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Author Topic: 0.1-2000mhz rf wideband amplifier gain 30db low-noise amplifier lna board  (Read 270 times)

OD5ZZ

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  • Posts: 21

Hi

Can someone help with the how to build one of those boards please-schematic

0.1-2000mhz rf wideband amplifier gain 30db low-noise amplifier lna board

73's de Walid-OD5ZZ
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VK2TIL

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This is an application for an MMIC or, perhaps, two in cascade.

There are myriad schematics on-line, eg;

https://www.minicircuits.com/appdoc/AN60-010.html

They appear simple but some care is required to avoid instability with such high gain.

I built several such amplifiers in the early days of MMICs; I now buy kits or ready-made devices.

It's almost impossible to make a PCB yourself; performance depends on myriad vias that connect the upper and lower ground planes.  There are substitutes (I have used wires, brass tubes and copper rivets) but plated-through vias are far better.

I built this pair from kits supplied by MiniKits in VK;




The PCB is designed to take two MMICs (I used GALI-39s) but Mark at MiniKits said that no-one had been brave-enough to use two!

It took some shielding to stabilise the +40dB of gain;




I also wanted about 20dB of low-noise gain so I bought two ready-built amplifiers from ebay;




I modified them with better blocking capacitors and suitable bias resistors for 12v operation;




and added a panel and a cover for the DC connection;






This might give you some ideas.

Note that these amplifiers are used on the test bench; the gain is very high and I would be reluctant to connect either to an antenna & a receiver.

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VK6HP

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Walid,

Kerry beat me to some of the eBay references but if you really want to build a MMIC amplifier yourself you could try something like this one:

https://www.minikits.com.au/electronic-kits/rf-amplifiers/rf-low-noise/PGA-103-Amplifier

(The schematic will be the same, or similar, to that in the MMIC application note, linked via the support page).

73, Peter.
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