Design of Printed Monopole Antennas on Liquid Crystal Polymer Substrates

In this paper, a compact printed monopole antenna with an extremely wide bandwidth has been realized on Liquid Crystal Polymer (LCP) substrates by using standard processing technology. Both laminated and directed metalized LCP substrates were used in this experiment. The antenna made on the direct metalized LCP substrate performed well compared to on the laminated LCP substrate. To improve the adhesion, the surface of the LCP was further roughened and a certain adhesion layer was used prior to the deposition of Cu. The measured antenna on a metalized LCP substrate could cover this frequency band with an impedance bandwidth from 0.51 GHz to 14.4 GHz (28.2:1) for VSWRa parts per thousand currency sign2. Moreover, the antenna exhibits a nearly omni-directional radiation pattern. The size of this antenna is only about 0.18 lambda(1) x 0.13 lambda(1), where lambda(1) is the wavelength of the lowest operating frequency. The results show that LCP is a promising candidate for high frequency applications.