Microwaves and Infrared Radiation

Microwaves

• Frequency range: roughly $10^9$ Hz ($1$ GHz) to $3 \times 10^{11}$ Hz.
• Wavelength range: approximately $30$ cm to $1.0$ mm.
• Wavelengths from less than $1$ cm to about $30$ cm can penetrate Earth's atmosphere.
• Key uses: Space-vehicle communications, radio astronomy, satellite communication (telephone/cell phone), airplane communication, television station communication.

Infrared Radiation

• Frequency range: merges with microwaves at around $300$ GHz ($1.0$ mm wavelength) and extends to about $385$ THz ($780$ mm wavelength).
• Nature: Heat radiation.
• Key uses: Television remote control units, motion detectors (security devices).