Patent ID: 6842497

Claim:
In a data filtering apparatus for a multiplexing unit wherein a radio frequency signal is input to a device that converts said radio frequency signal to a plurality of data signals correlated with the frequencies of the radio frequency signal, and that are detected by a photodiode array, the detected plurality of data signals are output from the photodiode array on a path that inputs the plurality of data signals to the multiplexing unit for processing the improvement comprising: a) a processing unit, arranged in parallel with the path from the photodiode array to the input to the multiplexing unit, to process the plurality of data signals detected by the photodiode array, b) the processing unit, processing the plurality of data signals to identify at least one data signal conforming to a predetermined criteria, c) the processing unit including a digital logic unit to generate and transmit, an identifying and selective processing signal in response to the identification of the at least one data signal conforming to the predetermined criteria, to the multiplexing unit for controlling the identification and selective processing of the at least one data signal conforming to the predetermined criteria from among the plurality of data input signals being input to the multiplexing unit on the path from the photodiode array to the exclusion of the remaining plurality of data signals not conforming to the predetermined criteria being input to the multiplexing unit on the path from the photodiode array, and d) the processing unit being coupled to the multiplexing unit via an output data bus to transmit the identifying and selective processing signal in response to the identification of the at least one data signal conforming to the predetermined criteria to the multiplexing unit for identification and selective processing of the at least one data signal conforming to the predetermined criteria, e) whereupon the multiplexing unit selectively processes the identified at least one data signal conforming to the predetermined criteria from among the plurality of input data signals being input to the multiplexing unit on the path from the photodiode array to the exclusion of the remaining plurality of data signals not conforming to the predetermined criteria being input to the multiplexing unit from the photodiode array.