Circularly polarized dielectri-loaded antennas: Current technology and future challenges

In the last few years, dielectric loaded antennas (DLAs) have emerged as a viable solution for high-gain reception at microwave frequencies for handheld devices such as satellite phones, radios, and global positioning systems. This article compares the performance cost and volumetric efficiencies of the two dominant designs namely the dielectrically loaded quadrifilar helix and microstrip patch antennas. The current and future material requirements for DLAs are discussed and an example is given of a recently developed castable glass ceramic based on BiNbO4, which is suitable in terms of properties and glass formability for the single-step fabrication of net-shape antenna cores.