1. Field of the Invention
The present invention relates to an antenna structure for a TPMS (Tire pressure Monitoring System) transmitter to effectively increase the length of antenna and enhance the efficiency.
2. Description of the Prior Art
After a vehicle has driven for a time or been solarized and been low temperature at night, the vehicle easily produce the leak pressure to cause the pressure value lower the standard. As far as the driving safe is concerned, the leak pressure has the latent danger especial for high speed to break due to the tire pressure not enough, for example.
A prior TMPS transmitter includes a transmitter and a receiver set on or around the appearance of bearing to observe the signal form the transmitter set in the tire any time and to understand the pressure and temperature condition of tire. However, as far as the transmitter is concerned, the main types are internal transmitter and external transmitter, wherein the internal transmitter usually is set in the tire and fixed on the tire frame and the external transmitter set on the valve outside the tire. The module main includes an antenna, a transmitter IC, a micro-processor, a temperature and pressure sensor and a battery shown as in
However, the framework, which is the antenna structure in printed circuit board (PCB) shown as the
Another prior art shown as in
The advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of the present invention.
In order to solve the foregoing problems, one object of the present invention is to provide an antenna structure for a TPMS transmitter. A TPMS transmitter couples with a valve so that a spiral coil within the TPMS transmitter can be electrically connected to a conduct body of the valve to get a specific resonance frequency. Hence, the length of the antenna structure may be increased effectively and the radiation efficiency may be raised.
One object of the present invention is to provide an antenna structure for a TPMS transmitter. By increasing the length of antenna the radiation efficiency may be enhanced, the power consumption may be lowered, and then the reduction lifetime of battery may further be improved.
To achieve the objective mentioned above, one embodiment of the present invention of an antenna structure for a TPMS transmitter includes a transmitter module and a spiral coil electrically connected with the transmitter module, wherein the spiral coil within the TPMS transmitter is electrically connected to a conductive body of a valve by screwing method to form the antenna structure for the TPMS transmitter.
To achieve the objective mentioned above, another embodiment of the present invention of an antenna structure for a TPMS transmitter includes: a printed circuit board electrically connected to a battery; a support tube covered the printed circuit board and the battery; a first engaged portion set at an end of the support tube and protruding from the support tube; a coil around the circumference of the support tube to form a portion of an antenna structure, and electrically connected to the first engaged portion and the printed circuit board; a housing covering the coil, the support tube and the printed circuit board to expose the first engaged portion; and a valve with an insulating body, a conductive body and a second engaged portion, wherein the insulating body covers the conductive body; the conductive body penetrates through the insulating body to form another portion of the antenna structure; and the second engaged portion couples with the conductive body and protrudes from the insulating body; whereby screwing the first engaged portion and the second engaged portion to electrically connect the coil with the conductive body.
The basic principle can be known by the principle of the transmission line.
Under the circumstance of open at the receiving end, the input impedance of the transmission line shows the capacitance when the length of the transmission line is shorter than the quarter wavelength. Based on general length of valve about four cm, but the quarter wavelength is 24 and 17 cm in the frequency (315/433 MHz) applied for TPMS, hence, the capacitance exists. Besides, from the basic principle of antenna knows the resonant frequency is produced while the reactance equals zero. By producing the inductance from the spiral coil within the TPMS transmitter. The inductance offset the capacitance of the valve each other to reach the target of resonance frequency applied for TPMS.
The foregoing aspects and many of the accompanying advantages of this invention will become more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
a is a block diagram illustrating the conventional TPMS transmitter;
b is a three-dimensional diagram illustrating the conventional antenna structure for a TPMS transmitter;
c is a three-dimensional diagram illustrating the conventional antenna structure for a TPMS transmitter;
a, and
The detailed explanation of the present invention is described as following. The described preferred embodiments are presented for purposes of illustrations and description, and they are not intended to limit the scope of the present invention.
First, please refer to
Next, please refer to the
Continuously, please refer to
Continuously above description, the first engaged portion 130 may totally protrude from the housing 150 or partially protrude from the housing 150 to conveniently screw the first engaged portion 130 with the second engaged portion 220. In one embodiment, the first engaged portion 130 may further include a screw nut structure and the second engaged portion 220 may be an eye bolt structure matching the screw nut structure; besides, the first engaged portion 130 may also be an eye bolt structure, and the second engaged portion 220 may be a matching structure such as a screw nut structure. But it may be understood that only if the structure such as the first engaged portion 130 engaged with the second engaged portion 220 by screwing method is it involved in the scope of the present invention.
Besides, from the transmission line principle can know that under the circumstance of open at the receiving end, the input impedance of the transmission line shows the capacitance when the length of the transmission line shorter than the quarter wavelength. Based on general length of valve about four cm, the capacitance exists in the frequency (315/433 MHz) applied for TPMS. In one embodiment, the coil 122 can be spiral coil 120 to produce inductance. After the first engaged portion 130 matches with the second engaged portion 220 of the valve 200, the capacitance of the valve 200 may balance the inductance of the coil 122 each other to reach the target of resonance frequency applied for TPMS.
According to the description above, one of the characteristic of the present invention is to produce the inductance by coil offsetting the capacitance of the valve to reach the target of resonance frequency applied for TPMS. Besides, the screwing structure at the coil and the screwing structure of the valve can also be designed that the eye bolt structure of the valve matching the screw nut of structure at the coil by user. Therefore, the structure of antenna can set in internal transmitter or external transmitter and the capacity is high in substantiation.
To sum up the description above, the present invention provides an antenna structure for TPMS transmitter. A TPMS transmitter couples with a valve and a spiral coil within the TPMS transmitter can be electrically connected to a conduct body of the valve to get a specific resonance frequency. Hence, the length of the antenna structure can be increased effectively and the radiation efficiency can be raised. Moreover, by increasing the length of antenna to enhance the radiation efficiency and to lower the power consumption, the reduction lifetime of battery is further improved.
While the invention is susceptible to various modifications and alternative forms, a specific example thereof has been shown in the drawings and is herein described in detail. It should be understood, however, that the invention is not to be limited to the particular form disclosed, but to the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the appended claims.
Number | Date | Country | Kind |
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96139262 A | Oct 2007 | TW | national |
Number | Name | Date | Kind |
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4737760 | Huang et al. | Apr 1988 | A |
5040562 | Achterholt | Aug 1991 | A |
6340929 | Katou et al. | Jan 2002 | B1 |
7619509 | Tanaka | Nov 2009 | B2 |
Number | Date | Country | |
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20090102731 A1 | Apr 2009 | US |