Electronic signals are used by almost all measurement and control systems to transfer information. Much of this data is in the form of analogue voltages, which are prone to the effects of noise and interference.

Interference is picked up from external sources present in the local environment. These sources are usually beyond the control of the systems engineer and so their effects must be moderated by careful earthing and shielding. Noise is generated within the circuits, and components themselves, and by good design may be reduced but not eliminated.

Answer the following questions.

1 Convert the following gains to dB.

a) power 3, 17, 854

b) voltage 5, 28, 36500

2 Convert the following gains to arithmetic ones

a. power 3 dB , 45 dB , 126 dB

b. voltage 2 dB , 35 dB , 126 dB

3 Express the following powers in dBm:

15 mW, 165mW, 10 µW