Browsing by Author "Chin, Kuo-Sheng"

Now showing 1 - 2 of 2

Microstrip open-loop resonator with multispurious suppression
(2007-08-01)
Chin, Kuo-Sheng
;
Chiang, Yi-Chyun
;
Kuo, Jen-Tsai
;
電信工程研究所
;
Institute of Communications Engineering
A compact open-loop resonator with multispurious suppression is proposed. When excited symmetrically, the resonator shows two tunable transmission zeros. By adjusting the open-end gap capacitance, one of the zeros is placed near the passband and the other is tuned to collocate with the leading two degenerated higher order resonances, so that the circuit has a sharp transition as well as a wide upper stopband. The experimental circuit shows the first spurious peak occurs at four times the passband frequency (4f(o)), and the measurement shows good agreement with the theoretic prediction.
New synthesis of parallel-coupled line bandpass filters with Chebyshev responses
(2008-07-01)
Chin, Kuo-Sheng
;
Chiou, Yi-Chyun
;
Kuo, Jen-Tsai
;
電信工程研究所
;
Institute of Communications Engineering
Parallel-coupled line filters with Chebysbev passbands are synthesized based on the insertion-loss functions derived by converting the composite ABCD matrices of all coupled stages. With the synthesis, both the electromagnetic simulation and measurement results have accurate in-band response and bandwidth. Simultaneous equations for Chebyshev filters of order N <= 9 are derived for determining geometric parameters of the coupled stages. The tradeoff between circuit bandwidth and ripple level is discussed. In experiments, three planar or quasi-planar structures, including the coupled-line with aperture in the ground plane, the three-line microstrip, and the broadside-coupled lines, are employed to realize the end stages for implementing the high coupling levels. Experimental filters of order up to nine with fractional bandwidth of 30% or 40% are fabricated and measured. The results show good agreement with predictions by the theory and simulation.