Design Of Passive Ultra-wideband Device Based On Microstrip-siot Transitions

Ultra wideband technology is a new technology of carrier free communication thattransmits data in nanosecond to microsecond pulse.With the rapid development of wireless communication, the demands for compactultra wideband RF ends are also increasing. Nowadays, these sub-systems usually workin the microwave bands, including filters and power dividers. This has prompted themicrowave designers continue to develop ultra wideband technologies. In this paper, westudied the related theory and technology. Then ultra wideband filter and wide-bandbalanced power divider based on the microstrip-slotline transitions are proposed. Themain research contents of this paper are as follows:First of all, we realize the filter’s ultra wideband characteristic based on themicrostrip-slotline transitions. On this basis, the selectivity of the filter is enhanced byan open annular stub terminated at the intersection. Passband and stop-bandcharacteristics are improved by the coupling between output part and input part.Secondly, SIR is coupled on the proposed UWB filter; the UWB filter with5.8GHzband-notched is realized. On the basis of that, an UWB power divider with narrowband-notched and wide stop-band is designed by SIR and microstrip-slot transitions.The UWB filter with a band-notch is simulated by full-wave simulation software andmeasured by vector network analyzer. The results show the correctness of the designmethods.Finally, in order to adapt to the requirements of the differential circuit, this paperproposed a simple and novel balanced wideband PD with enhanced CM suppression.Then three isolation resistors are used to increase the isolation of the proposed powerdivider, and the folding microsrip makes the the size of whole power divider remainscompact. The measured results show good performance and validity of the designmethod.