Patent ID: 7482971
Filing Date: 2009-01-27
Classification: G01S

Abstract:
1. A time-of-flight ranging system comprising: an antenna for emitting an energy pulse and coupling a reflected energy pulse; a switch having a first terminal, a second terminal, a third terminal, and a control terminal, said control terminal adapted for receiving a control signal for switching said first terminal between said second terminal and said third terminal, and said second terminal being coupled to said antenna for selecting said antenna in response to said control signal; a controller having an output coupled to the control terminal of said switch, and a component for generating the control signal for controlling said switch; a transceiver operatively coupled to said controller having a bidirectional port coupled to the first terminal of said switch, said transceiver having an input port for receiving a pulse train and generating a transmit pulse for exciting said antenna for emitting said energy pulse, and said transceiver having an output port for outputting a reflected energy pulse received from said antenna; and a calibration module having a calibration bidirectional port coupled to the third terminal of said switch, said calibration bidirectional port being selectively coupled to the bidirectional port of said transceiver through said switch in response to said control signal, and when selectively coupled said calibration module receiving a calibration transmit pulse from said transceiver, and said calibration module including a calibration component for generating an echo pulse in response to said calibration transmit pulse; wherein said calibration transmit pulse is separated in time from said echo pulse by a calibration time of flight corresponding to an equivalent length of travel of the transmit pulse in air.