本論文研究如何使用阻抗匹配的方式，來達成小型化且寬頻的微帶線至基板合成波導轉接，分別討論四種高阻抗微帶線至基板合成波導的轉接結構以及五種低阻抗微帶線至基板合成波導的轉接結構。
關於四種微帶線至低阻抗基板合成波導的轉接結構，直接轉接的長度為0 mm，但是在X-band (8.2-12.4 GHz)中，其-20 dB反射係數頻寬只有17.98%。使用漸變式微帶線作為轉接結構，其-20 dB反射係數頻寬為38.69%，相當寬頻，幾乎涵蓋整個X-band (8.2-12.4 GHz)，但是轉接電路長度卻增加為4.22 mm。使用漸變式基板合成波導的結構做轉接，雖然轉接的電路長度可以縮短為3.3 mm，但是其-20 dB反射係數頻寬只有4.12%。在訊號線上使用開路殘段的轉接，其-20 dB反射係數頻寬為38.00%，相當寬頻，幾乎涵蓋整個X-band (8.2-12.4 GHz)，並且其轉接電路長度只有1.25 mm，相當小型化；在接地面上使用開路殘段的轉接，其-20 dB反射係數頻寬為31.99%，與使用漸變式微帶線與在訊號線上使用開路殘段的轉接相比，頻寬稍窄，另外，雖然其轉接電路長度稍微增加為1.6 mm，但是不會損耗訊號線上的電路面積。
關於五種微帶線至高阻抗基板合成波導轉接結構，直接轉接的長度為0 mm，但是在Ku-band (12.4-18 GHz)中，其-20 dB反射係數頻寬只有12.64%。使用漸變式微帶線作為轉接結構，其-20 dB反射係數頻寬只有13.97%，與直接轉接差異不大，並且轉接電路長度增加為2.855 mm。使用漸變式基板合成波導的轉接，雖然轉接的電路長度增加為3.3 mm，但是其-20 dB反射係數頻寬為35.22%，相當寬頻，幾乎涵蓋整個Ku-band (12.4-18 GHz)。在訊號線上使用開路殘段的轉接，其-20 dB反射係數頻寬為0%，無轉接效果，並且轉接電路長度增加為3.7 mm；在地面上使用開路殘段的轉接，其-20 dB反射係數頻寬為26.63%，與使用漸變式基板合成波導相比，雖然頻寬較窄，但是其轉接電路長度只有2.7 mm，並且不會損耗訊號線上的電路面積。移除基板合成波導之第一組貫孔的轉接，雖然其轉接電路長度進一步縮小為2 mm，但是其-20 dB反射係數頻寬也跟著縮小為23.45%。在訊號線上加上短路殘段的轉接，雖然轉接電路長度可以進一步縮小為1.8 mm，但是其-20 dB反射係數頻寬也進一步縮小為18.22%。
為了降低板材的損耗，高階的板材是必須的，而板材成本也會跟著提高，小型化的設計能夠直接降低板材的成本，因此，本論文探討了許多種減少電路面積之設計，以提升實務上的價值。

In this thesis, the concept of impedance matching is utilized to accomplish the compact and broadband microstrip line to substrate integrated waveguide transitions. Four high-impedance microstrip line to substrate integrated waveguide transitions and five low-impedance microstrip line to substrate integrated waveguide transitions are investigated.
Concerning the four microstrip line to low-impedance substrate integrated waveguide transitions, although the direct microstrip line to substrate integrated waveguide transition has a transition length of 0 mm, the -20 dB fractional bandwidth of the reflection coefficient in the X-band (8.2-12.4 GHz) is only 17.98%. The transition using the tapered microstrip line can has a -20 dB fractional bandwidth of 38.69%, almost covering the whole X-band (8.2-12.4 GHz), but the transition length is as large as 4.22 mm. Although the transition using the tapered substrate integrated waveguide can reduce the transition length to a value of 3.3 mm, its -20 dB fractional bandwidth is only 4.12%. The transition using the open-circuited stub on the signal line can both achieve a -20 dB fractional bandwidth of 38.00%, almost covering the whole X-band (8.2-12.4 GHz), and reduce the transition length to a value of 1.25 mm, which is very small. The transition using the open-circuited stub on the ground plane can achieve a -20 dB fractional bandwidth of 31.99%, which is somewhat smaller than the -20 dB fractional bandwidths of the transition using the tapered microstrip line and the transition using the open circuited stub on the signal line, but the transition would not occupy any area on the signal line even though the transition length is somewhat increased to a value of 1.6 mm.
