Communications: radio wave antennas – Antennas – Spiral or helical type
Reexamination Certificate
2001-06-14
2003-02-04
Wong, Don (Department: 2821)
Communications: radio wave antennas
Antennas
Spiral or helical type
C343S702000, C343S901000
Reexamination Certificate
active
06515637
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to an antenna for a mobile communication system and a fabrication method thereof, and in particular to an antenna for a mobile communication system and a fabrication method thereof which are capable of enhancing a band width of a high frequency signal and simplifying an assembling process of an antenna by improving the structure of a helical antenna in a mobile communication system.
2. Background Art
Generally, an antenna is used for performing a wireless communication. Namely, a high frequency signal is applied from a modulator to an antenna, and a high frequency signal transmitted in the air is received through the antenna.
In order to enhance a transmission and receiving characteristic of an antenna, an impedance of an antenna and an impedance of a transceiver are matched in accordance with a high frequency signal which is transmitted and received for thereby preventing unnecessary emission and loss.
In addition, the antenna used for the mobile communication system is formed of a helical antenna and a rod antenna in an integrated construction. In the case that the rod antenna is received, the helical antenna is operated. In the case that the rod antenna is extracted, the rod antenna and helical antenna are engaged in parallel. The entire operation of the antenna is performed by the rod antenna.
In the above described antenna structure, the helical antenna includes a spring formed by winding a wire.
FIG. 1
is a view illustrating an antenna installed in a conventional wireless communication system. Here, reference numeral
10
represents a body of a mobile communication system, and
20
represents an antenna unit installed in the body
10
for transmitting and receiving a high frequency signal therethrough.
The antenna unit
20
includes a knob
21
by which the antenna is extracted and retracted by holding the same, an insulation portion
22
, a helical antenna
23
having a spring
25
which is operated when the antenna engaged to the body
10
of the mobile communication system is received, and a Ni—Ti wire
24
engaged in parallel with the helical antenna
23
when extracting the antenna and functioning as a rod antenna.
FIG. 2
is a view illustrating a helical antenna
23
in the antenna of FIG.
1
. As shown therein, the helical antenna
23
includes a spring
25
formed of a wire having a circular cross section and diameter, and a metal rod
26
engaged with the spring
25
, so that the lower portion of the spring
25
is wound onto the metal rod
26
by one turn.
In the conventional antenna, since the return loss which occurs when a high frequency signal is transmitted is about 7.5 dB, and the band width a coverage in the antenna is small, the communication quality is decreased in the case that the antenna is touched by a hand of a human, and there is a certain variation in the frequency at the time of communication. In addition, the conventional antenna has about 23.0&OHgr; impedance which is lower than 50&OHgr; of a reference value for thereby causing a mismatching. In addition, in the conventional art, the standing wave ratio is about 2.3 larger than the reference value 1, so that the power return ratio is about 15.5%. Therefore, the power loss of the antenna is increased.
DISCLOSURE OF THE INVENTION
Accordingly, it is an object of the present invention to provide an antenna for a mobile communication system and a fabrication method thereof which are capable of obtaining a lower return loss by improving the structure of a spring installed in a helical antenna, improving a communication quality even when an antenna is touched by a hand of a human or there is a certain variation in the frequency at the time of communication.
In order to achieve the above objects, there is provided an antenna for a mobile communication system which includes a spring of the helical antenna formed in such a manner that a wire having a certain diameter is pressed for thereby forming a plate shaped wire having a certain width, and the plate shaped wire having a certain width is wound by a certain number of turns.
In order to achieve the above objects, there is provided a fabrication method of an antenna for a mobile communication system which includes a first step for pressing a wire having a certain diameter, forming a plate shaped wire having a certain width, winding the plate shaped wire having a certain width by a certain number of turns and forming a spring of a helical antenna, a second step for inserting and soldering an upper end of a metal rod to a lower portion of the spring formed of a plate shaped wire and fixing the same, a third step for insert-molding a pipe in such a manner that a certain space is formed in the center portion in the spring and metal rod fixed in the second step and inserting a bobbin of the pipe, and a fourth step for inserting a + cutting portion to a lower portion of the metal rod and inserting the rod antenna in the space portion of the center portion.
REFERENCES:
patent: 4442438 (1984-04-01), Siwiak et al.
patent: 5650789 (1997-07-01), Elliott et al.
patent: 5861859 (1999-01-01), Kanayama et al.
patent: 0419900 (1991-04-01), None
patent: WO 98 56072 (1998-12-01), None
Chen Shih-Chao
Coleman Henry D.
Sapone William J.
Sudol R. Neil
Wong Don
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