Ceramic chip antenna

A ceramic chip antenna for transmitting and receiving wireless signals. The antenna includes a substrate and a conductor. The substrate is made of sintered ceramic material with a low dielectric loss and a high dielectric constant. A pair of concavities is cut from both longitudinal ends of the substrate. The conductor is made of metal with a high Q factor as well as a good anti-oxidization property, being formed on surfaces of the substrate by means of mask etching or printing technology. The conductor has a circuit portion disposed on surfaces of the substrate in a meandered or helical manner, and two conducting electrodes disposed at the two concavities of the substrate and connected by the circuit portion.

BACKGROUND OF THE INVENTION

The present invention relates in general to a ceramic chip antenna, and more particularly, to a high efficiency, small-sized laminated ceramic antenna that is capable of improving radiating efficiency as well as being quickly and finely adjusted for applications in various different electronic products.

Electronic products such as mobile phones, personal digital assistants, globe positioning systems, and wireless local area networks transmit and receive signals by means of a small-sized antenna installed therein. The communication qualities of these electronic products are decided by the design and manufacture of their antennas. A good design and manufacture method of an antenna can ensure the electronic products an enhancement of their communication quality. Accordingly, persons skilled in the art have endeavored to perfect the chip antenna and various prior art patents are granted.

Taiwan patent number 543939 discloses a miniaturized thin plate type wireless transmission antenna that comprises a ceramic substrate on which an antenna conductor is formed.

Taiwan patent number 518801 discloses a chip antenna and manufacturing method of the same. The chip antenna comprises an antenna conductor, and a dielectric chip that stacks on a portion of the antenna conductor. An exposed portion of the antenna conductor, which is not overlapped on the dielectric chip, is bent along the surface of the dielectric chip in order to improve the bandwidth of the antenna.

Taiwan patent number 513827 discloses an antenna apparatus that comprises a substrate, a chip antenna mounted on the substrate, and a ground pattern disposed on the substrate, at least a portion on the side of a power supply terminal of an antenna conductor in the chip antenna being overlapped with the ground pattern.

Taiwan published application number 200414604 discloses a chip antenna that includes a substrate, a plurality of helical conductors provided on the substrate, and a pair of terminals provided on the substrate. The chip antenna alone is capable of transmitting and receiving electromagnetic waves of a plurality of frequencies.

However, accompanying their miniaturizations, all of aforementioned chip antennas have a low radiating efficiency. Besides, the manufacturing processes of aforementioned chip antennas are not flexible so that it is difficult to make modifications of aforementioned chip antennas for different applications. Furthermore, the laminated ceramics of aforementioned antennas are prone to contraction and deformation during their sintering processes, which greatly decreases the yield rates thereof.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a small-sized ceramic chip antenna having a simple configuration so that the manufacturing processes thereof possess flexibility.

The ceramic chip antenna provided by the present invention is capable of improving radiating efficiency as well as being quickly and finely adjusted for applications in various different electronic products.

DETAILED DESCRIPTION OF THE INVENTION

Referring toFIGS. 1 through 3, a ceramic chip antenna in accordance with the present invention includes a substrate1and a conductor2formed on surfaces of the substrate1.

The substrate1is a thin plate of sintered ceramic material with a low dielectric loss and a high dielectric constant. The substrate1has a pair of concavities11,11′ cut from both longitudinal ends thereof.

The conductor2is a metallic conductor with a high Q factor as well as a good anti-oxidization property. The conductor2is formed on surfaces of the substrate1by means of mask etching or printing technology, with two conducting electrodes21,21′ disposed at the two concavities11,11′. The two conducting electrodes21,21′ are connected by a circuit portion22that is formed on surfaces of the substrate1in a meandered or helical manner. The circuit portion22can be further divided into a radiation zone23and a feeding terminal24.

The present invention is capable of remedying narrow bandwidth and low efficiency problems of conventional chip antennas, for the conductor2utilizes a high Q factor and good anti-oxidization metallic conductor, and is formed in a meandered and helical manner on surfaces of the substrate1that has a low dielectric loss and a high dielectric constant.

Altering the feeding terminal24, for example, varying the line space width and the number of turns of the feeding terminal24, can change the inductor volume thereof. Thus, the present invention can be quickly and finely adjusted for applications in various different electronic products.

Referring toFIG. 4, the present invention further comprises a protective membrane3enveloping the substrate1and the conductor2. The protective membrane3is a dielectric membrane whose dielectric property and figure and size can be adjusted in order to modify the chip antenna's resonant frequency.

Referring toFIG. 5, another embodiment of a ceramic chip antenna in accordance with the present invention is shown. The feeding terminal24comprises a plurality of exposed portions24aand a plurality of embedded portions24b. Each embedded portion24bpenetrates through the substrate1and connects two exposed portions24athat are formed on opposite surfaces of the substrate1.

The exposed portions24acan be either equally spaced or unequally spaced in order to modify the inductor volume of the feeding terminal24. In addition, altering the number of turns of the feeding terminal24can change the inductor volume of the chip antenna. Thus, the inductor volume of the chip antenna can be modified and thereby satisfying the demands of different electronic products.