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.
A castable, low melting temperature glass-ceramic system (30% Bi 2 O 3, 30% Nb 2 O 5, 30% B 2 O 3 and 10% SiO 2, in mol%) suitable for microwave applications is fabricated and characterized. Depending on heat treatment temperature, the glass ceramic exhibits permittivity, 15 ≤ ε r ≤ 41, temperature coefficient of resonant frequency of -160 ≤ τ f ≤ +100 MK -1 and microwave quality factor of 300 GHz ≤ Qf ≤ 15000 GHz . The highest Qf occurs at 960°C heat treatment with ε r = 15, τ f = -80 MK -1 and Qf = 15000 GHz . Applications are envisaged such as castable dielectrically-loaded antenna pucks, removing the need for complex ceramic processing.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.