2-6 GHz氮化鎵功率放大器積體電路與模組之研究

Abstract

此論文分為三個主要部分，探討在2-6 GHz頻段應用於軍事及衛星設備的寬頻功率放大器及模組。 第一部分介紹了0.25微米氮化鎵高電子遷移率電晶體製程的寬頻放大器設計。該電路採用了最佳化的路徑匹配網路及電容性和電感性磁耦合共振腔實現寬頻匹配。量測結果顯示，初版設計的增益為18.3至23.3 dB，全頻段飽和功率超過34.7 dBm，功率附加效率超過29.8%。為了進一步提升性能，我們進行了優化的再設計，沿用了最佳化的路徑匹配網路及改良磁耦合共振腔達到匹配。量測結果之增益提升至19.5至25.4 dB，全頻段飽和功率超過35.3 dBm，功率附加效率則超過36.5%，顯示這些改進有效地優化了電路特性。而高瓦數的輸出功率使得散熱成為量測中的一大挑戰，故設計了銅塊加速散熱，已達到更好的量測結果。兩電路設計皆使用小於3平方毫米的面積，彰顯其高功率密度之競爭力。 第二個部分同為0.25微米氮化鎵高電子遷移率電晶體製程所設計之2-6 GHz頻段寬頻放大器，但此功率規格提升至十瓦。此電路採用改良式磁耦合共振腔及電容性及電感性之磁耦合共振腔來達到寬頻匹配。同第二章之設計，高瓦數之輸出功率使得散熱成為量測中重要的一環，故也加入了銅塊設計加速散熱，已達到更好的量測結果。此電路量測增益達13.8至21 dB，飽和功率於全頻段超過40.2 dBm，而功率附加效率則超過 21%。 第三部分延伸自第二部分的設計，為一平衡式放大器之設計。此平衡式放大器由帶狀線寬頻耦合器、共面波導與帶狀線之轉接設計及兩顆十瓦功率放大器組合而成，同樣採用銅塊散熱設計來優化量測結果。此電路量測增益達8.9 至 18 dB，飽和功率於全頻段超過40 dBm ，而功率附加效率則超過 20.5%。

This paper is divided into three main parts, dedicated to designing broadband power amplifiers and modules for military and satellite applications in 2-6 GHz. The first part introduces a broadband amplifier design using a 0.25-um GaN process. This design employs optimal matching network contour and capacitively and inductively magnetically coupled resonators for broadband matching. Measurement results indicate an initial gain of 18.3 to 23.3 dB, a saturated power exceeding 34.7 dBm, and a power added efficiency surpassing 29.8%. A re-design network is conducted to enhance performance by using an optimal matching network with a more compact layout for output matching and the extended magnetically coupled resonator (MCR) for interstage and input matching, achieving a gain of 19.5 to 25.4 dB, a saturated power over 35.3 dBm, and a power added efficiency exceeding 36.5%. The measurements are conducted with a copper design under the chip since the heat generated by the large output power may jeopardize the overall performance. These results show effective improvements in the re-design network. Additionally, both designs occupy less than 3 mm2 of chip size, demonstrating their competitive high power density. The second part also utilizes the 0.25um GaN process for a 2-6 GHz broadband amplifier, but with power specifications increased to 10 W. This design utilizes extended MCR technique and capacitively and inductively magnetically coupled resonators for broadband matching. Addressing previous challenges related to heat generated during measurements, a copper heat dissipation system has been incorporated into the design. This addition aims to enhance overall performance by effectively managing thermal issues and optimizing operational conditions for improved results. Measurement results for this proposed PA show a gain of 13.8 to 21 dB, a saturated power exceeding 40.2 dBm, and a power added efficiency exceeding 21% across the entire frequency band. The third part extends from the design of the second part to a balanced amplifier. This balanced amplifier is composed of two broadband quadrature couplers with stripline structures, CPWG-to-stripline transitions, and two 10 W PAs. Similarly, copper heat dissipation designs were employed to optimize measurement results. Measurement results for this proposed balanced amplifier demonstrate a Psat exceeding 40 dBm with a maximum of 41.8 dBm, a measured small signal gain of 8.9-18 dB, and a PAE exceeding 13.1% with a maximum of 20.5%.