What hazard is created by operating at microwave frequencies?
Microwaves are ionizing radiation
The high gain antennas commonly used can result in high exposure levels✓Bonne réponse
Microwaves are in the frequency range where wave velocity is higher
The extremely high frequency energy can damage the joints of antenna structures
Explication
Microwave stations routinely use dishes and horns with tens of decibels of gain, and power density on the beam axis scales directly with antenna gain, so even a modest transmitter can produce levels far above the exposure limits close to the aperture. Microwaves are non-ionising, wave velocity does not increase with frequency, and RF energy does not mechanically damage antenna joints.