Microstrip antenna with radiation pattern selectivity and polarized diversity based on modified metamaterial structure

In this paper microstrip antenna with linear polarization (LP) for monopolar radiation pattern mode and circular polarization (CP) for patch-like radiation pattern mode is presented. The introduction of modified metamaterial structure enables antenna with this function. Equivalent evolutionary approximation of the proposed antenna from CRLH TL theory is used to analyze the operating principle. Both simulated and measured results of a proposed one confirm the predictions of the theory. Comparing to the former dual-mode and dual-polarized antennas, this one owns compact structure and good radiation properties besides radiation pattern selectivity and polarized diversity.