Showing posts from March, 2022

24GHz LNA design

So, here are my thoughts on an LNA design for 24 GHz, inpired by Ron Schiltmans DU3T design, I thought I would try something similar. The basic concept is a waveguide input, 2 stage desgin for 24GHz,  with a CE3520K3 FET on the input, and a MMIC amplifier as the second stage.  For the second stage I plan to use an HMC341 I will include my calculations and assumptions for the design, if you can spot an error in my thoughts, I would be of course, delighted to hear from you! The circuitry on the left is a simple 3.3V regulator, feeding a ICL7660 negative voltage generator. The 3.3V is used to feed power to the MMIC amplifier and the input FET.  A simple P type FET prevents power being supplied to the front end FET before the negative voltage is present.   The  CE3520K3 was selected as it is pretty much the only real option easily obtainable from Mouser. I'd like to give you a better answer based on cost and performance, selection of matching parameters etc, but basically, it comes dow

Dish update ... pretty much there.

 Finally completed the 3 little stainless steel "pucks" that form the locking arrangement for securing the dish "L Bracket" to the pan and tilt head's quick release mechanism.  Those innocuous little lumps of stainless where a pain to machine and adjust, Not something I would want to do again, although I suspect I will have to as I have 2 of these pan and tilt units!  I'll probably add some sort of trianglular brace, just to take some strain off the bolts, but, its pretty rigid as it stands. The basic sequence is tripos erected, L bracket clipped on to the pan and tilt unit. Dish hooks on to the front with the 4 prongs. Feed is inserted through the hole, big brass nut tightened up, job done.