This paper examines the simulation of a Low Noise Amplifier with lumped components in output and intermediate matching networks in frequency range of 3-5.1 GHz. The paper shows that due to unavailability of exact values of ideal lumped components in form of vendor components designed LNA parameters will change accordingly due behavioral change in values of components. Small change in values of components causes large changes in S-parameters of device which will cause respective change in parameters since all parameters are related with S-parameters at microwave regions. This proposed Low Noise Amplifier has been designed and simulated in AWR Microwave Office. The designed amplifier provides noise figure <1.5 dB, gain >23 dB, Input Return Loss < -10 dB and Output Return Loss <-10.4 dB with unconditional stability in frequency range of 3 – 5.1 GHz with both ideal lumped component design and vendor lumped component.