RF Amplifier: Selection of Transistor

Discussion in 'Wireless & RF Design' started by rebelde, Feb 28, 2010.

  1. rebelde

    Thread Starter New Member

    Feb 28, 2010
    I'm a relative newbie to RF-design, especially when it comes to amplifiers.

    Now I need to design an amplifier for the 900MHz range. Goal is to build a linear amplifier which adds about 7dB gain to a 18dBm input signal. I thought by building up a transistor circuit I'll probably learn more than by taking some MiniCircuits MMIC from off the shelf - though I have some probs to find the right transtor for this task. All I know is the 2N2222, which I guess is not the right choice with a gain/bandwidth product of just 300MHz.

    I found e.g. a BFG21W, what about that one?
    Or are there any other / better transistors fur such an amplifier?

  2. bertus


    Apr 5, 2008

    Here is a list of RF transistors:

    Code ( (Unknown Language)):
    2. BFG11       Po=0.5W @ 1.9 GHz werkt al vanaf 3.6V                          11.34
    3. BFG32       (TO50-X case) zie BFT95
    4. BFG34       zie BFG135A (andere case)
    5. BFG35       idem smd, zie BFG135
    6. BFG65-3     Ft=8 GHz 3-pin                                                  1.82
    7. BFG67       Ft=8GHz SOT143                                                  2.90
    8. BFG90A      obsolete, zie BFG91a
    9. BFG91A      UHF/SHF TO50                                                    5.67
    10. BFG92A      zie BFG93A
    11. BFG93A      VHF/UHF/SHF SOT143                                              3.90
    12. BFG96       zie NE85635
    13. BFG97       Ft=5 GHz SOT223 npn                                             2.68
    14. BFG135      Ft=7 GHz SMD SOT223 (met koelvin)                               2.95
    15. BFG195      Extra low noise UHF                                             5.86
    16. BFG196      =BFG198 Ft=7.5 GHz I=max.100mA Ptot=0.75W/1W Populair in balans
    17.             13cm of parallel. SOT223                                        6.58
    18. BFG541      Breedband SOT223 20V-120mA-Ptot=0,65W Ft=9 GHz NF=1.3dB@900 MHz 4.90
    19. BFG591      Breedband SOT223 20V-200mA-Ptot=2,00W FT=7 GHz Gp=13dB          5.90
    20. BFP193      =BFP183 Ft=8 GHz SOT143 c-E-B-E                                 4.90
    21. BFP196      Ft=8.5 GHz smd SOT143 C-E-B-E vervangt vele Philips en
    22.             Siemens typen. B.v. als driver voor BFG196                      4.90
    23. BFP405      Ft=20 GHz speciaal voor X-band (10GHz) DRO osc. (toepassings-
    24.             schema aanwezig)                                                5.67
    25. BFP420      Ft=25 GHz SOT343                                                5.90
    26. BFP450      Ft=15 GHz SOT343 Max.100mA                                      6.13
    27. BFQ19S      FT=5 GHz SOT89 (smd-met-vin) Pt=1W                              3.86
    28. BFQ24       pnp Ft=5 GHz                                                    5.40
    29. BFQ34       Final UHF 2.5W see also MRF587                                 18.90
    30. BFQ43       zie SD1127
    31. BFQ65       =BFG65 in 3-pin X-case     zie BFG65
    32. BFQ68       UHF 5 W (high power BFQ34) Output 1.5W @ 13cm                  39.90
    33. BFQ69       Ft=5.5 GHz 15 mA                                                2.95
    The numbers at the end are the prices in euro's in holland.

    BFQ234 Hi-voltage 300mA SOT172 Ft=1GHz 4.