Cell phone
Definition
A cell phone is a portable electronic device that uses electromagnetic waves to enable wireless communication. It operates within specific frequency bands of the electromagnetic spectrum.
5 Must Know Facts For Your Next Test
- Cell phones primarily operate using radio waves, which are part of the electromagnetic spectrum.
- The frequency range for cell phone communication typically falls between 700 MHz and 2.6 GHz.
- Cell phones convert voice signals into electrical signals, which are then transmitted as electromagnetic waves.
- The efficiency and range of a cell phone signal can be affected by factors such as interference and obstacles like buildings.
- Modern cell phones often use digital modulation techniques like Quadrature Amplitude Modulation (QAM) to improve data transmission rates.
Review Questions
- What part of the electromagnetic spectrum do cell phones use for communication?
- How do obstacles like buildings affect cell phone signal transmission?
- Why are digital modulation techniques used in modern cell phones?
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Related terms
Radio Waves: A type of electromagnetic wave with frequencies ranging from about 3 kHz to 300 GHz, used for long-distance communication.
Frequency: The number of cycles per second in an electromagnetic wave, measured in Hertz (Hz).
Digital Modulation: \text{Techniques used to encode information onto an electromagnetic wave by varying its amplitude, frequency, or phase.}
