In 1958 he retired but continued as a research consultant to the Hewlett - Packard Company as a friend of David Packard .
In 1946 Friis published his well - known analytic formula for transmission loss , the Friis transmission equation , which is still widely employed .
In 1958 Friis retired but continued as a research consultant to the Hewlett - Packard Company as a friend of David Packard .
In 1946 Friis published his well - known analytic formula for transmission loss , the Friis transmission equation , which is still widely employed .