(a) A shunt-feedback amplifier is shown in Fig. 11.55. Using equivalent input noise generators for the device, calculate the spot noise figure of this circuit in decibels for R_S= 10 kΩ using the following data. I_C= 0.5 mA β = 50 r_b= 100 Ω Neglect flicker noise and capacitive effects.

(b) If the device has f_T = 500 MHz, calculate the frequency where the noise figure is 3 dB above its low-frequency value.

Fig. 11.55:

 

Transcribed Image Text:

10 k2 Vo 10 k2 Rs