A miniaturized interdigital hairpin microstrip bandpass filter design

In this paper, we have proposed a four-pole elliptic function band-pass filter, designed using compact miniaturized microstrip interdigital hairpin resonator. Miniaturization of hairpin resonator is realized by using an interdigital structure having parallel coupled lines. We have used the full-wave simulator IE3D to design the interdigital hairpin resonator. We chose RO4003C substrate for our design as it has many advantages in high frequency applications. This filter occupies a chip area of 20.2 * 28.2 mm², with a thickness of 1.5 mm and has a center frequency at 2.4 GHz with a 3dB bandwidth of 220 MHz and its upper cutoff and lower cutoff frequencies are respectively 2.53 GHz and 2.31 GHz.