A novel W-band WR 10 waveguide to microstrip line transition is designed, simulated in a 3D full-wave EM simulation software, fabricated, and evaluated by measurements. The main advantages of this transition are frequency-flat transmission, low reflection, and uncomplicated fabrication. Simulation shows a reflection coefficient of better than -23 dB from 75 to 90 GHz for one hollow waveguide to microstrip line transition. The port reflections increase for a fabricted prototype with two transitions and a connecting microstrip line to a level of about -14 dB. This is mainly caused by fabrication tolerances. The overall transmission of the dual transition prototype is found at a very satisfactory level of about -4.8 dB at 90 GHz for a connecting microstrip line with a length of 45 mm corresponding to an estimated loss of approximately 0.6 dB for a single transition.
2. Sun, J., F.-G. Liang, L.-H. Han, X.-Y. Sun, and Y.-Q. Zheng, Waveguide-to-microstrip antipodal finline transition at W band, 3rd Intern. Conf. on Instrumentation, Measurement, Computer, Communication and Control, 510-513, 2013.
3. Grabherr, W., W. G. B. Huder, and W. Menzel, "Microstrip to waveguide transition compatible with mm-wave integrated circuits," IEEE Trans. Microw. Theory Techn., Vol. 42, No. 9, 1842-1843, 1994.
4. Deguchi, Y., K. Sakakibara, N. Kikuma, and H. Hirayama, Millimeter-wave microstrip-towaveguide transition operating over broad frequency bandwidth, MTT-S International Microwave Symposium Digest, 2107-2110, 2005.
5. Brazalez, A. A., E. Rajo-Iglesias, J. L. Vazquez-Roy, A. Vosoogh, and P. S. Kildal, "Design and validation of microstrip gap waveguides and their transitions to rectangular waveguide, for millimeter-wave applications," IEEE Trans. Microw. Theory Techn., Vol. 63, No. 12, 4035-4050, 2015.
6. Seo, K., Planar microstrip-to-waveguide transition in millimeter-wave band, Advancement in Microstrip Antennas with Recent Applications, INTECH Open Access Publisher, 2013.
7. Seo, K., A. Nakatsu, K. Sakakibara, and N. Kikuma, Via-hole-less planar microstrip-to-waveguide transition in millimeter-wave band, China-Japan Joint Microw. Conf., 1-4, 2011.
8. Pozar, D. M., Microwave Engineering, 4th Ed., John Wiley & Sons, New Jersey, 2012.
9. Spinner GmbH, TD-00036, cross reference for hollow metallic waveguides, Munich, Germany, 2017, [Online], Available: http://www.spinner- group.com/images/download/technical documents/SPINNER TD00036.pdf.
10. Hamberger, G. F., S. Trummer, U. Siart, and T. F. Eibert, "A single layer dual linearly polarized microstrip patch antenna array for automotive applications in the 77GHz band," IEEE Intern. Symp. on Phased Array Systems and Techn., 1-4, 2016.
11. Spinner GmbH, TD-00077, anges for ordinary rectangular waveguides, Munich, Germany, 2017, [Online], Available: http://www.spinner- group.com/images/download/technical documents/ SPINNER TD00077.pdf.
12. Rogers, RO3000 series circuit materials, 2017, [Online], Available: www.rogerscorp.com/documents/722/acs/RO3000-Laminate-Data-Sheet-RO3003-RO3006-RO3010.pdf/.
13. CST Computer Simulation Technology, Microwave Studio, Darmstadt, Germany, 2017, [Online], Available: http//www.cst.com.
14. LPKF, Technische Daten: LPKF Protolaser S, Garbsen, Germany, 2017, [Online], Available: www.lpkf.de/produkte/rapid-pcb-prototyping/laserstrukturierung/laser-strukturierenleiterplatten-prototypen.