使用單一二極體開關之五頻及七頻的可調頻手機天線

Abstract

本論文中，我們提出一種對於頻率可調手機天線的設計，以應用於WWAN與LTE頻段。天線是利用一迴路天線加上一PIN二極體之開關電路完成設計，藉由開關的控制來達成低頻的頻率可調，並且在低頻頻率切換之時，能夠繼續保有高頻頻段的特性，因此，此一天線可達到更多頻段的需求。在這樣的概念下，設計出兩個五頻可調頻天線以及一個七頻可調頻天線。 第一個天線主要用於切換GSM850/GSM900，在此切換之下，高頻能夠保持在GSM1800/GSM1900/UMTS2100這三個頻段，然後達成一五頻可調頻天線的設計。因應現在市場上的需要，天線底下可能需要一個完整性的接地面，以供於更多的電路面積被使用，因此再度設計一個天線應用於切換GSM850/GSM900，在此切換之下，高頻也能夠保有上述三個頻段，達成一接地面完整之五頻可調頻天線的設計。隨著LTE的發展，手機天線也要在往更低頻以及更多頻段發展，第三個天線即是用於切換LTE700、GSM850/GSM850、GSM900，在此切換下，高頻能夠保持在GSM1800/GSM1900/UMTS2100/WLAN2.4G這四個頻段，達成一七頻可調頻天線的設計。

In this thesis, a frequency reconfigurable antenna design for WWAN-band and LTE-band mobile phones is developed. This structure utilizes a loop antenna and the switching circuit of PIN diode. Through the operation of switch, three different loop lengths are switched so that the lower band is reconfigurable, and the higher band maintains its performance. As a result, this antenna can achieve much more bands. In this concept, we design two frequency reconfigurable antennas for penta-band mobile phones and a frequency reconfigurable antenna for seven-band mobile phones. The first proposed antenna has the capability of switching the lower band between the GSM850 and GSM900 frequency ranges with only a minor impact on the upper band. The upper band covers the frequency ranges of the GSM1800, DCS1900 and UMTS2100 communication standards. With the need of market, a complete ground is needed under the antenna to provide more area to lay out circuits. The second proposed antenna with the complete ground also has the capability of switching the lower band between the GSM850 and GSM900 frequency ranges and the upper band maintains GSM1800/GSM1900/UMTS2100. As mentioned above, we achieve two frequency reconfigurable antennas for penta-band mobile phones . With the development of LTE, The third proposed antenna has the capability of switching the lower band between the LTE700/GSM850 and GSM850/GSM900 frequency ranges. The upper band covers the frequency ranges of the GSM1800, DCS1900, UMTS2100 and WLAN2.4G. Consequently, we achieve a frequency reconfigurable antenna for seven-band mobile phones.