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

Transistor for FM 88-108 MHz 1-4 W PA

Status
Not open for further replies.
boy

boy

Advanced Member level 1
Joined
Sep 30, 2002
Messages
481
Helped
98
Reputation
196
Reaction score
58
Trophy points
1,308
Location
Thailand
Activity points
3,963
mrf237

Any sugestion? I have tried 2N3866 and 2N4427 but i did not get close to 1 W.
 

pulsarfm.nl

boy said:
Any sugestion? I have tried 2N3866 and 2N4427 but i did not get close to 1 W.
Click to expand...

How much drive are you putting into it? The 2N3866 will easily produce > 1 watt provided you have the correct impedance matching and drive level min 0.1W
 
pulsarfm nl

Dear, E-design, that what my plan, 100mW drive. it could be few hundred miliwatts. Any technique to design the input matching?. now I use the load pull in ADS to get power ouput about 1 watt with 6 dB gain. I plan to use LSSP to find the input matching network and get more gain. But I still can not tune the one that actualy build to get close to 1 watt. Still keep trying.
 

mrf237 fm rf amplifier

The easiest is if you have data from the manufacturer about the large signal s-parameters. I have found that the data can differ quite a lot between manufacturers. If you have a network analyzer, you could measure it yourself. I have not verified the ADS model for the 2N3866. I worked from some very old data from Motorola giving large signal s-param for the 2N3866 and designed my matching from there. Luckily I had some devices made by Motorola. If you want I can let you have a copy of the Motorola data in pdf if I can find on my PC
 

    boy

    boy

    Points: 2
    Helpful Answer Positive Rating
transistor mrf237

Thank you E-design, I have looked at the attatched datasheet and I have some questions. In the test circuit, it seems that they use common collector for DC bias and common emitter for RF. do u know why? (It crearifies me why the whole metal case of the transister is a collector terminal :) )About the large signal S-parameter, I do have a network analyszer (Anritsu), the problem is it can deliver only 7 dBm maximum at the port but I need at least 20 dBm to drive the amplifier. Any technique to do that?? Can I just put a driver amplifer and calibrate the network analyzer at the output port if the driver amplifier?
 

transistor de fm

hello.gif
BOY

Have you try to use MRF237 ???

**broken link removed**

http://homepage.eircom.net/~yellowbeard/mrf237.htm

http://www.cbsite.nl/modif/3meter/mrf237/mrf237.htm
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top