I've been watching folks discuss RFSPACE's Vivaldi antenna's on Twitter a lot over the past few weeks and became interested in witnessing the performance of this type of antenna for myself, but I can never catch them with any in stock. So I decided to make a few of my own to use with my N3 SDR, AirSpy Mini, and RTL-SDRs.
I searched high and low online for some designs to use with no luck. So, like I normally do, I jump right in and see how bad I can screw it up on my own!
At a recent hamfest I aquired a good amount of different sized copper PCB for nearly nothing ($10 for roughly ~20 lbs or so of boards). I originally made the designs to use with the toner transfer method, but was convinced by Adam to try the scissor/cutout method. Among all that PCB were some 25.5cm x 18cm "scissor cut" boards that would be a good start. My initial target is for the L-Band, Inmarsat and Irridium primarily, and work up from there.
I've downloaded several PDF's on the subject of Vivaldi's and their types and designs but have yet to read them. I jumped right in using Gimp and Paint as that is what I had available at the time. The files below may or may not work at my targeted frequencies, but a person has to start somewhere. I'll do some reading on those PDFs this week.
Contructive cristicism is more than welcome in the comments.
File sizes on the two larger ones at 18cm x 25cm, you may want to reduce them in your image program to suite your material or frequency needs. I'd smooth the internal edges out at production time, depending on your method. I'll add better designed ones in the future, so check back if interested.
Hopefully you'll find these useful.
73 for now. Chris – KD0CQ