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Mobile Phone Patent Abstract
A built-in multi-band mobile phone antenna includes: a meandering
conductive body having a signal feeding point, and first and second
meandering conductive portions disposed at two sides of the signal
feeding point; a conductive flat first radiating plate in electrical
connection with the first meandering conductive portion and tuned
to a low frequency range; an elongated conductive flat second radiating
plate in electrical connection with the second meandering conductive
portion and a grounding point and tuned to a high frequency range;
and a conductive flat parasitic plate in electrical connection with
the grounding point so as to widen the bandwidth of the antenna.
The conductive body, the first and second radiating plates, and
the parasitic plate define cooperatively a plate-shaped accommodating
space thereamong for receiving a plate-shaped electronic element.
Mobile Phone Patent Claims
We claim:
1. A built-in multi-band mobile phone antenna comprising: a meandering
conductive body having a first meandering conductive portion, a
second meandering conductive portion, and a signal feeding point
disposed between said first and second meandering conductive portions;
a conductive flat first radiating plate spaced apart from said conductive
body, said first radiating plate being in electrical connection
with said first meandering conductive portion of said conductive
body and tuned to a low frequency range; an elongated conductive
flat second radiating plate spaced apart from said conductive body,
said second radiating plate being in electrical connection with
said second meandering conductive portion of said conductive body
at one end and being adapted to be connected electrically to a grounding
point at the other end, said second radiating plate being tuned
to a high frequency range that is different from said low frequency
range; and a conductive flat parasitic plate adapted to be in electrical
connection with the grounding point so as to widen bandwidth of
said antenna, all of said conductive body, said first and second
radiating plates, and said parasitic plate defining cooperatively
a plate-shaped accommodating space thereamong.
2. The built-in multi-band mobile phone antenna as claimed in claim
1, further comprising a third meandering conductive portion that
is in electrical connection with said second radiating plate and
that is adapted to be in electrical connection with the grounding
point.
3. The built-in multi-band mobile phone antenna as claimed in claim
2, further comprising a fourth meandering conductive portion that
is in electrical connection with said parasitic plate and that is
adapted to be in electrical connection with the grounding point.
4. The built-in multi-band mobile phone antenna as claimed in claim
3, wherein said first, second, third, and fourth meandering conductive
portions are coplanar, and said parasitic plate is coplanar with
said first and second radiating plates.
5. The built-in multi-band mobile phone antenna as claimed in claim
1, wherein said low frequency range includes a 900 MHZ frequency
band corresponding to a GSM frequency band.
6. The built-in multi-band mobile phone antenna as claimed in claim
1, wherein said high frequency range includes a 1800 MHZ frequency
band corresponding to a DCS frequency band, and a 1900 MHZ frequency
band corresponding to a PCS frequency band.
7. The built-in multi-band mobile phone antenna as claimed in claim
1, further comprising a printed circuit board that is fixed within
said accommodating space.
8. The built-in multi-band mobile phone antenna as claimed in claim
7, wherein said printed circuit board has first and second side
surfaces that are opposite to each other, said conductive body being
disposed on said first side surface of said printed circuit board,
said first and second radiating plates and said parasitic plate
being disposed on said second side surface of said printed circuit
board.
9. The built-in multi-band mobile phone antenna as claimed in claim
8, further comprising a third meandering conductive portion, which
is disposed on said first side surface of said printed circuit board,
which is in electrical connection with said second radiating plate,
and which is adapted to be in electrical connection with the grounding
point.
10. The built-in multi-band mobile phone antenna as claimed in
claim 9, further comprising a fourth meandering conductive portion,
which is disposed on said first side surface of said printed circuit
board, which is in electrical connection with said parasitic plate,
and which is adapted to be in electrical connection with the grounding
point.
11. The built-in multi-band mobile phone antenna as claimed in
claim 10, wherein said low frequency range includes a 900 MHZ frequency
band corresponding to a GSM frequency band.
12. The built-in multi-band mobile phone antenna as claimed in
claim 11, wherein said high frequency range includes a 1800 MHZ
frequency band corresponding to a DCS frequency band, and a 1900
MHZ frequency band corresponding to a PCS frequency band.
Mobile Phone Patent Description
BACKGROUNDING OF THE INVENTION
1. Field of the Invention
This invention relates to multi-band antenna, and more particularly
to a built-in multi-band mobile phone antenna.
2. Description of the Related Art
Advancements in electronic communication technology have led to
a reduction in the overall sizes of mobile phones, personal digital
assistants (PDA), and the like. Built-in type mobile phone antennas
are attractive accordingly, and include planar inverted F antennas
(PIFA), microstrip antennas, etc.
Referring to FIG. 1, a conventional PIFA 5 is shown to include
a conductive flat radiating plate 51 that defines a gap 52 and that
has a first plate portion 511, a second plate portion 512, a signal
feeding point (F) that is disposed between the first and second
plate portions 511, 512, and a grounding point (G) that is adjacent
to the signal feeding point (F). The radiating plate 51 is connected
electrically to a coaxial cable 54 at the signal feeding point (F),
and to a grounding plate 6 at the grounding point (G) via a conductive
grounding leg 55. Four dielectric legs 56 are fixed on the grounding
plate 6 for supporting four corners of the radiating plate 51. The
conventional PIFA can operate in a 900 MHZ frequency band and a
1900 MHZ frequency band so that the bandwidth of the PIFA is relatively
narrow, thereby resulting in poor signal communications. A parasitic
element 7 (see FIG. 2) can be added to the PIFA so as to widen the
bandwidth of the 1800 MHZ frequency band, thereby facilitating the
signal communications. However, the bandwidth of the 900 MHZ frequency
band still cannot be widened.
