Beam In Elevation Plane Research Articles

Enhancement of Tilted Beam in Elevation Plane for Planar End-Fire Antennas Using Artificial Dielectric Medium

This communication describes a simple and effective beam-tilting technique for planar end-fire antennas using an artificial dielectric layer. The proposed approach is based on the phase differential resulting from a high refractive-index medium that is achieved using double G-shaped resonators (DGRs) in a ${5} \times {4}$ array. The array is oriented normal to the direction of the main beam emanating from the antenna. To demonstrate the principle, the technique is applied to a bow-tie antenna, which is designed at the WiMAX frequency band (3.4–3.6 GHz). The antenna performance was verified practically, and the measured results confirm that the direction of antenna’s maximum beam can be refracted by 35° in the H-plane, which is larger than conventional techniques. In addition, a maximum gain enhancement of 5 dB is achieved when the beam is tilted. Reflection-coefficient of the proposed structure is maintained better than $- {10}\;\text{dB}$ across its operational band.

A Phased Array Antenna Using Ferroelectric CPW Phase Shifter Active Modules

A phased array antenna using ferroelectric coplanar waveguide (CPW) phase shifter active modules is presented based on a Ba0.6Sr0.4TiO3 (BST) thin film. The ferroelectric BST thin film was deposited on an MgO substrate by using pulsed laser deposition. The active module amplifies an RF signal with low noise and changes the phase of a received RF signal to control the main beam of the array antenna. It is composed of low noise amplifier (LNA), dc block, and ferroelectric CPW phase shifter. The prototype of 6×12 phased array patch antenna with the active modules using a ferroelectric phase shifter is proposed. The proposed array antenna continuously scanned its main beam in elevation plane to 32° from its broadside direction at 11.85 GHz by applying the continuous dc voltage to the ferroelectric phase shifter.

Elevation Plane Beam Scanning of a Novel Parasitic Array Radiator Antenna for 1900 MHz Mobile Handheld Terminals

A novel internal antenna system is introduced for the GSM 1900 MHz frequency band which utilizes the electrically steerable parasitic array radiator (ESPAR) concept to steer the elevation plane beam in specific angular directions. The proposed antenna consists of a planar inverted-F antenna (PIFA) as the driven element and two inverted L antennas (ILAs) as parasitic elements. The ILAs are terminated with capacitive impedances at their bases. Full-wave analysis shows that the radiation beam can be scanned in space when the antenna is in free space as well as next to human head and hand phantoms. Measured results using varactor diodes controlling the base reactances show good return loss bandwidth.