It is desired to design a phase shift oscillator using an FET having a g_m = 5000 μSiemen, r_d = 40 kΩ and feedback circuit value of R = 10 K. Then value of C for oscillator operation at 1 kHz and that of R_D for A = 40 to ensure oscillator action are

For a FET oscillator, the oscillator frequency is ∴ C = 6.4 nF For FET Oscillator, |A| = g_mR_L = 5000 x 10^-6 R_L i.e., 40 = 5000 x 10^-6 x R_L ∴ = 8 KΩ Now, Using R_L = 8 K and r_d = 40 K (given) We find R_D as follows: ∴ ∴ = 10 K R_D = 10 K.