Design of a Novel Microstrip Filter using Paired Fan-Shaped Capacitors for Harmonic Suppression

This paper proposes a novel microstrip filter using paired fan-shaped capacitor for harmonic suppression. By combining the fan-shaped capacitor with the parallel coupled resonator, the high-order harmonic parasitic passbands of the filter are suppressed. The frequency selection characteristics of the filter are well improved in both the simulated and measured S-parameter results. The proposed structure can be applied in many planar filter structures to increase out-of-band rejection.