Zendvermogen

Zendvermogen is the average RF power that a radio transmitter delivers to the antenna system. It is typically expressed in watts (W) and can also be stated in decibels relative to one watt (dBW) or decibels relative to one milliwatt (dBm). Zendvermogen reflects the transmitter’s output setting and the losses in the transmission chain up to the antenna; it is not necessarily equal to the power that is radiated.

Not all zendvermogen becomes radiated power. The portion that is radiated depends on the antenna’s efficiency and on losses in the feed network, impedance matching, and the transmitter itself. The radiated power P_rad can be described as P_rad = η × P_input, where η is the antenna’s radiation efficiency and P_input is the power delivered to the antenna input. The difference is dissipated as heat in components or lost in transmission lines.

A closely related concept is the effective radiated power (EIRP). EIRP equals the power delivered to the antenna input multiplied by the antenna gain relative to an isotropic radiator (G). In practice, EIRP provides a direction-dependent measure of signal strength and is used in regulatory and planning contexts. ERP is a comparable metric using a dipole reference and is typically about 2.15 dB lower than EIRP for the same system.

Zendvermogen is a standard specification in radio equipment and licensing. It influences coverage and interference potential, and is considered together with antenna gain to determine overall radiated field strength.