KEYNOTE: Aurora: Advancing the Radio Art

The FlexRadio “Aurora” is a state-of-the-art amateur-radio transceiver that operates from 1.8 to 54 MHz, producing 500 W output with an overall efficiency of 80 percent. Employing a combination of envelope elimination and restoration and a high efficiency class-D RF power amplifier, it brings a significant reduction in size, weight, and power to this transceiver class. The evolution of the engineering design from a hobby project to a completed commercial product is detailed, highlighting the continued contribution of the Amateur Radio Service to the advancement of the radio art.