MMIC amps: Input impedance

[Joerg]

My observation is that if you want a NF below 3 dB, from a 50 ohm
signal, you've gotta tune the input. Some of the NEC phemts get below
1 dB, since the Cin is very low and the matching network can give a
bunch of free voltage gain.

I found that common gate or common emitter stages are really useful when
pushing the noise figure on wideband amps. That's also how it is done in
modern shortwave communication gear where frequency agility all but
prohibits the use of tuned circuits.

I just had a burger with Mo at the Zuni Cafe, and I'd be astonished if
any mere mortal can make their own burger that good. They serve it on
fresh focaccia with homemade pickles and pickled onions and homemade
aioli. $12.

Certainly. Restaurants can serve excellent burgers. Our favorite is
Hangtown Brewpub in Placerville and you can get fabulous garlic fries
and a fresh stout or ale with it. Around $8, plus the brew.

What I meant was barbequeing at home. The vast majority merely slaps
some pre-pressed patties on the grill and that's what we never do. It is
always from scratch.

 

[John Larkin]

I found that common gate or common emitter stages are really useful when
pushing the noise figure on wideband amps. That's also how it is done in
modern shortwave communication gear where frequency agility all but
prohibits the use of tuned circuits.

What sort of wideband nf's are possible? Shortwave doesn't really need
a good nf, does it?

Certainly. Restaurants can serve excellent burgers. Our favorite is
Hangtown Brewpub in Placerville and you can get fabulous garlic fries
and a fresh stout or ale with it. Around $8, plus the brew.

What I meant was barbequeing at home. The vast majority merely slaps
some pre-pressed patties on the grill and that's what we never do. It is
always from scratch.

Sure. Ground sirloin from not-Safeway.

John

 

[Joerg]

What sort of wideband nf's are possible? Shortwave doesn't really need
a good nf, does it?

Don't remember but we came really close to the advertised noise figures
of the transistors. It was ultrasound, same range as shortwave but noise
really matters there.

Most pathetic was that we were told back at the alma mater that using a
FET in common gate is the stupidest thing an RF engineer can do. Of
course I did not believe that. Actually I was sitting at the front of
the auditorium and to the dismay of the prof I burst into laughter.
Couldn't help it because I had just built one for my ham radio station.
Then my very first project after getting my degree was, guess what?

Sure. Ground sirloin from not-Safeway.

The trick is in the spices and dashes of this or that marinade in there.
At the end of prep my wife crunches Pringles chips (the spicy ones) by
placing them in a bag and running the pin roller over it until
pulverized. Then that goes into the meat.

The way be cook them in the barbie they become more round than normal
burgers. They also keep really well in the freezer. Problem is, the
freezer is in my LAN closet and it's tough to pass by if I know there
are some burgers in there.