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About OFDM PA
Posted: Tue Mar 31, 2015 4:59 am
by scsi
I want to design a PA for my OFDM at 433MHZ. The P1db shouldbe 2W,could you help to recommend a chip for this?Thanks
Re: About OFDM PA
Posted: Thu Apr 02, 2015 2:48 am
by MN-tech
The RA07H4047M module should do very well. It's nominal 7 watt device but the peak to average power ratio of OFDM may need the overhead to prevent spectral growth. The gain is about 35 dB at 2 watts.
http://www.rfparts.com/ra07h4047m.html
Re: About OFDM PA
Posted: Fri Apr 03, 2015 12:04 am
by oe7dbh
Hi
So let's be honest.
Even if you have an OFDM transmitter with -70dB Signal shoulder, and you want have a minimum of -40 dB signal shoulder Output with almost constant MER ..... then you get no more than:
800mW OFDM Signal with RA07H4047
5,0 Watt OFDM Signal with RA30H4047
9,0 Watt OFDM Signal with RA60H4047
http://www.oe7forum.at/viewtopic.php?f= ... =225#p1488
http://www.oe7forum.at/viewtopic.php?f= ... =180#p1394
http://www.oe7forum.at/viewtopic.php?f= ... =120#p1299
http://www.oe7forum.at/viewtopic.php?f=15&t=448
vy 73 Darko OE7DBH
Re: About OFDM PA
Posted: Fri Apr 03, 2015 11:06 pm
by g4wvu
DVB-T seems pretty bad news as far as generating sensible (DX) type power output is concerned. (Typical back-off 8-10dB !)
Makes DVB-S look very forgiving by comparisom....