Abstract:
Recently, there has been increased interest for PBG/EBG structures in microwave and
antenna community. These structures consist of a periodic perturbation in a certain
medium so that they can exhibit frequency selective characteristics in certain frequency
bands and/or in certain directions in space and these structures can be implemented in
many ways[l,2]. Due to its frequency selective characteristics, EBG structures
naturally find applications in microwave filters. There are a number of publications
dealing about use of EaGs in microwave filters but majority of them deal with
microstrip implementation [1]. In recent times, CPW technology has found to be
favorable for the development of periodically loaded transmission line since only
single metallisation level is required for signal and ground thus easing device
grounding and reducing line to line coupling. CPW structures are also advantageous
for loading with shunt capacitances [2,3]. In this paper, we investigate various
periodically loaded defective ground plane structures for the design and the
optimization of lowpass and bandpass filters in uniplanar CPW configurations.
Simulated results for different filter geometries are presented.
