Patches of approximately 8square inches, with high power, bright. Toggle switch for pattern of blinking. Compact battery, rectifier, antenna coil packed into sealed fabric.
Powered by airwaves, charged by airwaves.
Power via radiowaves will be generated by a portable battery that is carried in backpack or placed in the area of activity, or placed with a companion robot that follows athelte around carrying personal belongings.
Sophisticated, but simplistic design of radiowave elements is the key for this technology. High amplitude and low frequency radio wave generation should out perform high frequency. Patches may procure capacitive distribution from host to achieve resonance of low frequency from transmitter and retain small scale components.(If that is possible, which it should be).
Also another form of this technology could be extensions for all usb powered devices to become powered by radio waves. Transmitter could plug into home outlet. And receiver could be pluged into any usb powered port.