Vivaldi’s are linearly polarized broadband antennas that have a directional radiation pattern at higher frequencies. The high end SDR manufacturer RF Space produces their own Vivaldi antennas made from PCB boards which they sell online. The larger the antenna, the lower its receiving frequency, and ones that go down to about 200 MHz are almost the size of a full adult person. But all sizes receive up to 6 GHz maximum. Typically smaller versions of Vivald antennas have been used in the past for L-Band satellite reception.
Over on his blog KD0CQ noted that he always had trouble trying to purchase a Vivaldi from RF Space because they were too popular and always out of stock. So he decided to try and build his own out of PCB boards. On this page he’s collected a bunch of Vivaldi cutout or transfer images. On his second page he shows a Vivaldi antenna that he built out of PCB material, just by using scissors and semi-rigid coax. With the Vivaldi placed outdoors he’s been able to successfully receive and decode L-Band AERO on his Airspy Mini even without an LNA.
KD0CQ writes that he’ll update his blog soon with more results.