Re: Modamps

geoffrey pike

Hi Andy and group,
I used ERA-1 in a cascaded amp for 3cm and from my notes got 16dB gain but with limited output.
I then used the RFMD NLB-310 device that Farnell use to do.
P1dB +13 dBm and 9.6 dB gain.
I got mine from Australia i think RF-Kits?, not sure if they are still available and RFMD has merged i believe.
The ERA-1 devices are very cost effective and some rudimentary tabs on the lines helped somewhat.
I think there is a picture of the ERA-1 amp in the files section and some other stuff.

On Sunday, 12 June 2016, 10:34, "Andy Talbot andy.g4jnt@... [ukmicrowaves]" wrote:

Over the years I've watched Silicon modamps (the MAR series) morph into the GaAs ERA types, and seen a host of lower frequency very high gain and low noise figure types like the PGA and MGA  ones appear.   All influenced, no doubt, by the mobile market with its low GHz operations

But has much happened at the high frequency end, 8 to 12GHz? What more modern devices are suited up there?

This came about as I wanted a modest gain amp of about 7dB at 10GHz to boost the output of the mixer described in the latest Scatterpoint up to around -4dBm to drive a 1 Watt PA.   I had a couple of ERA-1 devices which, although only specified to 8GHz, have been reported as going to 10Ghz and even higher.

I used a bit of hacked-off old Amstrad board (remember those ?) placing the ERA where one of the old GaAs FETs would have gone, stripping off tuning stubs and adding a couple of 3.3pF ATC capacitors.   Ending up with the arrangement here : 

Result,  8dB of small signal gain at 10GHz, which is rather more than extrapolating the data sheet curve suggests. So plenty of margin in hand for my purpose.

But, what modamp type devices are recommended up here?  Surely the ERAs are a bit long-in-the-tooth now ?

Andy  G4JNT

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