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

[boy]

mrf237

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

 

[IanP]

mrf237 impedance matching

Here are some other options:

https://www.pcs-electronics.com/schematics/RF Power Transistor.htm

Regards,
IanP

 

[E-design]

pulsarfm.nl

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

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

 

[boy]

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.

 

[E-design]

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]

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?

 

[fbg]

transistor de fm

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