I got an RF generator R&S HAMEG HM8135 that I use in a testsystem to generate FM and AM stimuli in order to check if FM antenna and AM antenna is correctly mounted on the testobject in a production line. Therefore I do transmitt with as low RF power as possible. Due to spacing and production considerations, I can only have one common antenna place quite close to the test object.
I do use a Schwartzbeck HFRA 5155 TX Loop antenna covering 100 kHz to 300 MHz, which will work for both FM and AM band range. HFRA 5155
However, if I look in the datasheet, I can see that the impedance around 100 MHz is about 50 ohm, but for 1MHz, it is only about 3 ohm. My test system works (I need so weak AM signal to detect if antenna is not solded correctly, but needs to run the RF generator at about 0 dBm), but my concern is that since I do have so low impedance at 1 MHz (AM test), there must be a lot of power reflecting back into the RF generator (R&S HAMEG HM8135).
- What impact does the low impedance at 3 ohms for 1 MHz have on my RF generator? Can it be damaged?
- Do I need to add anything in order to protect the generator? I do not want to change the RF setup like using two antennas or switching. Just something simple.