Preferably, the microwave radiation is at {TAIL ~ a frequency} of {HEAD ~ from twenty to 3000 MHz} 
Preferably , the microwave radiation is at { TAIL ~ a frequency } of { HEAD ~ from twenty to 3000 MHz }
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD