4.2-5 You are asked to design a DSB-SC modulator to generate a modulated signal Acm(t) cos wet with the carrier frequency fc = 300 kHz (wc = 2π x 300,000). The following equipment is available in the stockroom: (i) a sinewave generator of frequency 100 kHz; (ii) a ring modulator; (iii) a bandpass filter with adjustable center frequency with the tuning range of 100 kHz to 500 kHz. (a) Show how you can generate the desired signal. (b) Explain how to tune the bandpass filter. (c) If the output of the modulator must be 400 m(t) cos wet, what should be the amplifier gain to be used on the input m(t) to obtain the desired modulator output signal amplitude?