Nicolas Delhote

Ceramic Layer-By-Layer Stereolithography for the Manufacturing of 3-D Millimeter-Wave Filters

Three-dimensional (3-D) ceramic stereolithography has been developed and used to manufacture RF devices using periodic structures. To our knowledge, it is the first time that zirconia and high-performance Ba3ZnTa2O9 ceramics are used with that process to manufacture high unloaded quality factor resonant structures and bandpass filters working in the Ka-band. A theoretical study on the performances of periodic arrangements of high-permittivity structures has been carried out and has led to the manufacture of a high unloaded quality factor cavity and narrow three-pole filter (1% bandwidth) measured at a working frequency of 33 GHz

Electromagnetic-Bandgap Waveguide for the Millimeter Range

This paper presents the design, manufacturing, and characterization of a waveguide based on electromagnetic-bandgap (EBG) technology working in W-band. A modified silicon EBG woodpile structure was used in order to improve the matching performance of the EBG waveguide to a standard rectangular waveguide. The transition between the silicon EBG woodpile waveguide and the conventional WR10 waveguide was optimized and a 13.5% bandwidth around 90 GHz was achieved. The measured insertion losses remained better than 3 dB in the overall working bandwidth.

Topology optimization applied to the design of a dual-mode filter including a dielectric resonator

The finite element method is coupled with the topology gradient method for optimizing the shape of microwave components using a numerical model. The approach, which consists in minimizing a cost function with respect to the physical property of individual topological elements, is first described. Regarding given electrical specifications, the technique is applied for optimizing the distribution of dielectric material in 3D in order to improve the behavior of a classical dual-mode filter including a dielectric resonator.

Shape optimization design and ceramic stereo-lithography process dedicated to microwave component manufacturing

In this paper, the topology gradient is applied in 3D for optimizing the shape of dual-mode dielectric resonators, and improving the electrical behavior of these classical filter components. Reference and optimal dielectric resonators are then fabricated by a 3D ceramic stereolithography process.

Advanced Design and Manufacturing of Microwave Components Based on Shape Optimization and Ceramic Stereolithography Process

A design technique based on a shape optimization strategy (topology gradient algorithm) and a 3D ceramic stereolithography process are described in this paper. Our goals are to propose innovative components in terms of electric performances and topologies, by using these two approaches together. Several components have been designed, manufactured and tested with success. An example is given for the design of microwave filters including dielectric resonators.