Design of the Compensated Marchand Baluns and Its Applications in Millimeter-Wave Frequency Doublers

本論文為全新的補償式馬遜平衡不平衡轉換器之設計及其毫米波主動二倍頻器之應用。此平衡不平衡轉換器有效的改善當耦合器在奇模與偶模相位速率不相等時所造成不完美平衡轉換的現象。在本文中此平衡不平衡轉換器經由分析，並提出設計方法和流程。藉由全波模擬萃取出耦合器的相關參數，就可找到適當的補償線設計參數，以消除在平衡端的共模訊號來達到高平衡不平衡轉換。 將此平衡不平衡轉換器應用於毫米波二倍頻器。首先呈現一個K頻段二倍頻器，以台積電0.18微米金氧半場效電晶體製程來實現。此二倍頻器為單平衡式的架構並採用補償式馬遜平衡不平衡轉換器，經由適當的設計可達到轉換增益-10.2到-13.2 dB和3-dB比例頻寬 81%並且基頻諧波抑制高於33 dB。此二倍頻器驗證了補償式馬遜平衡不平衡轉換器之效果。接著呈現兩個D頻段二倍頻器，均以台積電65奈米金氧半場效電晶體製程實現。這兩個二倍頻器使用不同的設計方法。第一個電路重在於頻寬的設計，以達到轉換增益-9.7到 -12.3 dB和輸出頻率75到150 GHz。第二個在權衡轉換增益和比例頻寬中，設計匹配網路在電路的輸入端，以達到轉換增益-7.9到-11.3 dB和輸出頻率95到150 GHz。因為沒有輸入匹配網路，第一個電路的轉換增益較小，但頻寬較寬。就作者所知，這是在此頻段最寬頻的二倍頻器。This thesis consists of the design of the novel compensated Marchand balun and its applications in millimeter-wave frequency doublers. Using this compensated method, we can reduce the imperfect balance performance due to the unequal odd- and even-mode phase velocities of the coupled lines. A compensation line is used in the compensated Marchand balun to improve balanced performance. The design flow and method are presented in detail. Once the parameters of coupled lines are extracted by full-wave simulations, the physical dimensions of the compensation line can be obtained to remove common-mode signals at balanced ports. Three single-balanced doublers using the compensated Marchand baluns are presented. A 15-36 GHz doubler is realized by TSMC 0.18-μm CMOS technology. This doubler with the compensated Marchand balun achieves the conversion gain of -10.2 ~ -13.2 dB with the 3-dB bandwidth of 81% and the fundamental rejection of 33 dB. This doubler indeed verifies the compensated techniques. Two D-band doublers are implemented in TSMC 65-nm CMOS technology. One doubler (Doubler A) without input matching aims for the widest bandwidth performance and achieves the conversion gain of -9.7 ~ -12.3 dB over output frequency of 75-150 GHz. The other doubler (Doubler B) with input matching aims at high-conversion-gain/wide-bandwidth design and achieves the conversion gain of -7.9 ~ -11.3 dB over output frequency of 95-150 GHz. Due to the input matching, the conversion gain of the doubler A is lower than that of the doubler B, but the bandwidth of the doubler A is wider. To the author’s knowledge, the bandwidth of the doubler A is the widest in this frequency regime