The 24GHz DIY wave guide switch/relay in WR42.

This page reports on an ongoing project. It is not finished yet. It is very interesting to work on.

Wave-guide switches are hard to get. The 10 GHz ones are hard to find, but the 24 GHz wave guide relays are nearly impossible to find. Good reason to give it some thought if we can make one ourselves. The basic idea was that production could be done in a makers lab or in a fablab.

A quick search on the internet offers one design by W1RIL unfortunately a SK. The page is hosted by the WA1MBA and can be found here.

Version 1

Things were started slowly with some help from my son in law Bas who is a mechanical engineer the first drawings were made. Things started in the summer of 2023. With the coming of a 3D printer first items became physical and could be improved.

The first 3D printed parts.
The bottom part of the WG switch with the bearing pressed in.
The bottom plate of the rotor.

The next step was to make the rotor drawing and have that made in the fablab.

The rotor in WR42 format
Rotor in WR42 side view
Bottom of the body and rotor cover plate and rotor
Almost complete.

By putting the switch together I quickly noticed that some dimensions were not correct. The holes for mounting the WG-flanges were not deep enough so the whole body was enlarged now measuring 50 x 50mm. The rotor remained the same. 2 out of 4 parts were redesigned and milled.

Version 2

When the parts arrived it was quickly fitted together. To make it fit nicely some minor changes were necessary. The whole thing didn’t rotate smooth so 0.1mm was removed in several places. It all came out very nicely and really something to be proud of. Next will be the RF testing of the switch!

Version #2 of the wave-guide switch

Part 3 The measurements

The measurements were done by Jack PE1KXH. The results look very good. The isolation measurements are limited by the dynamic range of the measurement.

The measurement setup @ PE1KXH
Insertion loss of the WG switch 0.3dB @ 24 GHz.
Isolation of the WG switch >50dB limited by the dynamic range of the detector. Sorry for bad photo.

Part 4 Measurements at the Dorsten UKW Tagung 17 Feb. 2024

Isolation with 45 degrees