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A frequency reconfigurable antenna based on metamaterial is presented. It is composed of a coplanar-fed straight-line monopole with two double split-ring resonators (DSRRs) of different size disposed at its proximity. Each cell exhibits a negative permeability over a frequency band, which produces magnetic couplings with the monopole that starts to radiate at new bands; the whole structure is now a tri-band antenna. The frequencies over which the two DSRRs exhibit a negative permeability have been arbitrarily chosen to show that the proposed approach can be used to create new operating bands and also to introduce notches. By using a single switch at each metamaterial cell, their effect can be deactivated and the corresponding resonance can be suppressed, resulting in a frequency reconfigurable antenna. Simulated and measured results are presented and good agreement is achieved.

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A reconfigurable Vivaldi antenna is presented. It has a capability to operate in a wideband mode (2-8 GHz) and three different sub-bands (2.5, 5, and 7.5 GHz) by reconfiguring the antenna geometry. The measurement results with ideal switches demonstrate the performances of the proposed designs. The proposed antenna provides frequency agility, which may be useful in future multimode radio systems.