Effect of human body on wireless microphones transmission

[henrimic]

I have recently upgraded my A10-RX to a new A20-RX.

The idea is to move from the crowded UHF band to the 1.3 GHz band and to reduce the lenght of the antenna on the A20-mini transmitters.

As I was searching technical informations about the effects of obstacles, and especially human body, on the transmission at higher frequencies, I found this very interesting study:

 

https://www.bakom.admin.ch/bakom/en/homepage/frequencies-and-antennas/facts-and-figures/the-effect-of-the-human-body-on-wireless-microphone-transmission.html

 

If I understand well, if the body is an absorber in the UHF band, it acts more like a reflector at higher frequencies.

 

I will try to work in the 1350 MHz range next week and I'll let you know if I see an improvement in the transmission at these frequencies.

 

 

[Rick Reineke]

I do not think a few thousand Hz will make any difference. I just try to avoid having an antenna touch bare skin which can attenuate an RF signal significantly.

[Patrick Farrell]

Their point of reference for radiated power increasing is 3 GHz. The effect will be much less pronounced at 1350 MHz. Also note they say shadowing increases with the frequency. So if you hide the pack on talent's back, you'll get a stronger signal with their back to you but relatively less when they face you which means greater fluctuations and a less stable signal.

[henrimic]

Back from my first shoot with the A20 mini and A20-RX in the 1350 MHz band. So far, I haven't noticed any difference in range compared to UHF.

I put the transmitter in the front pocket of the talent and had no problems, even when he was walking quite a distance away, from behind.

His body seems not being a more noticable obstacle, which is good news.

The real advantage is that the antenna is now really tiny, about 2 inches, and that makes a real difference to hiding the transmitter.

Not to mention that the band was totally clear when I scanned it.

[Soundwil]

Thanks for reporting your findings Henrimic, very interesting.