Title: A Fully Tunable Two-Pole Bandpass Filter
Authors: Chi, Pei-Ling
Yang, Tao
Tsai, Tsung-Ying
Undergraduate Honors Program of Electrical Engineering and Computer Science
Keywords: Bandwidth-control network;constant absolute-bandwidth;fully tunable;source-load coupling
Issue Date: 1-May-2015
Abstract: In this letter, a two-pole tunable combline filter that allows for operational agility of the center frequency, passband bandwidth, and locations of upper and lower transmission zeros is proposed. To increase the tunable range of constant absolute-bandwidth for all frequency tuning states, a novel T-type bandwidth-control network was devised between resonators to flexibly tune the coupling coefficient without limitations imposed by the available varactor capacitance. By use of tunable source-load coupling, two tunable transmission zeros were produced on both sides of the passband to significantly improve filter selectivity and to dynamically afford interference suppression. A second-order 1.7-2.7 GHz filter with 1 dB constant bandwidth tuning from 50 to 110 MHz and transmission zero locations tuning from 300 to 700 MHz with respect to the passband was developed and fabricated. Good agreement was obtained between the simulated and experimental results.
URI: http://dx.doi.org/10.1109/LMWC.2015.2409794
ISSN: 1531-1309
DOI: 10.1109/LMWC.2015.2409794
Volume: 25
Begin Page: 292
End Page: 294
Appears in Collections:Articles