Optimization and validation of W-band waveguide-to-microstrip longitudinal probe transition

• Main Author: Wei, Zhi Cheng.
• Other Authors: Leong Yoke Choy
• Format: Final Year Project
• Language: English
• Published: 2009
• Subjects: DRNTU::Engineering::Electrical and electronic engineering::Antennas, wave guides, microwaves, radar, radio
• Online Access: http://hdl.handle.net/10356/17152
• Institution: Nanyang Technological University

A broadband waveguide-to-microstrip transition model is designed and optimized with the aid of electromagnetic CAD tools. The transition is realized by mounting a microstrip in longitudinal orientation onto the broadside of a WR-10 waveguide. The performance of the transition model exhibits return loss (S11) less than -20db and throughput (S21) more than -0.45dB over the entire W-band from 75GHz to 110GHz. For the ease of fabrication and experiment validation, a scaled-up model with a scale factor of 12.5 is designed and fabricated. Measurement is done by using a scaled-down bandwidth from 6GHz to 8.8GHz. Return loss less than -19db and throughput more than -1dB are measured. The results agree well with the simulation results. A waveguide-to-microstrip power divider is also designed based on previous transition model at software stage. The power divider adds another microstrip on to the waveguide parallel to previous microstrip. The power divider has a return loss no more than -9dB. The throughput at each output port is around -3dB.