隨著近年來資訊科技的進步，通訊技術的需求愈顯重要。採用高頻的微波通訊可以紓解擁擠的低頻段區域，另外寬頻的電路設計，亦可容納較多的應用。在本論文中，共有四個設計在K/Ka頻的寬頻平衡式放大器，兩個是運用標準CMOS製程製作而兩個是利用Above-IC技術所製作的藍基偶合器所設計。
運用標準CMOS製程所製作的平衡式放大器是針對K/Ka頻所設計。其中一個是針對K頻，設計頻率在17GHz~28GHz；另外一個是橫跨K/Ka頻，設計頻率是在26.6GHz~33.6GHz。模擬結果顯示，第一個電路在17.5GHz~28GHz有24~25dB的增益，而第二個電路在26.6GHz~33.6GHz有17dB的增益。在這兩個平衡式放大器電路中所使用的摺疊式藍基偶合器可以有效的縮短偶合器的直線長度。量測結果亦附在其後。
在現今的積體電路技術中，由於被動元件所造成的面積消耗，往往導致IC製作的費用的增加。在Above-IC技術中，被動元件是製作在主動元件的上層，藉由良好的佈局，可以將面積做最好的運用，進而節省製作的費用。在本篇論文的最後一章，運用Above-IC技術所製作的藍基偶合器在20GHz~40GHz呈現相當好的-4dB的耦合參數。
上述利用Above-IC技術所製作的藍基偶合器，由於有相當好的耦合參數，故可以用來設計平衡式放大器。本篇論文最後提出兩個平衡式放大器，是利用上述的藍基偶合器所設計及改良後的主動電路所構成。模擬結果顯示其中一個在19.1GHz~27.1GHz有20dB的增益，而另一個在24.2GHz~32.2GHz有18.5dB的增益。

With the growth of the IT industry, the technologies of communication arouse more and more attention in these years. Microwave wireless communication using high frequency can relax the crowded low frequency band. Besides, wide bandwidth can accommodate more applications. In this work, four wide-band balanced amplifiers designed at K/Ka Band were presented. Two balanced amplifiers used standard CMOS technology and two balanced amplifiers used Above-IC technology.
Two amplifiers were fabricated by standard CMOS technology. One focus on K band, which is 17GHz~28GHz.The other one focus on 26.6GHz to 33.6GHz, which is across K and Ka band. The simulation results show good performance on gain and bandwidth. For the former one, simulation results show the gain of 24~25dB from 17.5GHz to 28GHz. For the latter one, simulation results show the gain of 17dB from 26.6GHz to 33.6GHz.The folded Lange couplers used in these two balanced amplifiers can effectively reduce the length of ordinary Lange coupler. The measurement results were also included.
In modern IC technology, large part of area could be consumed by passive devices, leading to huge cost. In Above-IC technology, the passive devices are made on the upper layer of the active devices. In the latter part of this work, Lange couplers fabricated by Above-IC technology were presented. From measurement results, the Lange coupler designed at 20~40GHz shows good coupling factor of -4dB.
By using measurement data of the Lange couplers by Above-IC technology, two balanced amplifiers with improved structure designed at K/Ka band were presented. One shows the gain of 20dB from 19.1GHz to 27.1GHz. And the other one shows the gain of 18.5dB from 24.2GHz to 32.2GHz.

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