Design of a 3-D Integrated Wideband Filtering Magneto-Electric Dipole Antenna

Abstract

A new design of 3-D integrated wideband filtering magneto-electric dipole antenna with high selectivity is presented. The proposed antenna is mainly composed of a horizontal planar dipole and a vertically oriented shorted patch antenna. A pair of C-slots is etched on the planar dipole to obtain sharp skirt selectivity near both band-edges. In addition, a slotline loaded with the patch antenna provides good impedance matching. The proposal exhibits a quasi-elliptic gain response with three introduced radiation nulls without additional filtering circuits. To verify the design concept, a prototype is fabricated and measured. The result exhibits an impedance bandwidth of 55.4% with <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text {SWR}\le 1.5$ </tex-math></inline-formula> from 1.58 to 2.79 GHz. Moreover, the low back radiation levels ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${\le } -16$ </tex-math></inline-formula> dB), stable radiation patterns with low cross polarization levels ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${\le } -26$ </tex-math></inline-formula> dB), and an average antenna gain of 7.8 dBi are achieved within the operating band. In addition, an out-of-band suppression level, better than 17 dB, is reached.