A Leaky-Wave Magnetoelectric Antenna With Endfire Radiation for Millimeter-Wave Communications

Abstract

A millimeter-wave (mmWave) leaky-wave antenna (LWA) with a wide bandwidth and stable endfire radiation is proposed. It is demonstrated that by loading a dipole array at the aperture of a half-mode substrate integrated waveguide (HMSIW) LWA, the phase constant of the leaky HMSIW can be tuned from <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\beta &lt; k_{0}$ </tex-math></inline-formula> to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\beta \ge k_{0}$ </tex-math></inline-formula> , thus enabling the desired endfire radiation. The dipole array and the leaky HMSIW jointly form a complementary pair of sources that can yield wideband performance with improved gain. To validate the design concept, a prototype with a radiating length of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$4.17 \lambda _{0}$ </tex-math></inline-formula> and a width of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.2 \lambda _{0}$ </tex-math></inline-formula> is designed and fabricated. Experimental results verify a wide impedance bandwidth of more than 40%, a 3 dB gain bandwidth of 24%, and an endfire gain of up to 13.9 dBi. Owing to the merits including wide bandwidth, improved gain, and compact planar structure, the proposed antenna is attractive for mmWave wireless applications.