Patent ID: 8073392

Claim:
A radio transmitter for transmitting a modulated signal comprising: a radio carrier source that generates a radio carrier signal, the radio carrier source powered by an electrical power source; and an antenna including at least one driven element and at least one reflector element, the driven element electrically coupled to the radio carrier source, at least one of the driven elements or said at least one reflector element including at least one switch, wherein the radio transmitter is configured to transmit a signal having a first modulation state in response to an open state of said at least one switch and is configured to transmit a signal having a second modulation state in response to a closed state of said at least one switch; said transmitter configured to transmit said signal in a solid angle within which information is transmitted with an error rate low enough to allow demodulation to recover a baseband signal, and outside of which solid angle sufficient power is transmitted but said information is transmitted with an error rate that is not low enough to allow demodulation to recover said baseband signal.