# Attenuators

Attenuators are used to damp a signal. Using pure ohmic resistors the circuit can be realized for a very high bandwidth, i.e. from DC to many GHz. The power attenuation is defined as:

 (14.1)

where and are the input and output power and and are the input and output voltages.

Fig. 14.1 shows an attenuator using the -topology. The conductances can be calculated as follows.

 (14.2) (14.3) (14.4)

where and are the input and output reference impedances, respectively. The -attenuator can be used for an impedance ratio of:

 (14.5)

Fig. 14.2 shows an attenuator using the T-topology. The resistances can be calculated as follows.

 (14.6) (14.7) (14.8) (14.9)

where is the attenuation ( ) according to equation 14.1 and and are the input and output reference impedance, respectively. The T-attenuator can be used for an impedance ratio of:

 (14.10)

This document was generated by Stefan Jahn on 2007-12-30 using latex2html.