A New Low Loss Rotman Lens Design Using a Graded Dielectric Substrate

Novel 3D printed synthetic dielectric substrates

“…Traditional mechanical machining and micromachining have been up to now the dominant approach for fabrication [6,7]. These machining techniques remove or shape parts of raw materials using operations such as drilling and milling.…”

“…[4] and XG-PON in ITU-T G.987 [5] rec. All these PON types mentioned above are based on time-division multiplex (TDM) principle while both upstream and downstream TDM frames consist of multiple contributions to/from all active end-points optical network units (ONUs) [6]. Therefore, a part of the optical distribution network (ODN) is always shared by multiple ONUs.…”

Applications and Future Prospects for Microstrip Antennas Using Heterogeneous and Complex 3-D Geometry Substrates

“…Synthesized dielectrics with both small and large sized holes produced identical radiation patterns [23]. Rotman lenses [24] are an important component of many beam forming networks and have been utilised in various applications including multi-beam receivers, beam steering antenna systems and automotive radar systems [25,26]. Heterogeneous dielectrics have been employed to reduce the insertion loss in comparison with a homogeneous substrate Rotman lens.…”

“…A gradient of permittivities, as indicated in Figure 3(a), was synthesized by varying the density of drilled holes in the substrate and used to bend the rays with in the lens for improved focussing. This also decreased the power loss due to spill-over to the side ports [26]. Layered heterogeneous substrates, as in Figure 3(b), were synthesized using low temperature co-fired ceramics (LTCC) processing.…”

“…(a) A perforated dielectric slab where the density of air-filled holes varies the effective permittivity (redrawn from [26]); (b) the darker part indicates the section from which the substrate has been removed. The direction of electric field is along z-axis for (i) and y-axis for (ii) (redrawn from [27]).…”