Answer :
The AM transmitter with a carrier frequency of 27 MHz modulated by a 2-kHz audio signal will produce side frequencies at 27.002 MHz and 26.998 MHz, with varying voltages and power levels at different modulation levels.
An AM transmitter operating at 27 MHz is subject to amplitude modulation by a 2-kHz audio signal. At varying modulation levels from 20% to 90%, we calculate the impact on the transmitted signal.
Component Frequencies in the AM signal:
The component frequencies in the AM signal include the carrier frequency of 27 MHz and two sidebands. The sidebands are created on either side of the carrier frequency at intervals equal to the modulating frequency. At 27 MHz with a 2 kHz modulation, the sidebands would be at 27.002 MHz and 26.998 MHz.
Maximum and Minimum Waveform Voltage:
The amplitude of the signal varies with different levels of modulation. For 20% modulation, the peak voltage across the 50-ohm load ranges from 25.3 to 37.9 V. For 90% modulation, it ranges from 3.14 to 60.1 V peak.
Sideband Signal Voltage and Power:
The voltage of the sideband signals and their corresponding power also change with the modulation level. At 20% modulation, the sideband voltage is 2.24 V with power of 0.1 W. At 90% modulation, we see a sideband voltage of 10.06 V and power of 2.025 W.
Load Current at 20% and 90% Modulation:
The load current through the 50-ohm resistor at 20% modulation is 0.451A, and at 90% modulation, it increases to 0.530A.
