In this paper, coplanar waveguide (CPW) bandpass filters based on capacitively coupled resonators and periodic perturbation in slot width are proposed. Due to periodicity, the structure behaves as a reflector in a certain frequency band and harmonic suppression is achieved. Slot-width modulation has been implemented through the approximation of the ground planes to the conductor strip at periodic locations. The equivalent capacitance of the line is thus enhanced, with the result of a significant slow-wave effect. In comparison to a conventional design, the fabricated prototype is 1.4 times smaller and exhibits significant rejection of frequency parasitics.
- Coplanar waveguide (CPW)
- Electromagnetic bandgap (EBG)
- Microwave filter