6TH International Congress on Technology - Engineering - Kuala Lumpur3 - Malaysia (2018-07-19)

Design And Implementation Of Transmission-line Transformers

New formulations based on the Z-domain are demonstrated to cascade transmission line sections and study quadruple-band transformers. Transformer configuration consists of six-section serial lines. The design methods employ prototypes of transfer function, parametric modeling techniques, and optimization methods; Quadruple-band uncorrelated frequencies of transfer function at the normalizing frequency (?) are studied. This transformer was designed on a PCB FR4 substrate featuring a permittivity ?r = 4.4, a loss tangent tan? = 0.0245, and a thickness of h = 1.6 mm. The results of simulation and measurement show that load impedance can be matched at four uncorrlelated frequencies. The values of characteristic impedances of transmission lines synthesizing the transformers are adjusted according to the autoregressive (AR) process by optimization algorithms. The proposed methods are verified with experimental results for a impedance transformer. The experimental results are in good agreement with theoretical values.
Lin-Chuan Tsai, Wen-Cheng Lai Lai