Windowing UWB microwave, mm-wave multi-port S-parameter measurements using open-ended excess electrical length

Abstract

Multi-port measurements are a big challenge in circuits' verification, especially when the frequency increases. This study presents a new technique for measuring S-parameters of multi-port ultra-wideband (UWB) microwave and mm-wave circuits. The concepts are based on direct or indirect applying modulated UWB impulse radio in desired bandwidth to the one port of the modified multi-port circuit and gathering the reflected signal in the same port and the output signal in the second port in time domain, and the other ports are left opened with a special designed added electrical length. Then by applying intelligent windowing in time domain to the gathering data, and using fast Fourier transform, the desired S-parameters are extracted. Validation of this technique is verified by design and fabrication of a three-port UWB Wilkinson power divider in 22–30 GHz. The simulation and measurement results of the reflection and transmission S-parameters by using this new technique are very close to those are extracted with the conventional vector network analysers S-parameters measurements and show the ability and the accuracy of this technique.

Keywords

• ultra wideband technology
• S-parameters
• microwave circuits
• millimetre wave circuits
• time-domain analysis
• fast Fourier transforms
• power dividers
• electromagnetic wave transmission
• electromagnetic wave reflection
• windowing UWB microwave multiport S-parameter measurement
• mm-wave multiport S-parameter measurements
• open-ended excess electrical length
• multiport measurements
• circuit verification
• multiport ultrawideband microwave circuits
• multiport ultrawideband mm-wave circuits
• UWB impulse radio
• time domain
• fast Fourier transform
• three-port UWB Wilkinson power divider
• transmission S-parameter
• reflection S-parameter
• vector network analysers
• frequency 22 GHz to 30 GHz