A5 Receiver Assembly - Agilent Technologies 8711C Service Manual

A5 Receiver Assembly

Besides the above mentioned coupler change, there is little functional di erence between the
HP 8711C/12C/30A receiver and the HP 8713C/14C receiver assemblies. he most signi cant
di erences are listed below:
An RF limiter is installed to protect the source from excessive power and ESD.
he coupler is now an external microcircuit with a 16 dB coupling factor.
Some of the lters have di erent cuto /bandpass frequencies.
Some attenuators have di erent values.
A leveling loop is used to maintain proper LO power to the 3 mixers. his eliminates the
need for the LO power adjustment (adjustment #101).
Of course, all input components have been modi ed to perform at 3 GHz, but from a functional
point of view, little else is changed from the HP 8711C/12C/30A receiver board. Refer to the
block diagrams in Chapter 4.
6-8 Theory of Operat on