SUMMARY OF THE INVENTION
The object of this invention is to provide a compact built-in multi-band
mobile phone antenna, which can overcome the drawbacks associated
with the prior art.
According to this invention, a built-in multi-band mobile phone
antenna includes: a meandering conductive body having a signal feeding
point, and first and second meandering conductive portions disposed
at two sides of the signal feedingpoint; a conductive flat first
radiating plate in electrical connection with the first meandering
conductive portion and tuned to a low frequency range; an elongated
conductive flat second radiating plate in electrical connection
with the second meandering conductive portion and a grounding point
and tuned to a high frequency range; and a conductive flat parasitic
plate in electrical connection with the grounding point so as to
widen the bandwidth of the antenna. The conductive body, the first
and second radiating plates, and the parasitic plate define cooperatively
a plate-shaped accommodating space thereamong for receiving a plate-shaped
electronic element, e.g. a printed circuit board.
The low frequency range includes a 900 MHZ frequency band corresponding
to a GSM frequency band, the bandwidth of which is widened by the
parasitic plate. The high frequency range includes a 1800 MHZ frequency
band corresponding to a DCS frequency band, and a 1900 MHZ frequency
band corresponding to a PCS frequency band because the first and
second meandering conductive portions can widen the bandwidth of
the 1800 MHZ frequency band so as to transmit and receive a 1900
MHZ frequency signal.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features and advantages of this invention will
become apparent in the following detailed description of the preferred
embodiments of this invention, with reference to the accompanying
drawings, in which:
FIG. 1 is a fragmentary perspective view of a conventional PIFA;
FIG. 2 is a fragmentary perspective view of another conventional
PIFA modified from that of FIG. 1 by adding a parasitic element;
FIG. 3 is a perspective view of a first preferred embodiment of
a built-in multi-band mobile phone antenna according to this invention;
and
FIG. 4 is a side view of a second preferred embodiment of a built-in
multi-band mobile phone antenna according to this invention, which
is incorporated into a mobile phone.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Before the present invention is described in greater detail in
connection with the preferred embodiments, it should be noted that
similar elements and structures are designated by like reference
numbers throughout the entire disclosure.
Referring to FIG. 3, a first preferred embodiment of a built-in
multi-band mobile phone antenna 1 according to this invention is
shown to include a meandering conductive body 10, a conductive flat
first radiating plate 11, and an elongated conductive flat second
radiating plate 12, and a conductive flat parasitic plate 13.
The conductive body 10 has a first meandering conductive portion
101, a second meandering conductive portion 102, and a signal feeding
point 3 disposed between the first and second meandering conductive
portions 101, 102.
The first radiating plate 11 is spaced apart from the conductive
body 10, is connected electrically to the first meandering conductive
portion 101 of the conductive body 10 via a conductive coupling
leg 81, and is tuned to a low frequency range, which includes a
900 MHZ frequency band corresponding to a GSM frequency band.
The second radiating plate 12 is spaced apart from the conductive
body 10, is connected electrically to the second meandering conductive
portion 102 via a conductive coupling leg 82 at one end and to a
grounding point 4 via a conductive coupling leg 83 and a third meandering
conductive portion 103 at the other end, and is tuned to a high
frequency range, which includes a 1800 MHZ frequency band corresponding
to a DCS frequency band, and a 1900 MHZ frequency band corresponding
to a PCS frequency band. Note that the second and third meandering
conductive portions 102, 103 and the second radiating plate 12 constitute
a loop antenna, and can lead to an increase in the bandwidth of
the 1800 MHZ frequency band so as to transmit and receive a 1900
MHZ frequency signal.
The parasitic plate 13 is connected electrically to the grounding
point 4 via a conductive coupling leg 84 and a fourth meandering
conductive portion 104, and serves to widen the bandwidth of the
900 MHZ frequency band.
The first, second, third, and fourth meandering conductive portions
101, 102, 103, 104 are coplanar, and the parasitic plate 13 is coplanar
with the first and second radiating plates 11, 12 so as to define
a plate-shaped accommodating space 2 thereamong for receiving a
plate-shaped electronic element (not shown).
FIG. 4 shows a second preferred embodiment of this invention, which
is incorporated into a mobile phone 90 and which is similar to the
first preferred embodiment in construction. In this embodiment,
a printed circuit board 9 is fixed within the accommodating space
2. The board 9 has first and second side surfaces 91, 92. The conductive
body 10, and the third and the fourth meandering conductive portions
103, 104 are disposed on the first side surface 91 of the board
9. The first and second radiating plates 11, 12, and the parasitic
plate 13 are disposed on the second side surface 92 of the board
9. In this embodiment, the coupling legs 81, 82, 83, 84 (see FIG.
3) are replaced with four metallic diaphragms (not shown), which
extend through holes (not shown) in the board 9. As such, both the
antenna of this invention and a radio frequency circuit (not shown)
for controlling transmission and reception of an electromagnetic
wave can be installed on the printed circuit board 9. As such, it
is possible to mass-produce the mobile phones 90 with relative ease.
With this invention thus explained, it is apparent that numerous
modifications and variations can be made without departing from
the scope and spirit of this invention. It is therefore intended
that this invention be limited only as indicated by the appended
claims. |