Title :
Design and characterization of a microwave feed-forward amplifier with improved wide-band distortion cancellation
Author :
Hau, Y. K Gary ; Postoyalko, Vasil ; Richardson, John R.
Author_Institution :
Sch. of Electron. & Electr. Eng., Leeds Univ., UK
Abstract :
A new approach to the design of a wide-band feed-forward amplifier (FFAMP) is presented in this paper. Phase equalizers are employed in an FFAMP to match the nonlinear delay/phase characteristics of the main and error amplifiers, improving phase balances within the cancellation loops and providing improvement in signal cancellations over a wide bandwidth. The proposed 1.7-1.9-GHz FFAMP was fabricated and characterized. The conventional FFAMP obtains an average of 15-dB third-order intermodulation (IM3) distortion cancellation over the whole bandwidth. With the phase equalizers, the proposed FFAMP achieves a further 6-dB reduction on IM3 level.
Keywords :
UHF amplifiers; equalisers; feedforward; intermodulation distortion; linearisation techniques; microwave amplifiers; wideband amplifiers; 1.7 to 1.9 GHz; IM3 cancellation; amplifier characterization; cancellation loops; error amplifier; intermodulation distortion cancellation; linear amplifiers; main amplifier; microwave feedforward amplifier; nonlinear delay/phase characteristics matching; phase balances; phase equalizer design; third-order IMD cancellation; wideband distortion cancellation; Bandwidth; Broadband amplifiers; Circuits; Delay; Equalizers; Feedforward systems; Frequency; Microwave amplifiers; Nonlinear distortion; Phase distortion;
Journal_Title :
Microwave Theory and Techniques, IEEE Transactions on
