[time-nuts] DIY Frequency extension for HP Agilent

Grant Hodgson grant at ghengineering.co.uk
Mon Feb 16 12:54:27 UTC 2009


The NLB-300 and NBB-300 series MMICs from RFMD work very at up to 13GHz 
or so, certainly far better than a Mini-circuits ERA- whose gain will 
start to roll off at higher frequencies.  Designing a broadband gain 
stage to work up to 12GHz+ may not be as easy as it seems.  However it 
is made somewhat easier by the use of broadband chokes from the likes of 
Mini-Circuits, wideband inductors from Coilcraft and broadband 
capacitors from ATC - to name but three - there may be others as well.

The 4-stage amplifier used by HP not only increases the signal level, it 
increases the slew rate (V/uSec) at lower frequencies.  It's not just 
about signal level, it's about getting fast edges.  The Hittite HMC363 
/8 is a great IC, using static flip-flops, and will work all the way 
down to DC - IF the edges are fast enough.  Ironically it may be the 
case that the lower frequency limit presents more of a challenge than 
the higher frequency limit.



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