Question

8. What two circuits are used to generate the IF? (Intermediate Frequency)

62. The synthesizer in a transceiver usually generates what
frequencies?

Answer 1

8. The two circuits used to generate intermediate frequency (IF):

i) Local Oscillator

Generates a frequency f_LO for mixing with the incoming radio frequency f_IN.

ii) Mixer stage

Mixes through the process of heterodyning. the input radio frequency f_IN with the frequency f_LO from the local oscillator, to generate the intermidiate frequency f_IF = | f_IN - f_LO |

9. The synthesizer in a transceiver generates the frequency known as local oscillator (LO) frequency f_LO with very high accuracy and precision from a single reference frequency. This frequency can be used to downconvert incoming ignal to lower frequency to extract information or to upconvert message signal to radio frequency before transmission over medium. The synthesizer output signal is a sinusoidal tone plus megligible presence of harmonics added due to non-linearities. The synthesizer system is designed to ensure the accuracy of its output frequency under any condition.