近年推出的各式行動裝置平台，像是平板電腦、家用小型基地台、智慧型手機，和筆記型電腦等，皆須整合多種無線通訊協定，而各種平台皆有特定的天線需求。對於筆記型電腦而言，已有多天線應用的需求。在多天線系統中，如何維持天線間的隔離度便是一大重要的研究課題。
本論文第一部份提出一種應用於筆電轉軸槽孔上的解耦合方法，藉由電流相位相消的原理，將天線放在筆電轉軸槽孔上，並將轉軸槽孔的長度設計在天線操作頻率之波長的整數倍，可讓天線的傳導電流流過轉軸到達另一支天線時正好達到相位相反而相消，提升兩支天線間的隔離度，兩支天線同時可在極小於操作頻率波長的距離內，維持天線原有的傳輸性能。在此部分，吾人對轉軸槽孔與天線頻率波長的關係進行探討與分析，同時對於此方法的理論以及可應用的頻率進行參數分析，並針對轉軸槽孔在非天線頻率之波長的整數倍時，提出幾種調整的方法。
第二部份是將此解耦合方法應用於不同款式的雙頻天線上，檢視此方法是否仍具有解耦合的效果。首先吾人設計一款原創的WLAN雙頻IFA天線，並將其應用於此解耦合方法中。天線在低頻的隔離度表現良好，與單頻IFA天線的隔離度表現相似，於高頻的隔離度表現尚佳，在部分頻率具解耦合效果，部分頻率則可維持一定的隔離度。同時可藉由調整天線間距，將隔離度進一步地提升。接著嘗試將此解耦合方法應用於另外四款不同型式且已知的雙頻天線上，測試其解耦合效果。對於傳導電流沿著板邊流動的天線型式，其低頻隔離度可被大幅度地改善，使相鄰天線能在極小於波長的距離內，仍能保持其傳輸性能。

Modern mobile devices, such as tablets, access points, smart phones and notebooks, need to incorporate a variety of communication protocols. Different platforms may require dissimilar antenna characteristics. For notebooks, support for MIMO operation has already been a must. Mobile devices therefore need to install multiple antennas with good isolation performance.
In the first part of this study, a decoupling technique, which utilizes the notebook hinge region, has been developed. We found that by setting the hinge slot length as multiple of wavelengths, a decoupling null can be created. This is due to cancellation of conduction emission currents around the hinge slot. The isolation and the performance of the antennas can be improved with this technique. As a result, the distance between two types antennas can be extremely reduced and the radiation performance is not perturbed.
In the second part of this study, different antenna types have been tested with this decoupling technique to exam the applicability of this technique. At first, a dual-band inverted-F antenna has been designed. In general, good isolation can be achieved with the 2.4 GHz band, while some tuning in antenna spacing or displacement may be needed to achieve decoupling in the 5 GHz band. We also applied this technique to the existing designs. For antennas that utilize the ground edge for radiation, the proposed technique can improve antenna isolation significantly and the two antennas can be place in a close distance.

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