said antenna
deployment element, in that said antenna deployment element is usually
folded and stored on the rear side surface of the body of said hand-held
satellite mobile phone terminal, and in that said antenna deployment
element is deployed to become perpendicular to the rear side surface
of said hand-held satellite mobile phone terminal body when it is
used.
Another characteristic of the invention is in that the antenna
deployment element is attached to the body of the hand-held satellite
mobile phone terminal through a rotational axis so that a small
antenna attached to said antenna deployment element can be rotated
after deployment for its plane to become parallel with the ground
surface.
A further characteristic of the invention resides in that said
hand-held satellite mobile phone terminal can be used as a dual
mode hand-held mobile phone terminal which is usable both in a satellite
communication system and in a terrestrial cellular communication
system. Said antenna deployment element, batteries and circuits
for satellite communication are installed as one package as a "satellite
pack", are folded and stored on the rear side surface of the
body of said hand-held mobile phone terminal, and can be removed
freely so that it is replaced by another package, a "terrestrial
pack", having the same attachment size as said satellite pack
and containing only batteries, when said hand-held mobile phone
terminal is used in a terrestrial mobile communication system.
A further characteristic of the invention is in that said small
antenna is a thin flat patch antenna, said deployment element is
flat panel shaped and said thin flat patch antenna can be attached
to the tip. A thin flat patch antenna is mounted on the tip of an
antenna plate (a deployment element) which is folded and stored
on the rear side surface of the satellite pack of a dual mode mobile
phone terminal, or on the rear side surface of the body of a mobile
phone terminal only for satellite communication. When the mobile
phone terminal is in use, the deployment element is first deployed
up to 90 degrees from its stored position, then said deployment
element is rotated, considering the slant angle of said mobile phone
terminal to the ground surface, in order that the antenna plane
of said patch antenna attached to said deployment element can become
parallel with the ground surface.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1(a) and 1(b) describe a structure example of the antenna
portion of a conventional hand-held mobile phone terminal for a
mobile satellite communication system.
FIGS. 2(a) and 2(b) describe another structure example of a conventional
hand-held mobile phone terminal for a mobile satellite communication
system.
FIG. 3 is also another structure example of a conventional hand-held
mobile phone terminal for a mobile satellite communication system.
FIGS. 4(a) and 4(b) show a preferred embodiment of antenna deployment
structures for a hand-held mobile phone terminal of the invention.
FIGS. 5(a) and 5(b) depict a preferred embodiment of structures
for a dual mode hand-held mobile phone terminal of the invention.
FIGS. 6(a) and 6(b) describe a preferreed embodiment of antenna
directionality and antenna excitation pattern for a patch antenna
suitable for satellite communication using a geostationary satellite.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment of the invention will be explained hereinafter
referring to drawings FIGS. 4(a), 4(b), 5(a) and FIG. 5(b).
FIG. 4(a) shows a basic configuration of a hand-held mobile phone
terminal of the invention for a satellite communication system.
Said hand-held mobile phone terminal 10 in the figure is having
at the rear side surface 11 of its body an antenna deployment element
12 which has a small patch antenna attached to its tip portion.
Said deployment element 12 is usually folded and stored at the rear
side surface 11 of said hand-held mobile phone terminal body, and
when it is in use, it is deployed to become perpendicular to the
rear side surface 11 of the body of said hand-held mobile phone
terminal 10, as is shown by the arrow "a" in FIG. 4(b).
Said antenna deployment element 12 comprises, as is shown in FIG.
4(b), a small thin patch antenna 13, a panel which supports said
patch antenna 13 and a power feeder portion although it is not shown
in the figure. A human head is illustrated as 14 in FIG. 4(b).
The hand-held phone terminal is mostly used in a position where
the angle between the longitudinal direction of the terminal body
and a perpendicular direction is about 60 degrees. Consequently,
said patch antenna 13 should be rotated at the rear side of the
mobile phone terminal body in the direction shown by the arrow "b"
in the FIG. 4(b), in order that the patch antenna faces the zenith.
For this purpose, the folded and stored antenna which is shown in
FIG. 4(a) is deployed before beginning satellite communication,
according to the sequence described below.
First, the deployment element 12 is deployed in the direction shown
by the arrow "a" in FIG. 4(b), in order that it becomes
perpendicular to the rear side surface 11 of said hand-held mobile
phone terminal body. Then, the deployed deployment element is rotated
several tens of degrees around its longitudinal axis and is fixed
at that position, considering the slant angle of said mobile phone
terminal body to the ground surface, in order that the plane of
said deployment element becomes parallel with the ground surface.
