Differential Stepped-Slot UWB Antenna With Common-Mode Suppression and Dual Sharp-Selectivity Notched Bands

A differential stepped-slot UWB antenna with common-mode suppression and dual sharp-selectivity notched bands is proposed in this letter. The antenna adopts stepped slot as radiator to achieve ultrawideband. Under differential-mode operation, the stepped slot can be effectively excited by feeding microstrip, and differential signals can be radiated. However, under common-mode operation, the stepped slot would not be excited so that the common-mode suppression can be achieved. In order to achieve dual sharp-selectivity notch-band characteristic, quarter-wavelength slits are etched on the ground, and half-wavelength stubs are introduced beside the microstrip, respectively. As a result, dual second-order notched bands with sharp selectivity are obtained. The measured results show that the proposed antenna obtains good common-mode suppression characteristic and dual sharp-selectivity notched bands from 5.1 to 6.0 GHz and 7.83 to 8.47 GHz. Good agreement is achieved between the measured results and the simulated results.