| Summary: | 碩士 === 國立臺灣科技大學 === 電機工程系 === 96 === This thesis is to study three miniaturized antenna categories to achieve the various requirements consisted of compact, efficient, low cost and easy fabrication for mobile phone applications. These antenna designs include a miniature planar inverted-F antenna (PIFA), a compact multi-band antenna and three spiral FM antennas with their matching circuits for operating in different specific communication and multimedia bands. Besides, the liquid crystal polymer (LCP) is efficiently applied to manufacture process for both the proposed FM antennas and PIFA so that the antenna components can be easily protected and attached on circuit devices.
Owing to the space limitation of design receiving antenna for mobile phone, the traditional planar antennas required with additional empty space were not suitable to integrate in the circuit devices. Also, the general PIFAs with large antenna fabrication size are undesirable for commercial applications. Thus, a new miniaturized PIFA used in ISM band of 2.4GHz is presented to reduce the antenna occupied space and can be achieved a good radiation performance.
In the other hand, the miniaturization purpose of FM antenna is a very important challenge for antenna engineers since the FM broadcast system has attracted a lot of applications in recent years. In this thesis we investigate three miniature spiral FM antennas with their matching circuits to enhance the antenna radiation performance for utilizing in FM band. Also, a high efficiency low noise amplifier (LNA) can be designed to help proposed FM antennas to improve the receiving signal quality at some specific FM frequencies.
Finally, in order to meet the requirements for both of multimedia and mobile communication, a multi-band antenna is studied for applying with GSM, Bluetooth, WiFi, WiMAX and commercial UWB bands. This compact antenna mainly uses multi-branched monopole antenna and loop antenna to achieve the purpose with multi-band application. Moreover, the antenna resonant frequencies and radiation performance can be increased by using short pin design so that the antenna dimensions can be reduced more flexibly. Therefore, this multi-band antenna size has much smaller than other designs, such as IFAs, PIFAs and other microstrip antennas for mobile phone applications. Furthermore, the proposed antenna can be easily printed with general PCB to reduce the complexity of antenna fabrication.
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