[i‚fek·tiv ‚ī·sə‚träp·ik ‚rād·ē‚ād·əd ′pau̇·ər] (communications) A measure of the strength of the signal leaving a satellite antenna in a particular direction, equal to the product of the power supplied to the satellite transmit antenna and its gain in that direction. Abbreviated eirp.SeeEIPRSeeEIRP