Pattern-Reconfigurable Antenna Using Low-Profile Electric and Magnetic Radiators

Abstract

A compact antenna based on low-profile radiator pairs with high pattern reconfiguration diversity is proposed in this letter. The antenna consists of four hybrid radiator pairs and a reconfigurable feeding network. By switching the <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on/off</small> states of four positive-intrinsic-negative (PIN) diodes, which are integrated into the reconfigurable network, the activation states of the four radiator pairs can be separately controlled. Each pair employs one low-profile electric radiator (monopole) and one low-profile magnetic radiator for stable directional radiation and structural compactness. As a result, the radiation beam can be electrically and directionally scanned in the horizontal plane ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ϕ-</i> plane). Eight different radiation modes can be obtained within an overlapped bandwidth. A prototype is designed, fabricated, and tested. Good impedance matching and stable directional radiation patterns are achieved over the entire operating band from 3.4 to 3.70 GHz in the measurement. The fabricated antenna features a compact size of 0.46 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">λ_g</i> × 0.46 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">λ_g</i> × 0.13 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">λg</i> ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">λ_g</i> represents the guided wavelength at 3.5 GHz). The proposed antenna is well-suitable for space-limited Sub-6 GHz smart and intelligent applications.