Closed-form approach to design distributed matching networks for high-frequency amplifiers

Based on the use of distributed lossless elements, a closed-form synthesis for double-frequency-matching networks is introduced with an emphasis on the design of high-frequency amplifiers. Three different circuit conditions are considered and design relationships are provided and discussed. Finally, the proposed approach, which uses the circle method, is successfully employed to design a Ka-band (26-32 GHz) linear amplifier with gain equal to 8 dB and return loss greater than 10 dB for the considered band. (C) 2006 Wiley Periodicals, Inc.