User's Manual Part 1

Power Amplifier Module
The power amplifier module has a female SMA RF input connector on the front of the mod
ule. The RF I/P signal applied to this connector is amplified and transmitted from the back
of the module through a female N connector. There are several power configurations avail
able with or without feed forward linearization. Power level ratings vary depending on the
type of modulation used. In systems using QAM, power is rated in terms of average
power. In systems using analog video modulation power is rated in terms of peak synch
power. Typically, peak output power levels in systems using QAM can reach 4 times the
average power. For 64 and 256 QAM, this 6dB back-off is required to assure both a quasi
error free bit error rate with forward error correction and a spectral regrowth low enough to
prevent adjacent channel interference. The amplifier also has a Peak Envelope Power (PEP)
rating. PEP represents the maximum peak amplitude power that the carrier can attain
without experiencing significant nonlinear distortion from the amplifier. The various power
configurations are summarized in the table on the following page.
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