Reconfigurable H‐plane waveguide phase shifters prototyping with additive manufacturing at K‐band

Abstract

This work presents the design and manufacturing of a K‐band reconfigurable phase shifter completely implemented in waveguide technology for reduced insertion loss, good matching, and large phase shifting range. The device is based on the combination of a short slot coupler and two tunable reactive loads implemented as a section of short‐circuited waveguide where an adjustable metallic post is inserted. Three prototypes of this design have been manufactured using different techniques (conventional computer numerical control machining, a low‐cost fused filament fabrication technique and direct metal laser sintering) in order to assess its performance for different applications. The prototypes have been characterized experimentally and the achieved results are evaluated and compared. The proposed phase shifter, since it is fully developed in waveguide technology, eliminates the need of adding transitions to planar structures in order to integrate lumped components like pin diodes or varactors. Therefore, this device has a great potential in high‐power beam steering phased arrays.

Mechanically Reconfigurable Linear Phased Array Antenna Based on Single-Block Waveguide Reflective Phase Shifters With Tuning Screws

“…Different kinds of waveguide structures can be used to implement the 90 ○ hybrid coupler part of the WRPS. For example, the Riblet short-slot hybrid junction is known to produce a very compact device [34], [35] and it was indeed used by the authors in a previous work [32]. Other alternatives can provide better performance (in terms of bandwidth) [36], as is the case of the coupler used in the present work.…”

“…Regarding the design in [33], the lower insertion losses in comparison with the proposed design are explained by the manufacturing using conventional machining instead of DMLS. As shown by [32], if the phase shifter presented in this work were manufactured using conventional machining the obtained insertion losses would be lower. The results for the other phase shifters of the module are omitted since they are identical.…”

“…In this work a waveguide 90 ○ hybrid coupler where two of its ports are loaded by a tunable reactive load completely implemented in waveguide technology [32], [33] is proposed. This load consists of a short-circuited waveguide section where a TS is inserted.…”

“…As it will be shown, this phase shifting range is enough to adequately scan the main lobe of the radiation pattern produced by the array. If necessary, the phase shifting range could be increased by placing the TS closer to the short-circuit [32]. For this specific design this range could have been increased up to 310 ○ by placing the screw at 0.5 mm of the shortcircuit.…”

Low-Loss Reconfigurable Phase Shifter in Gap-Waveguide Technology for mm-Wave Applications

“…Waveguide technology is a good candidate since it provides reduced losses in the mm-wave frequency range. Some examples of mechanically reconfigurable phase shifters in waveguide technology at K-band can be found in [2], [3]. In both designs, short waveguide couplers with mechanical reconfigurable elements at the output ports have been used to achieve the desired phase shift in reflection.…”