| Abstrakt: |
This study proposes a design method for implementing a low-pass filter that suppresses harmonic components in an ultrawide bandwidth using a stepped impedance structure with a defected ground stripline structure. The proposed defected ground stripline structure can obtain an impedance ratio that is more than 60 times higher than those of other transmission lines and conventional defected ground structures, owing to the asymmetrical ground plane of the stripline, making it possible to design a stepped impedance filter with a wideband harmonic suppression band and a high harmonic suppression level. In addition, for an efficient filter design, the cross-sectional shape of the proposed defected ground stripline was analyzed by conformal mapping, and a design equation for calculating the characteristic impedance with high accuracy was derived, making it possible to design accurately and quickly without EM simulations. Using the proposed defected ground stripline structure with a high impedance ratio, a 9th-order Chebyshev filter (0.1 dB ripple) with a cutoff frequency (fc) of 1.1 GHz, providing a high harmonic suppression level of more than 40 dB, up to 36.4 fc, is implemented. [ABSTRACT FROM AUTHOR] |
