Method and system for multi-channel RF digitization with analog selectivity
View Patent ↗A system ( 10 ) and method ( 100 ) for digitizing a complete band of RF channels to allow simultaneous processing of more than one channel. Multiple tunable bandpass filters ( 14 ) are used for the particular channels to be processed. The filter outputs are combined ( 16 ) to form one signal for digitization ( 18 ). In another embodiment, an undesired signal is rejected ( 112 ) to provide more available power for a reception of a desired signal.
1. A receiver for simultaneously processing multiple channels in a broadcast band, said receiver comprising:
at least one antenna for receiving analog RF signals;
a plurality of tunable bandpass filters, each tunable bandpass filter for filtering said analog RF signals, each tunable bandpass filter for tuning to a desired frequency signal, thereby defining multiple desired signals;
a summer for summing said multiple desired signals into one summed signal;
a digitizer for digitizing said summed signal; and
a digital tuner capable of simultaneously processing only the multiple desired signals from said digitized signal.
2. The receiver of claim 1 wherein at least two tunable bandpass filters are tuned to the same desired frequency and combine to draw maximum power for reception of said desired frequency.
3. The receiver of claim 1 wherein at least one tunable bandpass filter in said plurality of tunable bandpass filters is tuned to a first desired frequency and another of said tunable bandpass filters in said plurality of tunable bandpass filters is tuned to a second desired frequency for simultaneous reception of at least two different desired frequencies.
4. The receiver of claim 1 further comprising an automatic gain controller and an amplifier at the respective output of each of said plurality of bandpass filters.
5. The receiver as claimed in claim 4 further comprising at least one tunable bandpass filter in said plurality of bandpass filters being tuned to a first desired frequency and another of said tunable bandpass filters in said plurality of said tunable bandpass filters being tuned to a second undesired frequency; and
wherein said automatic gain controller and amplifier at said output of said tunable bandpass filters that is tuned to said undesired frequency is set at a minimum gain for absorbing said undesired frequency and providing additional receiving power for said first desired frequency.
6. A method for reception of multiple channels on a single broadcast band, said method comprising the steps of;
receiving a multi-frequency analog RF signal;
filtering said multi-frequency analog RF signal into a predetermined number of desired analog frequencies;
combining only said predetermined number of desired analog frequencies into a single combined analog signal;
digitizing said single combined analog signal into a digitized combined signal;
simultaneously selecting a plurality of desired signals having different frequencies from a digital tuner that receives said digitized combined signal.
7. The method as claimed in claim 6 wherein said step of filtering further comprises filtering said multi-frequency analog RF signals into a predetermined number of desired analog frequencies through a plurality of independently tunable bandpass filters.
8. A method for rejecting an undesired frequency signal in a single broadcast band while improving reception of a desired frequency signal in the broadcast band, said method comprising the steps of:
receiving a desired signal from the broadcast band;
filtering said desired signal through a first tunable bandpass filter;
receiving a predetermined undesired signal from the broadcast band;
filtering said predetermined undesired signal through a second tunable bandpass filter;
adjusting an automatic gain control for said second tunable bandpass filter to a minimum gain thereby absorbing said predetermined undesired signal; and
digitizing said desired signal.