Unlimited Power Division Ratio of Microstrip Balanced-to-Unbalanced Gysel-Type Arbitrary Power Divider

Zihui Zhu, Zhongbao Wang, Ye Fu, Shaojun Fang, Hongmei Liu, Zhi Ning Chen
2020 Electronics  
A microstrip balanced-to-unbalanced (BTU) Gysel-type arbitrary power divider without the high-impedance transmission-line (TL) section is proposed to eliminate the power division ratio (PDR) limit of the conventional microstrip BTU power dividers. The proposed circuit includes five moderate-impedance TLs having the same characteristic impedance in addition to a grounded resistor. The arbitrary PDR is easily obtained by varying the electrical length of the TLs without changing the characteristic
more » ... impedances, especially the large PDR, which is difficult to achieve by means of conventional BTU power dividers. When the PDR is ∞, the proposed circuit becomes a balun. The closed-form design equations are derived and discussed. To verify the proposed circuit, three prototypes I, II, and III are designed and fabricated for PDRs of 10 dB, 20 dB, and ∞ dB, respectively. The measured PDRs are in good agreement with the simulations. The measured isolation between the output ports is higher than 31 dB for prototypes I and II. The measured insertion loss of the balun prototype is 0.194 dB. Furthermore, the common-mode suppression of greater than 32 dB and the return loss of higher than 22 dB are obtained for various PDRs.
doi:10.3390/electronics9071124 fatcat:rbi3dpqfo5akbgh5tssfk3usli