Title :
Reconfigurable Small-Aperture Evanescent Waveguide Antenna
Author :
Ludlow, Peter ; Fusco, Vincent
Author_Institution :
Inst. of Electron., Commun. & Inf. Technol., Queen´´s Univ. Belfast, Belfast, UK
Abstract :
We present a reconfigurable small-aperture evanescent wave guide antenna. Tuning and waveguide matching to free space are simultaneously achieved by placing a printed iris with a shunt varactor diode connected across the aperture of a below-cutoff waveguide. A design approach using the Imaginary Smith Chart is used to synthesize the antenna. The maximum dimension of the antenna is 0.36λ at 2.49 GHz and it operates over an operating frequency range of 2.05-2.49 GHz with maximum realized gain of 5 dBi. The antenna-due to its small size and compact feed arrangement-can be used in phased array/cognitive radio applications. Also its tuneable return loss characteristics enable it to act as an electro magnetic switch (shutter), or variable RCS aperture.
Keywords :
antenna phased arrays; antenna radiation patterns; cognitive radio; varactors; waveguide antennas; cognitive radio; compact feed arrangement; imaginary Smith chart; phased array; printed iris; reconfigurable small-aperture evanescent waveguide antenna; shunt varactor diode; tuneable return loss characteristics; waveguide matching; Antenna measurements; Apertures; Electromagnetic waveguides; Impedance; Iris; Varactors; Electrically small; evanescent waveguide; imaginary Smith chart; reconfigurable;
Journal_Title :
Antennas and Propagation, IEEE Transactions on
DOI :
10.1109/TAP.2011.2165505
