Implementation of a broadband Ruthroff-type transmission line transformer balun with a 1:2 step-up impedance transformation ratio is presented in this letter. The proposed Transmission Line Transformer (TLT) balun was investigated with broadside-coupled lines using three stacked microstrip lines. The proposed balun was formed by cascading one section of modified Ruthroff-type 2:1 unbalanced-to-unbalanced TLT with one section of Ruthroff-type 1:4 TLT balun in series. The achieved fractional bandwidth of the balun is 192.17% over the frequency range from 1.2 to 6.6 GHz, which covers the IEEE 802.11 a/b/g WLAN, WiMAX applications. The measured amplitude and phase imbalances are less than 1 dB and less than 4.51˚, respectively at this frequency range.
Mohamed Toufik Benhabiles,
Mohamed Lahdi Riabi,
"A CMOS Compatible Broadband Ruthroff 1:2 TLT Balun Using Broadside-Coupled Lines and Stacked Microstrip Lines," Progress In Electromagnetics Research Letters,
Vol. 103, 1-6, 2022. doi:10.2528/PIERL22010402
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