When isolation requirements are not high, it is also done with electronic switches. Some high isolation switches available in the market are very expensive. Two versions, absorptive and reflective have been introduced. This paper will describe these DC-5 GHz high isolation switches and a typical application. Performance Signal routing and automated testing are two major applications of switches.
Mechanical switches have high isolation and low-insertion loss.
However, they have very long switching time and limited life. Solid state switches using GaAs FETs overcome these problems and are extremely popular in switching applications. They have many advantages such as small size, extremely fast switching, low cost and long life. When these switches are integrated with TTL drivers, they can be easily driven with other logic circuits or with a personal computer having TTL driver cards. The main disadvantage of the GaAs switch is the moderate isolation.