Method and system for transmitting signals with reduced spurious emissions

Abstract

An RF power amplifier architecture minimizes spurious emissions by breaking the transmitted signal into narrow spectrum sub-bands, amplifying each separately, and then combining the signals for transmission purposes.

1 . A system comprising:
 a plurality of digital-to-analog (D/A) converters, each of the plurality of DI A converters configured to receive one of a plurality of sub-bands of an input signal;   a plurality of amplifiers, each of the plurality of amplifiers in signal communication with one of the plurality of D/A converters and configured to receive a signal generated by the one D/A converter of the plurality of D/A converters with which the amplifier is in signal communication;   a combiner in signal communication with each of the plurality of amplifiers, the combiner configured to vary the amplitude and phase of a plurality of signals and to combine the plurality of signals into a single signal, each of the plurality of signals being received from one of the amplifiers; and   a first antenna in signal communication with the combiner, the antenna configured to receive the single signal generated by the combiner and to transmit the single signal over the air.   
     
     
         2 . A system as recited in  claim 1 , further comprising:
 a second antenna remote from and physically disconnected from the first antenna, the second antenna configured to receive the signal transmitted over the air by the first antenna.   
     
     
         3 . A system as recited in  claim 1 , wherein each sub-band of the plurality of sub-bands contains a different spectral component of the input signal. 
     
     
         4 . A system as recited in  claim 1 , further comprising:
 a calibration unit configured to calibrate amplitude and phase differences for the plurality of sub-bands.   
     
     
         5 . A system as recited in  claim 1 , further comprising:
 a plurality of up-converters, each up-converter configured to receive output from one of the plurality of D/A converters and to provide input to the one of the plurality of amplifiers in signal communication with the one of the plurality of D/A converters.   
     
     
         6 . A system as recited in  claim 1 , further comprising:
 a modem in signal communication with each of the plurality of D/A converters, the modem configured to convert the input signal into a plurality of sub-band signals, each of the plurality of sub-band signals containing one of the plurality of sub-bands.   
     
     
         7 . A system as recited in  claim 1 , wherein the combiner is configured to iteratively vary the amplitude and phase of the plurality of signals until a desired single signal output is obtained. 
     
     
         8 . A system as recited in  claim 7 , wherein the desired single signal output is a minimum. 
     
     
         9 . A system as recited in  claim 7 , wherein the combiner is configured to iteratively vary the amplitude and phase of the plurality of signals over a plurality of input signals, each of the plurality of input signals obtained from a separate channel. 
     
     
         10 . A system as recited in  claim 1 , wherein the combiner is configured to apply a phase change to each of the plurality of signals.