DESIGN OF AN ULTRA-WIDEBAND, LOW-NOISE AMPLIFIER USING A SINGLE TRANSISTOR: A TYPICAL APPLICATION EXAMPLE

Abstract

In this work, a design method of an Ultra-Wideband (UWB), low-noise amplifler (LNA) is proposed exerting the perfor- mance limitations of a single high-quality discrete transistor. For this purpose, the compatible (Noise F, Input VSWR Vi, Gain GT) triplets and their (ZS, ZL) terminations of a microwave transistor are exploited for the feasible design target space with the minimum noise Fmin(f), maximum gain GT max(f) and a low input VSWR Vi over the available bandwidth B. This multi-objective design procedure is reduced into syntheses of the Darlington equivalences of the ZSopt(f), ZLmax(f) terminations with the Unit-elements and short-circuited stubs in the T-, L-, ƒ-conflgurations and Particle Swarm Intelligence is successfully implemented as a comparatively simple and e-cient optimization tool into both veriflcation of the design target space and the design process of the input and output matching circuits. A typical design exam- ple is given with its challenging performance in the simple ƒ- and ƒ-conflgurations realizable by the microstrip line technology. Further- more the performances of the synthesized ampliflers are compared us- ing an analysis programme in MATLAB code and a microwave system simulator and verifled to agree with each other.