Miniaturized UWB BPF with a notch band at 5.8 GHz using cascaded structure of highpass and lowpass filter

Abstract

The objective of this paper is to reduce the size of UWB filter with a notch without any via or DGS to make fabrication easier. The proposed filter is designed by cascading high pass and low pass filter. High pass structure is created by a planar Interdigital structure and low pass is created by a Hairpin line, which make the overall size of the filter much miniaturized. The frequency response of the filter has pass band frequency between 3.1 and 10.6 GHz with wide stop band. There is a notch in pass band at 5.8 GHz with attenuation around 16 dB to avoid interference from the WLAN. The overall size of the filter is 3.36 × 4.132 mm2 which is much smaller than many previously reported structure of filters.