LinkRF
EME and Weak signal communication
Copyright © 2008-2026, Eich Switzerland by Alex Artieda, HB9DRI
DRI-X25W
The DRI-XSeries is a modular family of GaAs — Gallium Arsenide solid-state power amplifiers developed specifically around 10.368 GHz weak-signal and EME operation.
The first product, DRI-X4W, is both a complete 4–5 W EME amplifier and the driver platform for the forthcoming DRI-X25W. The longer-term architecture allows higher RF power to be obtained by combining independent amplifier modules rather than concentrating the entire station power in one very expensive semiconductor.
The central idea is to have a "affordable" battle horse modular pallet producing 25W to later combine 2,3,4,or 5 25W pallets using phase rersonance cavities (silver plated) to obtain as much less IL in the combining process. As a matter of fact if properlly interconection is provided 4 DRI-X25W will produce minumum 90 watts of effective power with a WR-90 output direct into the wave guide antenna relay
To desing a modular pallet many central topics become "problematic", the selection of the device: GaAs vs GaN, the properly pcb and the way is design and grounded in the enclosure, the enclosure per se with negative resonance problematic almost ignored by the amateur builders, last at not least a properly electronics to manage specially the temperature and Id based on a MCU insted of simple analog circuits.
Contrary to most of the ham radio desings, where a single pcb host 2 to 3 active devices, branch line combiners and the full electronic to regulate the Vd and Vg, the DRI-X25W looks like that:
The internal cavity is just 96.2mm x 25mm x 12mm and it was desing using the RESOBOX software, a propietary software desing by my self to analyse resonance point in the TE and TM fields, the DRI-X4W was desing using my software and when I close the lid the SSPa increasi his power by 5% aprox, contrary to many amateur desing where misterious resonace are not in consideration, closing the enclouser always give you 10 to 40% less power, forcing you to use "RF abosrber material" to compensate the poor enclosure desing.
As you see in the previous picture the propose cavity for the DRI-X25W will have resonace points at 5.18% and 5.20% away from 10.368 GHz, the minImum practical separation must be at leat 2.8% otherwise you will have oscillations and low power when you close the enclosure, forcing you to use RF absorber materials with not 100% good results.
The DRI-X25W is in the final stage and I hope to publish my first practical results in 5 to 6 weeks aprox. PCB are ready and now is a mater to buid, the CNC enclosure,and present all parts inside.
MORE TO COME!!