A Generalized Dual-Frequency Transformer for Two Arbitrary Complex Frequency-Dependent Impedances

• Published in: IEEE microwave and wireless components letters Vol. 19; no. 12; pp. 792 - 794
• Main Authors: Wu, Yongle, Liu, Yuanan, Li, Shulan, Yu, Cuiping, Liu, Xin
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.12.2009; Institute of Electrical and Electronics Engineers
• Subjects: Applied sciences; Circuit properties; Complex frequency-dependent impedances; Computer simulation; Design engineering; Design methodology; Dual band; dual-frequency; Electric, optical and optoelectronic circuits; Electronic circuits; Electronic equipment and fabrication. Passive components, printed wiring boards, connectics; Electronics; Equations; Exact sciences and technology; Exact solutions; Frequency conversion; Impedance; Mathematical analysis; Mathematical models; Microstrip; Microwaves; Noise levels; Numerical simulation; Power dividers; Signal convertors; T-junction power divider (T-JPD); Transformers; Transmission line theory; Wavelength measurement; Electric transformer; Frequency dependence; transformers; dual-frequency; Power electronics; Closed form equation; Complex impedance; Power divider; Complex frequency-dependent impedances; dual-band; Frequency converter; Analytical method; T-junction power divider (T-JPD); Numerical simulation; Transmission line theory; Multiple frequency; T shape
• ISSN: 1531-1309; 1558-1764
• DOI: 10.1109/LMWC.2009.2034034

The purpose of this letter is to propose a dual-frequency transformer for two arbitrary complex frequency- dependent impedances (ACF-DIs) and present a generalized T-junction power divider (T-JPD) operating at dual-band with arbitrary power-dividing ratios based on the proposed transformer. By the rigorous analysis of transmission line theory, the closed-form design equations for this generalized transformer are obtained. Using the analytical design method, a kind of generalized T-JPD can be designed to operate at two different frequencies with different power-dividing ratios. Furthermore, numerical examples are simulated and a microstrip T-JPD operating at 1 and 2.4 GHz with different power-dividing ratios (1.5 and 2 dB, respectively) is fabricated. Good agreements between the simulated and measured results can be observed.