Design of a compact microstrip low‐pass filter using defected ground structure

Abstract

A novel compact microstrip low‐pass filter (LPF) is proposed in this article. The proposed LPF is composed of semicircle‐defected ground structures (S‐DGS) and semicircle stepped‐impedance shunt stubs (S‐SISS). An equivalent lumped L‐C circuit model is also presented. With the S‐DGS and S‐SISS, better band‐stop performance and much smaller size can be obtained. Finally, theoretical and simulated results are presented, which are in good agreement with the measured results. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 3157–3160, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23938

Compact Microstrip Lowpass Filter With Ultra-Wide Stopband Performance Using Radial Stub Loaded Resonators

“…Thus, techniques to achieve both size reduction and performance enhancement have been continually studied. Commonly, there are typical two methods to design a lowpass filter with compact size and wide stopband [3][4][5][6][7][8][9][10].…”

“…The second method is to design a lowpass filter by using modified stepped impedance hairpin resonators [7][8][9][10][11]. Using a stepped impedance hairpin resonator with radial stubs, Wei et al proposed a lowpass filter with 7th harmonic suppression performance [7].…”

“…In addition, using defected ground structure is also a popular and useful way. A lowpass filter composed of semicircle defected ground structures and semicircle stepped-impedance shunt stubs is proposed in [10,11], but the circuit complexity and circuit size should be reduced.…”

Design of compact low‐pass filter with large reject band using open circuit stubs and two‐cascaded DGS quasitriangular resonators

“…Recently, there has been an increasing interest in microwave circuits design especially microstrip filter using defected ground structure (DGS). Nowadays, many researchers focus on this type of structure because it offers various advantages such as well applied to RF/microwave circuits to reduce the size [1–5], improve the performances [6–9], and easily performed to extract the equivalent circuit [1–4].…”

Compact miniaturized stepped impedance low‐pass filter with sharp cutoff characteristic

“…Recently, defected ground structure (DGS) [1][2][3] and microstrip stepped impedance resonator (SIR) [4 -6] are proposed for designing LPFs. To fabricate a LPF with steep rejection property, many DGSs and SIRs are needed [5,6].…”