So they're charging batteries from a 30 foot distance using an RF field at multiple gigahertz? What's to prevent interference with other devices in the same frequency band? Let's say the emitter emits one watt of RF -- it's probably higher, but just for the sake of argument. A typical Wi-Fi access point uses 50 milliwatts, or 1/20th the power of the charging transmitter. This means existing spectrum users would be overwhelmed by wide adoption of these devices.
Also, there are legitimate health concerns about being near a cell phone emitting 100 milliwatts of RF power. How can a device that emits ten times that power level, or more, be assumed to be safe near people?
> If they can deploy this device city wide, then we don't need any more chargers.
Yes, but we won't have any more wireless access points -- they'll be overwhelmed by higher-powered competitors.