A Low-Profile Frequency Reconfigurable Antenna with Polarization and Pattern Diversity

In order to satisfy modern diverse communication requirements, a low-profile frequency reconfigurable antenna with polarization and pattern diversity is proposed. Two different metamaterial inspired reconfigurable structures are designed and integrated in a single antenna. The so-called 1 mode of an outer annular right/left-handed transmission line (CRLH-TL) based radiator provides a broadside radiation pattern. The so-called 0 mode of an inner circular radiator loaded with split ring resonators (SRRs) provides an omni-directional radiation pattern. Polarization and pattern diversity are thus achieved. These two radiators are continuously tuned with varactors to realize frequency reconfigurability in a tuning range from 1.7 GHz to 2.2 GHz. The antenna has a low profile of 0.042 λ. For demonstration, a prototype antenna is implemented. Simulations and experiments match well.