The rotation of the deployment element and the fixing of its position
in parallel with the ground surface should be triggered through
pushing a button by a finger of the user's hand which holds the
hand-held mobile phone terminal. It is preferable that the rotation
and fixing structure is such that the plane of the deployment element
becomes parallel with the ground surface regardless of which side
of the user's head the hand-held mobile phone terminal is on. By
attaching the antenna at an appropriate tip position of the deployment
element, it is possible for the antenna not to be affected by the
presence of the user's head.
FIGS. 5(a) and 5(b) show a preferable embodiment example of the
invention applied to a dual mode hand-held mobile phone terminal
for a satellite mobile communication system. If the mobile phone
terminal of the invention is used in a satellite communication system,
said mobile phone terminal comprises a main body which has the same
function as a conventional terrestrial cellular mobile phone terminal
from which a battery portion is removed, and a satellite pack which
is attached to the portion of the main body from where the battery
portion was removed, as FIG. 5(a) shows. The satellite pack has
an attachment surface size which is the same as that of a terrestrial
pack which contains only batteries for use in a terrestrial communication
system. The two packs can be replaced by each other according to
the application purpose. The satellite pack includes batteries,
satellite communication circuits and an antenna for satellite communication.
The deployment element 19 which is attached to the satellite pack
has a similar structure as the one illustrated in FIGS. 4(a) and
4(b), comprising a deployment element 19 stuff which supports an
antenna (an antenna plate), a thin flat patch antenna 20 and a power
feeding portion which is not shown in the figure.
Deployment procedure for this embodiment example is similar as
is illustrated in FIG. 4(b). That is, before beginning satellite
communication, the folded and stored antenna is deployed according
to the procedure described in the following.
First, the deployment element 19 is deployed in the direction shown
by the arrow "a" in FIG. 5(b), in order that it becomes
vertical to the rear side surface of the hand-held mobile phone
terminal body. Then, the deployed deployment element 19 is rotated
several tens of degrees around its longitudinal axis and is fixed
at that position as shown in FIG. 5(b), considering the slant angle
of said mobile phone terminal body to the ground surface so that
the plane of said deployment element is parallel with the ground
surface.
The hand-held mobile phone terminal of the invention that -has
the structure stated above can be used for both a geostationary
and a geocirculating satellite communication system. Especially
in a geostationary system, the antenna gain can be enhanced by using
a conical beam as illustrated in FIG. 6(a). For example, when the
satellite orbit position is on 140 degrees of east longitude and
the service area is assumed to cover the whole Japan islands, the
elevation angle to look up to the satellite from the ground is about
between 36 degrees and 60 degrees. Considering that the antenna
can be fixed to be in parallel with the ground, a patch antenna
for circular polarization which has a directionality characteristic
so-called as cone beams is more suitable than ordinary type antennas
of which gain becomes maximum in the zenith direction. The cone
beam directionality as illustrated in FIG. 6 (a) can be easily realized
by exciting TM.sub.21 or TM.sub.11 mode for a circular patch antenna.
FIG. 6(b) shows an example of TM.sub.21 mode excitation.
For a hand-held mobile phone terminal which is used only for a
satellite communication system without any need for connection to
a terrestrial cellular communication system, it is more suitable
to implement an antenna deployment structure similar to the one
which is attached to the rear side of the satellite pack, on the
rear side of the hand-held mobile phone terminal body, than to use
the removable satellite pack. If a user wants to use usually only
the terrestrial cellular communication system, the satellite pack
can be removed and replaced by the original battery pack (terrestrial
pack), so as to reduce the weight of the terminal. Antenna structure
for terrestrial communication can be the same as the conventional
one.
As the deployment element of the invention is deployed to be stretched
out aside at the rear side of the hand-held mobile phone terminal
body and the patch antenna is attached at the tip of the deployment
element, said patch antenna is deployed accordingly to be spaced
from the user's head. Because of this particular antenna structure,
degradation in antenna gain or axial ratio can be kept very small
and the effect of electromagnetic field can be reduced to protect
the human body, as compared to conventional structures wherein an
antenna is used near the human head.
In addition to the above, the size of the mobile phone terminal
of the invention when the antenna is folded and stored can be made
smaller than conventional ones which use a bar shaped antenna, because
the deployment element of the invention is panel shaped and the
antenna attached to it is a thin flat patch type. Also, by using
a hand to support the mobile phone terminal body at the deployment
element joint, it becomes easier for a user to prevent the mobile
phone terminal slipping down by its own weight.
When the mobile phone terminal of this invention is used as a dual
mode mobile phone terminal and if it is usually used only in a terrestrial
mobile phone system, the weight of the terminal can be greatly reduced
by replacing the satellite pack with the terrestrial pack which
only includes batteries. Weight of unnecessary circuits for satellite
communication and the antenna can be excluded by this replacement,
which is quite important for a practical hand-held terminal.
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