Design of an ultrawide band low noise microstrip amplifier using 3D sonnet- based SVRM with particle swarm optimization for space applications

In this work, a determinististic, efficient design methodology is put forward to design a wide-band, low-noise microstrip amplifier, where the microstrip widths, lengths {W^→,ℓ^→} of the input/ output matching networks are obtained accurately and fast for a substrate {ε_r, h, tanδ} using the cost-effective 3D EM- based Support Vector Regression Machine (SVRM) microstrip model provided that ensuring the stable source Z_S(ω) and load Z_L(ω) terminations for the compatible {Noise F(ω) ≥ F_min(ω), Input VSWR Vi(ω) ≥1, Gain G_Tmin(ω)>G_T(ω)≥G_Tmax(ω), Bandwidth B} quadrates of the employed transistor. The 3D EM- based SVRM microstrip model provides the accurate and fast characterization of the equivalent transmission line in terms of the characteristic impedance Z₀ and the dielectric constant ε_eff within the continuous domain of {0.1mm ≤ W ≤ 4.6 mm, 2 ≤ ε_r ≤ 10, 0.1mm ≤ h ≤ 2.2mm, 2GHz ≤ f ≤ 14GHz} in an efficient manner. In the modeling process, the substantial reduction (up to %64) is obtained utilizing sparseness of SVRM in the number of expensive fine discretization training data with the negligible loss in the predictive accuracy using the quasi-TEM microstrip synthesis formulas as the coarse model that allow to identify the regions of the design space requiring denser sampling. Moreover, the multi-objective amplifier design problem is reduced into the two single-objective design problems of the input(IM)/ output (OM)matching networks to provide the source Z_S(ω) and load Z_L(ω) terminations to the transistor, respectively. Finally the design methodology is applied to the design of typical wideband lo- -noise amplifiers of the transistor NE3512S02 within 3GHz and 8GHz using T-, II- L types of microstrip matching circuits satisfying the maximum gain provided the available minimum noise and a permitted amount of input mismatching at each operation frequency. In the design optimization of the IM/OM networks, a Memetic Algorithm (MA) in which a simple local optimizer called Nelder-Mead (NM) algorithm is used along with the global optimizer Particle Swarm (PSO) algorithm is used. Furthermore, typical T-T designed amplifier is validated using the Circuit Simulator AWR and 3 D EM Simulator SONNET.