Compact Chebyshev-function low-pass filters with stepped-impedance hairpin unit

The objective of this paper is to study the stepped-impedance hairpin unit towards realizing three transmission zeros while applying this unit to design of multi order low-pass filters with widened and deepened upper-stopband. A synthesis method is then presented to design of two Chebyshev-function low-pass filters. Finally, two low-pass filters of 3rd - and 5th -order are designed and fabricated. Experimental results prove that the designed low-pass filters have achieved widened upper- stopband and sharpened roll-off shirt near cut-off frequencies.