IMPLEMENTATION OF A TECHNIQUE TO AMPLIFY COMPLEX SIGNALS THROUGH NON-LINEAR AMPLIFIERS

IN MANY COMMERCIAL APPLICATIONS, COMPLEX SIGNALS SUCH AS MULTIPLE CARRIERS MUST UNDERGO POWER AMPLIFICATION WITHOUT DISTORTION. TYPICALLY, HIGH POWER AMPLIFIERS ARE VERY NON-LINEAR. CURRENT TECHNIQUES TO ADDRESS THIS PROBLEM ARE INEFFICIENT AND EXPENSIVE. MIXTEC SIGNAL TECHNOLOGY, (MST) HAS DEVELOPED AND APPLIED FOR A PATENT ON A TECHNIQUE WHICH CAN USE PURELY DIGITAL PRE-PROCESSING OF THE SIGNAL SUCH THAT OUTPUT AMPLIFIERS ARE ONLY REQUIRED TO AMPLIFY A SATURATED, PULSE MODULATED SIGNAL. THIS TYPE OF AMPLIFICATION CAN BE DONE VERY EFFICIENTLY BY POWER AMPLIFIERS SUCH AS CLASS C TRANSISTOR STAGES. MST'S TECHNIQUE RESULTS IN AN OUTPUT POWER SPECTRUM CONSISTING OF THE AMPLIFIED ORIGINAL SPECTRUM AND SIDEBANDS, FAR FROM THE CARRIER, WHICH ARE ELIMINATED BY AN OUTPUT BAND PASS FILTER. THIS APPROACH IS MORE EFFICIENT AND COST EFFECTIVE THAN CURRENT APPROACHES. THE LINEARITY OF THIS APPROACH IS DEPENDENT ON THE PERFORMANCE OF THE DIGITAL PRE-PROCESSING. INTEGRATION OF THE TECHNIQUE INTO A HIGH SPEED ASIC WOULD ALLOW THE DEVICE TO BE EFFECTIVE FOR A NUMBER OF COMMERCIAL APPLICATIONS SUCHAS CELLULAR TELEPHONE AND OTHER MOBILE RADIO APPLICATIONS. IN THE PROPOSED PROGRAM, A PROTOTYPE OF THE SYSTEM WILL BE CONSTRUCTED AND TESTED IN ORDER TO DEMONSTRATE THE POTENTIALFOR EXTREMELY LINEAR AMPLIFICATION. IN PARALLEL, A COMPUTERSIMULATION WILL DEMONSTRATE SUCCESSFUL OPERATION AT THE HIGHER CLOCK RATES REQUIRED FOR GREATER BANDWIDTH CAPABILITY.