AVIDrone's unmanned aircraft system competing in DARPA's Lift Challenge. Photo: DARPA

The Defense Advanced Research Projects Agency (DARPA) this week announced the results of a recent challenge designed to push the boundaries of payload weights a drone can carry based on its size, with the winner coming close to the agency’s goal of a four-to-one payload-to-weight ratio. AVIDrone’s winning design demonstrated a 3.84-to-1 payload-to-weight ratio, earning the Canada-based-based drone company a $1.25 million check. AVIDrone also has a U.S. office in Columbia, Md. The company's drone was a single-rotor helicopter design…