(W/Hz) stands for watts per hertz. It is a unit of power spectral density, which represents how power is distributed across different frequencies. Here’s a breakdown:
- Watt (W): The watt is the SI (International System of Units) unit of power. It indicates the rate of energy transfer or conversion.
- Hertz (Hz): The hertz is the SI unit for frequency, representing cycles per second. It measures the number of times a periodic event occurs in one second.
- Watts per Hertz (W/Hz): When discussing power spectral density (PSD), the power of a signal (in watts) is spread over different frequencies (in hertz). The unit (W/Hz) indicates how much power is present for each unit of frequency.
For instance, if a signal has a power spectral density of 2 W/Hz at 500 Hz, it means that around the frequency of 500 Hz, there are 2 watts of power for every hertz.
This unit is especially prevalent in contexts where the power distribution of a signal across frequencies is being described, such as in signal processing, telecommunications, and related fields.