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

Coupling question between two amplifier stages

Status
Not open for further replies.
ahmad_abdulghany

ahmad_abdulghany

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
Hello all,
I have a small question,
What is the optimum coupling method between two transistor stages at 100MHz?
Capacitive coupling? Or Transformer?
If the latter, how to implement it? and calculate turns ratio?

Thanks in advance,
Ahmad,
 

It all depends on type of amplifier. Power RF amplifier needs matching between the stages. It can be done by LP filter or transformer, for example. If it is small signal amlifier then the coupling can be RC or DC.
 
sometimes in samll singal amplifiers like LNA u need a matching circuit
but the coupling capacitor shouldnot affect the coupling coz the coupling capacitor should be RF short circuit , but u need a capacitors to match the two stages

so u need both coupling capacitor and a matching circuit for max power gain

khouly
 
i think yeah , u need matching network between the two satges

khouly
 
ahmad_abdulghany,

Is your design broad-band or narrow-band? Do you use resistive or inductive collector/drain loading? Is it an LNA or PA or buffer?

I guess there is no good general answer to your question "What is the optimum coupling method between two transistor stages at 100MHz?". It will depend on many things.

/Peter
 
Is your design broad-band or narrow-band?
Click to expand...
I don't know what to say about it, it's in the range from broad cast FM, may be considered wide band, but mainly, i do care only in the range around 100MHz (say 95M to 105MHz)...

Do you use resistive or inductive collector/drain loading?
Click to expand...
What will be the differece? anyway, it's for now resistive...

Is it an LNA or PA or buffer?
Click to expand...
It's an LNA

Thanks for help,
Ahmad,
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top