A Shallow Varactor-Tuned Cavity-Backed Slot Antenna With a 1.9:1 Tuning Range

作者：White Carson R^*; Rebeiz Gabriel M

来源：IEEE Transactions on Antennas and Propagation, 2010, 58(3): 633-639.

DOI：10.1109/TAP.2009.2039311

• Cavity backed antennas
• reconfigurable antennas
• slot antennas

A shallow (0.025 wavelengths) microstrip-fed cavity-backed-slot (CBS) antenna has been demonstrated that tunes from 1 to 1.9 GHz with better than -20 dB reflection coefficient using a single varactor diode (0.45-2.5 pF). This is possible because the slot and the cavity combine to form a single resonance, and therefore, do not need to be tuned independently. The cavity is 72 x 72 x 3.18 mm(3), and is dielectrically loaded (epsilon(r) = 2.1). The impedance match over the tuning range has been achieved by searching for combinations of feed and varactor locations for which the impedance is matched to 50 Omega by a single series inductor, and the input impedance is nearly identical whether the antenna is in free-space or conformally mounted on a 1.2 x 1.2 m(2) ground plane. The cross-polarization is better than -25 dB at 1.0, 1.5, and 1.9 GHz. To the authors' knowledge, this is the first demonstration of a varactor-tuned CBS antenna.

• 出版日期2010-3