Design Of Ultra-Wideband And Tri-band Power Divider

With the development of the wireless communication, microwave circuit isincreasingly used in wireless communication systems. Microwave power divider is avery important part of the microwave circuit. Studying of the UWB (ultra-wideband)power divider and multiple frequency power dividers are hot-spot for scientific researchpersonnel for the past few years. The design methods of UWB power divider, UWBpower divider with band-notched, UWB power divider with band-notched and widestop-band, UWB power divider with tunable notch and tri-band power divider areproposed.Firstly, the bandwidth of every frequency is broadened by the the interdigitalcoupled-lines when two frequencies of two-section Wilkinson power divider aredetermined. The UWB power divider is simulated by full-wave simulation software andmeasured by vector network analyzer. The results show the correctness of the designmethods.Secondly, SIR is coupled on the proposed UWB power divider, the UWB powerdivider with5.8GHz band-notched is realized. On the basis of that, an UWB powerdivider with narrow band-notched and wide stop-band is designed by SIR and dumbbellDGS (Defected ground structure). The UWB power divider with tunable notch isproposed by variable capacitance diode. The length change of the SIR transmission lineis controlled by the external voltage change of variable capacitance diode. Thesimulation and measurement results of these power dividers show the rationality of thedesign methods.Finally, for adapting the multi-band demand, the proposed tri-band power divideruses a triple-mode resonator which comprises a half wavelength resonator, a short stuband an open stub. Its bandwidth is expanded by the structure of broadband coupled-lines.Meanwhile, the size is reduced by folding transmission lines. This tri-band powerdivider is fabricated and measured. The measured results show good performance andvalidity of the design method.