New compact bandpass filter design using nonuniform transmission lines

Summary form only given. A novel compact bandpass filter using nonuniform transmission lines is discussed. In this filter, the central frequency is adjusted by varying the slope of a linear taper. Starting with a null slope, at f=880 MHz, variation of the slope from -10% to +10% allows one to modify the frequency from 600 MHz to 1.1 GHz, that is, -20% to +20%. The bandwidth of the filter is adjusted by modifying the width of the line at the entrance: the bandwidth can be adjusted from 5% to 40% by varying the width from 30 to 240 mils. This filter has been designed and tested on microstrip using Touchstone and MDS simulator. Experimental measurements show excellent agreement with simulation.<
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