Kalus,
I use it for radiated work above 900 MHz. I have done radiated immunity and wire induced immunity testing at lower frequencies. It is also great for RF measurements to test radio sensitivity.
TEM cells have an upper frequency limit based on the dimensions. If you are handy and creative, you can build one yourself. Or, if you have access to a sheet metal shop. You can build it from galvanized heating duct materials. This article is pretty good. untitled (chaosproject.com)
I am contemplating a LISN. I built one a long time back. – WARNING, Always use an attenuator between the LISN and your spectrum analyzer as well as not switching things while the analyzer is connected. The spikes will blow out the front end of the spectrum analyzer. I worked with guys that did it twice!
I have a couple of similar antennas from Printed Circuit Board Antennas| Commercial and Hobby Antennas (wa5vjb.com). They work pretty well. That one should also.