IEEE Spectrum March 10, 2020
Conventional sabre-like antennas generate a donut-shape radiation pattern, which provides an omnidirectional coverage and is ideal for air-to-ground communication. However, a donut-shape pattern has a null at its zenith which inhibits communication with other satellites. To provide signal directly above the antenna researchers in China designed a novel sabre-like antenna incorporated two metal radiators into the design. The first is a monopole, which is perpendicular to the ground with an omnidirectional pattern. The second is a dipole, which is parallel to the ground with broadside pattern – creating a signal that fills the blind spot of conventional antennas. The two radiators generate two working modes and desired radiation patterns and provide a capacitor loading effect, which shrinks the antenna size. The antenna can switch between two modes on the fly, and thus provides top hemisphere coverage…read more. TECHNICAL ARTICLE
A conventional donut-shaped radiation pattern. Credit: Tsinghua University; UAV: Shutterstock