The band-pass filter with the ultrawide stopband and interference rejection level more than 100 dB

The authors propose miniature constructions of the stripline resonator performed on a double-layer suspended substrate and bandpass filters on its base. The filters have a wide stopband with high attenuation. The experimental bandpass filter of the fourth order with percentage bandwidth 5 % has the stopband on the level of -100 dB up to the frequency that 10 times exceeds the passband center frequency. It is shown that the miniature filters based on the proposed resonator could be effectively produced by LTCC technology.