LR <lrme@privacy.net> hath wroth:

>Jeff Liebermann wrote:
>> miso@sushi.com hath wroth:
>>
>>> The whole intent of SiGe was heavy integration. I don't think there is
>>> enough money in SiGe stand alone amp chips, or perhaps better stated
>>> the money is in the system on a chip.
>>
>> Probably true for individual transistors, but there's quite a bit of
>> SiGe in use in the form of simple downconverters and RF front ends.
>> For example:
>> <http://www.maxim-ic.com/quick_view2.cfm/qv_pk/1918>
>> <http://para.maxim-ic.com/results.mvp?q=lna&an_1=Family&av_1=Low-Noise%20Amplifiers>
>> Most are in the 1.5 to 3.0dB NF range, which is nowhere near the 0.4dB
>> NF that can be achieved with a properly optimized discrete GaAs FET
>> design.

>Was reading about these last week. BFU725F's
>http://www.spoerle.com/download/en_1...NXP_BFU725.pdf

Yep. Much easier to bias and protect SiGe xsistors than to deal with
the tangled mess required for GaAs FET's. 0.4dB NF and 26dB gain at
1.8GHz is very close to what a commodity GaAS FET will do. Thanks for
the pointer. That's the first I've heard of SiGeC.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558