Properties of phase-modulable sealant of flexible RF microstrip line
To meet the phase-modulable characteristics of all-printed RF MSLs in application,the curing agent polyetheramine D-230 with good molecular chain flexibility was introduced to prepare a high-reliability phase-modulable sealant.The phase modulation mechanism,reliability,and its effect on the performance of the RF MSLs were investigated.The results show that this sealant exhibits superior dielectric properties,mechanical properties,thermal stability with low water absorption.The dielectric constant and dielectric loss are below 2.5 and 2.2 in the 1-4 GHz frequency range,respectively.Furthermore,the obtained RF MSLs realize phase-modulable characteristics by applying a small amount(approximately 1 mg)of the sealant to their surface.The value of the phase lag at 4 GHz is 14.1°.The process exhibits low cost and flexible operation,and the flexible modulation of phase can be realized without external rigid phase shifters or phase-shifting networks.This study provides an innovative approach for the phase consistency adjustment of the flexible radio frequency devices.