GPS receiving antenna for cellular phone

A GPS receiving antenna for cellular phone is configurated into a L-shaped frame, a Y-shaped frame, or a U-shaped frame so as to achieve the best capturing effect of the radio wave radiated from the satellite. It is not necessary to use materials of specially high dielectric constant for fabrication of these antennas so that the production cost can be minimized and fabrication process can be simplified (FIG. 2).

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a GPS (global positioning system) receiving antenna for cellular phone, and more particularly, to specially constructed L-shaped, Y-shaped, and U-shaped receiving antennas for cellular phone capable of most effectively abstracting energy of the radio wave from the satellite, and the above-mentioned antennas can be fabricated easily with a reduced production cost.

2. Description of the Prior Art

According to USE-911 regulations, the cellular phone is obligated to have positioning function, and one of the most well-known positioning system is GPS wherein a cellular phone is equipped with a receiving antenna capable of receiving radio wave signals radiated from the satellite.

For smoothly receiving radio wave signals, a receiving antenna has to bring into consideration the following factors:1. The wavelength of the received radio signal is about 20 cm. If a ¼ wavelength antenna is to be used, the required length is 5 cm.2. The capturing pattern of the receiving antenna should be upwardly directed to the sky for abstracting energy of the radio wave from the satellite so as to eliminate any possible dead angle.3. In view of the fact that the field distribution under the satellite transmitting antenna is in a clockwise circular polarization pattern, the receiving antenna shall be configurated to match this pattern so as to effectively abstract energy of the radio wave radiated from the satellite antenna. Should the antenna be configurated to match the linear polarization, the receivable wave energy will be halved. As it is well known, the radio wave energy radiated from the satellite antenna is very weak, so that using an unmatched receiving antenna for the cellular phone may result in failing to catch the coming signal successfully.Accordingly, for a remedy to afore-mentioned defect, a high dielectric constant ceramic material is employed to form into a patch-receiving antenna for the cellular phone. In fact, the configuration of a patch antenna is suitable for upwardly directing to capture the circularly polarized clockwise spinning radio wave. In addition, the driftage of the received signals never happens to the receiving patch antenna because the ceramic is insensitive to temperature variation.There are several types of patch antenna that have been used for the cellular phone as shown inFIG. 1aandFIG. 1b.Referring toFIG. 1a,the receiving antenna is equipped on the rear housing surface of the phone. It is advantageous that the gain of the receiving antenna will be considerably high due to both large antenna size and grounding area thereof, and can be fabricated with a simple process. However, by equipping the receiving antenna only on the rear housing surface of the phone causes acceptable radio wave energy radiated from the satellite to be limited to that arriving at the rear housing surface only and leaving the front housing surface dummy. Although the top portion of the antenna facing to the satellite can receive the linearly polarized signals, yet the effect is not significant.Referring toFIG. 1b,the receiving antenna is equipped on a part of top housing surface of the cellular phone. By doing so, unmatching problem as that mentioned in the above example is solved by abstracting polarized radio wave energy downwardly radiated from the satellite. However, a material of very high dielectric property must be selected to construct the receiving antenna which is deemed to be equipped on so narrow top surface area that having a width less than 10 mm. As a result, the antenna power loss is increased, and its gain is reduced. Besides, a highly precise technology is required for fabricating such a small-sized antenna that results in a poor yield.Aiming at the above-depicted defects, the present invention is to propose a newly developed GPS receiving antenna for cellular phone capable of rectifying the above depicted defects and operating effectively and sensitively to receive the radio signal from the satellite.

SUMMARY OF THE INVENTION

The present invention is disclosed for overcoming the aforesaid shortcomings inherent to the prior arts.

Accordingly, it is an object of the present invention to provide a newly developed GPS receiving antenna for cellular phone capable of constantly aiming at the radio wave field radiated from the satellite so as to match with the field polarization pattern either the cellular phone body is placed horizontally or vertically.

It is another object of the present invention to provide a GPS receiving antenna for cellular phone capable of abstracting energy of the radio wave from the satellite in the most efficient way.

It is one more object of the present invention to provide a GPS receiving antenna for cellular phone capable of maintaining the effective wave capturing area on the antenna body so as to increase the gain of the antenna, and the antenna can be fabricated easily.

To achieve these and other objects described above, the antenna of the present invention is constructed in L, Y, and U-shaped frame type structure and attached to the relevant surface portion of the cellular phone housing without requiring use of materials of high dielectric strength.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Two examples of conventional GPS receiving antenna for cellular phone shown inFIGS. 1aand1bhave been discussed with respect to their merits and disadvantages in the foregoing paragraphs. Therefore, it is not necessary to repeat herein.

FIG. 2is a schematic view in a first embodiment of the present invention. It is shown that a GPS receiving antenna for cellular phone is formed of a L-shaped frame20a, and it is further divided into two parts. One is covering on the top part11of a phone body10offset to one side (hatched lines portion), while the other is covering down from the first part on the corresponding upper rear housing surface12. As shown inFIG. 2, W1denotes the width of the first part covering on the top surface11, and W2is the vertical width of the second part covering on the upper rear housing surface12. Therefore, W1+W2is the total width of the L-shaped frame20acovering the top surface11of the phone body10. As W1which is smaller than W, the width of the top part11, can be calculated by trail and error such that the area of the L-shaped frame20acovering on top surface11of the phone body10is defined at a relevant value with reference to the dielectric loss and the properties of the material used thereby keeping the aiming direction of the receiving antenna is fully in match with the polarized pattern of the radiation radio wave from the satellite so as to abstract energy of the radio wave in the most efficient way.

FIGS. 3aand3bare both schematic views in a second embodiment of the present invention. In this embodiment, the GPS receiving antenna is formed in a Y-shaped frame20bwhich is an extended form of the L-shaped frame20aby adding an extra leg. The Y-shaped frame20bcovers the phone body10on the top part11, the rear part12, and an additional side part13, all occupy the upper corner portion of the phone body10. The structure of the Y-shaped frame20bis so constructed that it is well suitable for capturing the circularly polarized radio wave signals radiated from the satellite. Moreover, a favorable matching effect can be obtained by relevantly adjusting the value of W1, W2, and W3.

FIG. 4is a schematic view of a third embodiment of the present invention. In this embodiment, the GPS receiving antenna is formed into a U-shaped frame20c,wherein W1+W2+W3is the width of the U-shaped frame20ccovering the phone body10and W1is the width, which covers on the top surface11thereof. It is well known that a U-shaped receiving antenna is a preferably configurated antenna to capture the circularly polarized radio wave signal radiated from the satellite. Besides, by keeping total length L (W1+W2+W3) of the U-shaped frame20c,a fixed value and varying the values of W1, W2, and W3, the dimension for the U-shaped frame20cwhich can work most efficiently can be determined.

It is understood from the foregoing description that the L-shaped, Y-shaped, and U-shaped frame type receiving antennas for cellular phone are workable most efficiently in BPS, and such simple structures are easy to fabricate with minimized production cost through quick fabrication process.

Although the invention has been described in terms of preferred embodiments, it is apparent that numerous variations and modifications may be made without departing from the true spirit and scope thereof, as set forth in the following claims.