Inkjet-Printed Filtering Antenna on a Textile for Wearable Applications

This paper has presented an inkjet-printed filtering antenna on a textile substrate for wearable electronics. In order to improve the porous of textiles, screen-printed interface layer (Fabink-UV-IF1) was used to obtain the uniformity of surface on an textile. The optimal wettability of interface layer for subsequent inkjet printing was obtained by using post-baking. Inkjet-printed conditions of silver film on a textile with interface layer were examined by surface morphologies and electrical properties. Based on optimal conditions, inkjet-printed filtering antenna was design and implemented using silver ink. Two open stubs were used to produces two transmission zeros near the passband. The frequency band was 2.5 - 4.6 GHz with the maximal gain of -0.42 - -3.1 dBi for voltage standing wave ratio was less than 2. Two rejection frequencies at 1.6 and 5.7 GHz were found because of two open stubs. The characteristics of two bending directions for the filtering antenna were also studied. The size of the filtering antenna was 37.5 mm × 23 mm × 0.49 mm. The results demonstrated the integrity of inkjet-printed technology which combination of wearable and printed electronic applications.