Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

LNA design at 100MHz!!!!!!

Status
Not open for further replies.
ahmad_abdulghany

ahmad_abdulghany

Advanced Member level 4
Advanced Member level 4
Joined
Apr 12, 2005
Messages
1,206
Helped
102
Reputation
206
Reaction score
22
Trophy points
1,318
Location
San Jose, California, USA
Activity points
11,769
bfp405 lna

Hello,

I want a tutorial about the design of BJT LNA, i want to build it with discrete components at freq. ~ 100MHz,

I may use 2N2222 or 2N3904, or anyother suggested BJT..

Thanks for help,
Ahmad,
 

100mhz lna

I am not quite sure, but I think the design will not be different from an integrated counterpart. Most probably, you will use the degenerated common source configuration ( very popular/ low noise ). I think the book "Radio frequency Integrated circuits" by John Rogers can help. Send me a PM if you need it.
 
Use BFW series bipolar transistors of Philips that introduce very low noise at that frequency.
Neither 2222 or 3904 is not RF transistors.Those transistros can be unstable at some frequency with certain configurations..
 
i have used 3904 to do RF amp in 100MHz range it gave about 14.5 db power gain
but it took alot of tuning

khouly
 
Hello all

I found recently the 2SC3355 low noise transistor (vendor is NEC) , and used it to build a 39dB gain LNA with NF≈ 0.9 at 100MHz ...

Thanks to Khouly who guided me through ADS noise matching via Smith Chart tool :)

Thank you all for help,
Ahmad,
 

i would say..BFP405, BFP520 and BFG403W would be a good choice for your design...especially BFG403W is a good choice...using smith chart (plotting gain and noise circle)...you can get very good result. I have used it for discrete LNA design, and have to admit it was a very good performance..so try it (BFG403W)
 
Yeah, 2sc2255 is a good choice. I have used it many times. There are also many vendors producing this transistor.
 

BigBoss said:
Use BFW series bipolar transistors of Philips that introduce very low noise at that frequency.
Neither 2222 or 3904 is not RF transistors.Those transistros can be unstable at some frequency with certain configurations..
Click to expand...
How to select the transistor if I want to design 2.4GHz LNA,any design guide?
Thank you in advance.
 

also u can use BFG425W it is very good

and there are alot off applications notes
check this
**broken link removed**

also try avagotech "agilent"
HEMT atf35143

khouly
 
Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top