Analog Electronics

What is Analog Electronics??
Analog electronics (or analogue in British English) are those electronic systems with a continuously variable signal.The term "analogue" describes the proportional relationship between a signal and a voltage or current that represented the signal. (en.wikipedia.org)

Historically, analog electronics was used in large part because of the ease with which circuits could be implemented with analog devices. However, as signals have become more complex, and the ability to fabricate extremely complex digital circuits has increased, the disadvantages of analog electronics have increased in importance, while the importance of simplicity has declined.

In analog electronics, the signals to be manipulated take the form of continuous currents or voltages. The information in the signal is carried by the value of the current or voltage at a particular time t. Some examples of analog electronic signals are amplitude-modulated (AM) and frequency-modulated (FM) radio broadcast signals, thermocouple temperature data signals, and standard audio cassette recording signals. In each of these cases, analog electronic devices and circuits can be used to render the signals intelligible.

Commonly required manipulations include amplification, rectification, and conversion to a nonelectronic signal. Amplification is required when the strength of a signal of interest is not sufficient to perform the task that the signal is required to do. However, the amplification process suffers from the two primary disadvantages of analog electronics: (1) susceptibility to replication errors due to nonlinearities in the amplification process and (2) susceptibility to signal degradation due to the addition, during the amplification process, of noise originating from the analog devices composing the amplifier. These two disadvantages compete with the primary advantage of analog electronics, the ease of implementing any desired electronic signal manipulation.