Industry Days - Additive Manufacturing for RF/Microwave hardware

Compact Evanescent Rectangular Waveguide Dual-Channel Bandpass Filters for Additive 3-D Manufacturing (Universidad Politecnica de Cartagena)

22 Nov 2016, 16:25

25m

NA052 -Erasmus Conference Room (ESA/ESTEC)

Speaker

Mr Alejandro Pons Abenza (Universidad Politecnica de Cartagena)

Description

In this contribution a novel evanescent waveguide dual-channel bandpass filter is proposed. The structure is suitable for additive manufacturing as the inner evanescent structure containing elliptical posts attached to a metallic wall is placed in the middle of a standard waveguide. Since the whole filter should be manufactured as a single piece, only additive manufacturing is able to reproduce the complex geometry required for the practical realization of this structure. From the electrical point of view, the proposed structure has a number of advantages as compared to the state of the art technology. One of the main advantages is the flexibility in the type of transfer functions that can be achieved. This ranges from standard Chebyshev responses to dual-band responses implementing transmission zeros for maximum isolation between channels. This type of structure has never been used before due to manufacturing limitations, that can now be overcome by using emerging additive manufacturing techniques.

JUSTIFICATION FOR THE CONSIDERATION

In this work, we present a new filter structure with many advantages as compared to state of the art technology, and that can benefit from the use of 3-D additive manufacturing techniques. The structure consists of a complex geometry incorporating two evanescent mode channels with elliptical posts. The manufacturing of this structure with standard machining techniques is almost impossible. This has prevented up to now to exploit in practice the proposed concept. With the use of emerging 3-D additive manufacturing techniques, the practical realization of the proposed device is now possible.

The advantages of the proposed structure are the compact size as compared to standard waveguide technology, and the flexibility in the type of transfer functions that can be implemented. Slight design modifications can lead to Chebyshev responses or dual-band responses with transmission zeros (to cite two examples). An additional advantage is that tuning screws can be easily accomodated in the structure to correct for possible innacuracies derived from the use of 3-D additive manufacturing techniques. During the workshop, all the advantages of the proposed structure will be explained together with those derived from the use of 3-D additive manufacturing techniques.