The real name of these integrated antennas is Meandered Inverted-F Antenna (MIFA). They are engraved on the electronic cards in the form of Zigzags.
Our technical analysis during the design of this device made us exclude this type of antenna, yet compact and fully integrated, because in our opinion they do not respect paragraph I.12 of the article 2 of the Order of 27 December 2019 defining the technical characteristics of the electronic and light signaling devices of aircraft operating without a person on board who provides that the antennas used are omnidirectional.
You can for example watch this article http://www.11echo.com/Antennas/IFA_Meander/ElevenEcho_Antennas_IFA_Meander_Page2.xhtml
You can see there that the antenna does not transmit about 90 ° in the Forward / Backward direction.
For the moment no certification of these devices is required. What will happen to these devices with integrated antenna if this certification becomes mandatory? We don't know!