Özet:
In this paper, a novel dual wideband microstrip bandpass
filter is proposed. The designed filter is constructed by two
different stub loaded resonators located at the upper and
bottom sides of the coupling line. The coupling transmission
line is also connected to input and output (IO) ports.
The upper resonator creates a wide passband, whereas the
bottom resonator is used to create two transmission zeros
in the passband. Thus, a wide passband can be divided into
dual wide passbands. The bottom resonator is also utilized
to improve the insertion and return losses in the passband.
The designed filter is fabricated and tested in a very good
agreement with the simulated results. The measured fractional
bandwidths (FBWs) of the passbands are 44.6% and
24.2% at the center frequencies of 3.4 GHz and 5.51 GHz,
respectively. The measured insertion losses in the passbands
are 0.51 dB and 1.13 dB.