Design of UWB lowpass filter using a novel defected ground structure

In this study, firstly, a novel U‐shaped defected ground structure(UDGS) cell is proposed to hold both wide band gap and excellent slow‐wave characteristic. The design, simulation, and fabrication of compact ultra wideband(UWB) low pass filters (LPFs) using two UDGSs and a compensated microstrip line are reported. No open stubs, high impedance lines, and tee‐/cross‐junction are required, which makes the proposed LPFs smaller in size and suitable for high power application. Investigations on the slow‐wave effects and scattering/radiation levels for a microstrip with the UDGS are also included. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1805–1807, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21772