Is to use alternating sections of very high and very low characteristic impedance lines for lowpass filters. Such filters are usually referred to as stepped-impedance, or hi-Z, low-Z filters, and are popular because they are easier to design and take up less space than a similar low-pass filter using stubs.
Published in Chapter:
Study of Some New Topologies and Associated Techniques Used for the Achievement of Planar Filters
Fouad Aytouna (Abdelmalek Essaadi University, Morocco), Mohamed Aghoutane (Abdelmalek Essaadi University, Morocco), Naima Amar Touhami (Abdelmalek Essaadi University, Morocco), and Mohamed Latrach (Microwave Group, ESEO, France)
Copyright: © 2017
|Pages: 39
DOI: 10.4018/978-1-5225-0773-4.ch007
Abstract
This chapter will treat firstly a summary of the filters synthesis by using Butterworth and chebyshev techniques. After that, a second part will be devoted to the design of planar filters using different techniques; this section will present some examples in bibliography. The aim of this part is to understand the different methods and steps followed to design planar filters, in the same time to discover and to define the different parameters which characterize a filter structure. Therefore, we have chosen some new research studies on low pass filers. The last part will present our contribution in designing planar filter. The first filter structure is a dual bandpass microstrip filter operating for DCS and Wimax applications, this section will introduce the different steps followed to achieve such filter. The second circuit is a novel design low cost microstrip lowpass filter with a cutoff frequency of 2.3 GHz. At the end, we will present a transformation of the microstrip filter to a CPW lowpass filter making it easy for integration with passive and active microwave components.