A compact UWB bandpass filter with a wide upper stopband using multiple transmission zeros

In this article, a compact bandpass filter is proposed for lower band (3.1–4.9 GHz) of ultra-wideband applications. The filter is mainly composed of a pseudo-interdigital wideband bandpass filter (PI-WBF) and a multiple transmission-zeros structure (MTZS), being a bandstop filter. By using the MTZS, multiple transmission zeros can be located in the upper stopband of the PI-WBF. The design procedure is discussed in detail. The designed filter was fabricated and measured. Measured results also have a good agreement with the simulated results. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 380–382, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23103