High-Gain Linearly Tapered Antipodal Slot Antenna on LCP Substrate at E- and W-Bands

In this letter, we present a high-gain linearly tapered antipodal slot antenna (LTASA) on a thin-film liquid crystal polymer (LCP) substrate for E- and W-band applications. The proposed LTASA consists of a microstrip (MS) line feed, an MS-to-antipodal parallel strip line (APSL) balun, a linearly flared antipodal slot line (ASL), and periodic corrugations. An ultrawideband of from 47 to 110 GHz was demonstrated by full-wave simulation and measurement. To characterize the far fields of the LTASA, we developed an optical far-field measurement system in which the RF signal captured by the LTASA will be upconverted to the optical spectrum for power detection. By utilizing the optical approach, the developed system addresses flexibility, light weight, low profile, and low interconnection loss. A high gain of $16.5 + 1 ~\hbox{dBi}$ , narrow beamwidth, low sidelobes, and low cross polarization were demonstrated for the proposed LTASA from 75 to 95 GHz.