Abstract
A direct synthesis and design approach to lowpass filter (LPF) with ultra-wide stopband is proposed. The LPF consists of multiple radial stubs and capacitively loaded stubs, all connected with high impedance transmission lines in cascade. The capacitively loaded stubs with long electrical lengths not only produce transmission zeros (TZs) close to the band edge to sharpen the roll-off, but also produce TZs in the far stopband. The radial stubs, which can be approximated by series LCs and are spurious-free in a wide frequency range, are used to generate extra controllable TZs in the far stopband. The layout of LPF can be accurately modelled by a mixed lumped/distributed (MLD) equivalent circuit, which can be systematically converted from a generalized Chebyshev lowpass prototype. To demonstrate the proposed design approach, a 17-degree lowpass filter with cut-off frequency ƒc of 2 GHz and approximately 40 dB rejection stopband up to 9 fc is presented.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.