Gigahertz

Gigahertz (symbol GHz) is a unit of frequency equal to one billion hertz (10^9 Hz). The prefix giga- denotes 10^9, and hertz measures cycles per second, so 1 GHz means one billion cycles per second. In terms of time, one cycle lasts about one nanosecond. The term is widely used to describe the rate at which signals oscillate in electronic systems.

Gigahertz is commonly used to express processor clock speeds, wireless radio frequencies, and other high-frequency signals. In computing, central processing units and mobile processors often operate in the gigahertz range, with speeds typically a few hundred megahertz to several gigahertz depending on architecture and thermal limits. In digital circuits, GHz values influence how fast a clock can drive sequential logic and data paths.

In communications and broadcasting, GHz bands cover microwave and millimeter-wave allocations used for point-to-point links, satellite uplinks, and consumer wireless standards such as Wi-Fi and cellular backhaul. Wi-Fi networks commonly use 2.4 GHz and 5 GHz bands, while newer technologies explore higher bands around 60 GHz for short-range high-capacity links.

Notes: GHz measures frequency, not data rate. The angular frequency is related by ω = 2πf. Measurements are typically made with frequency counters, spectrum analyzers, and oscilloscopes. The unit is part of the International System of Units (SI) and is named after Heinrich Hertz, who demonstrated fundamental properties of radio waves.