UWB flexible filter with low loss and excellent stopband performance.

ABSTRACT The compact UWB flexible filter with low loss and excellent stop band suppression on ultrathin liquid crystal polymer substrate is presented firstly. A uniform microstrip line connected with five pairs of stubs is used. The flexible filter with the pass band of 4.1-10.6 GHz. The measured minimum insertion loss is 0.76 dB at 5.4 GHz and the return loss is better than 11.3 dB. While the frequency is higher than 12.1 GHz, excellent high resistance band suppression is obtained. The bending behavior of the UWB flexible filter is analyzed. In case of R = 17.5 mm, the insertion loss is only improved by 0.004 dB and the return loss is optimized by 0.45dB. Good agreement is obtained between the flat and the bending. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:194-197, 2017 [ABSTRACT FROM AUTHOR]