ApplicationNo. 491829 filed on 07/25/1974
US Classes:342/42, RADAR TRANSPONDER SYSTEM375/277, Vestigial or single sideband, or suppressed carrier375/295, TRANSMITTERS455/193.1, With antenna circuit tuning455/44, With stated modulation index455/92Remote control of a transmitter
ExaminersPrimary: Griffin, Robert L.
Assistant: Bookbinder, Marc E.
Attorney, Agent or Firm
AbstractA data transmission system for obtaining information from a plurality of data sources includes an interrogate source for transmitting RF interrogate signals to the locations of the data sources and a transponder associated with each data source for receiving the interrogate signals and for generating RF reply signals representing the information. The transponder includes a transmitter having a voltage controlled oscillator responsive to data signals at first and second levels to generate sinusoidal output signals at first and second frequencies, respectively, a wave shaping circuit which converts the output signals to sawtooth wave signals at the corresponding frequencies and an FM oscillator for providing a carrier signal which is modulated by the sawtooth signals to produce a broad spectrum of sideband signals of approximately equal amplitude.