Papers by Muhammad Salman Anwar
Microwave and Optical Technology Letters, 2019
This paper presents the design of compact cross-coupled microstrip trisection bandpass filters ba... more This paper presents the design of compact cross-coupled microstrip trisection bandpass filters based on the hybrid structures of quarter-wavelength (λ/4) and half-wavelength (λ/2) resonators. The desired cross-couplings for transmission zeros (TZ) are realized by parallel coupled transmission line sections (Jinverter) or coupled via sections (K-inverter) of λ/4 resonators. The main line couplings on the other hand, are formed by mixed-coupled λ/4 and λ/2 resonators. In order to validate the proposed hybrid configurations, two X-band trisection filters with 6.5% and 6.2% fractional bandwidth (FBW) were designed, fabricated and measured. The first filter generates a TZ below the passband, while the second one produces a TZ above the passband. Minimum insertion loss of 1.7 dB and 1.5 dB were observed for the two trisection filters, respectively, while the hybrid configurations caused significant size reduction in the overall filter size. Moreover, the first spurious response for the proposed filter topologies was pushed to 3fo, resulting in a widestopband-fo is the passband center frequency. The measured and simulated S-parameters show good agreement, which proves the validity and accuracy of the proposed hybrid design methodology.
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Papers by Muhammad Salman Anwar