Concerning the five microstrip line to high-impedance substrate integrated waveguide transitions, although the direct microstrip line to substrate integrated waveguide transition has a transition length of 0 mm, the -20 dB fractional bandwidth of the reflection coefficient in the Ku-band (12.4-18 GHz) is only 12.64%. The transition using the tapered microstrip line has a -20 dB fractional bandwidth of 13.97%, which is almost the same as that of the direct transition, and the transition length is increased to a value of 2.855 mm. Although the transition using the tapered substrate integrated waveguide would increase the transition length to a value of 3.3 mm, it has a large -20 dB fractional bandwidth of 35.22%, almost covering the whole Ku-band (12.4-18 GHz). The failed transition using the open-circuited stub on the signal line has a -20 dB fractional bandwidth of 0% and the transition length is increased to a value of 3.7 mm. The transition using the open circuited stub on the ground plane can achieve a -20 dB fractional bandwidth of 26.63%, which is somewhat smaller than the -20 dB fractional bandwidth of the transition using the tapered substrate integrated waveguide, but the transition length can be reduced to a value of 2.7 mm and the transition would not occupy any area on the signal line. Although the transition with the removal of first via of the substrate integrated waveguide can further reduce the transition length to a value of 2 mm, its -20 dB fractional bandwidth is also reduced to 23.45%. Although the transition using the short-circuited stub on the signal line can furthermore reduce the transition length to a value of 1.8 mm, its -20 dB fractional bandwidth is also reduced to 18.22%.
In order to eliminate the substrate loss, high-order substrate is required. However, the cost will increase alongside. Compact transition can directly reduce the area of the transition, which in turn reduce the cost. This thesis proposes various compact and broadband transitions, which may find applications in the industrial.

參考資料
[1] J. Rayas-Sanchez, and J. Jasso-Urzúa. “EM-Based Optimization of a Single Layer SIW with Microstrip Transitions using Linear Output Space Mapping,” 2009 IEEE MTT-S International Microwave Symposium Digest, pp.525-528, Jun 2009.
[2] Dominic Deslandes, “Design Equations for Tapered Microstrip-to-Substrate Integrated Waveguide Transitions,” 2010 IEEE MTT-S International Microwave Symposium, pp.704-707, May 2010.
[3] M. Abdolhamidi, A. Enayati, M. Shahabadi, and R. Faraji-Dana, “Wideband single-layer DC-decoupled substrate integrated waveguide (SIW)—to—Microstrip transition using an interdigital configuration”, 2007 Asia-Pacific Microwave Conference, pp. 1-4, Dec 2007.
[4] Z. Liu, and G.-B. Viao, “A New Transition for SIW and Microstrip Line” 2013 Asia-Pacific Microwave Conference Proceedings (APMC), pp. 948-950, Nov 2013.
[5] H. Nam, T.-S. Yun, K.-B. Kim, K.-C. Yoon, J.-C. Lee, “Ku-band transition between microstrip and substrate integrated waveguide (SIW)”, 2005 Asia-Pacific Microwave Conference Proceedings, pp. 1-4, Dec 2005.
[6] Z. Kordiboroujeni, and Jens Bornemann, “New Wideband Transition From Microstrip Line to Substrate Integrated Waveguide”, IEEE Transactions on Microwave Theory and Techniques, pp. 2983-2989, Nov 2014.
[7] E. Diaz Caballero, A. Belenguer Martinez, H. Esteban Gonzalez, O. Monerris Belda and V. Boria Esbert, “A Novel Transition from Microstrip to a Substrate Integrated Waveguide with Higher Characteristic Impedance”, 2013 IEEE MTT-S International Microwave Symposium Digest (MTT), Jun 2013.
[8] H. H. Kao, “Compact and Broadband Microstrip Line to Rectangular Waveguide or Substrated-integrated Waveguide Transitions”, master’s degree thesis.
[9] D. M. Pozar, Microwave engineering. 3rd ed. New York: John Wiley & Sons, 2005.