SOA is a small size nonlinear amplifier
that offers advantages to be integrated to produce a subsequent system essential in optical communication system.
Active tuners are preferred because many classes of nonlinear amplifier
operation ideally require a reflection coefficient of 1.0 at harmonic frequencies.
The transfer function of a weakly nonlinear amplifier
can be expressed in a Taylor series form as
Sidelobes are the result of the spectrum regrowth when a digitally modulated signal is applied to the input of a nonlinear amplifier
. IM products are the result of the creation of additional products when sinusoidal (CW) signals are applied to the input of the same amplifier.
VSS behavioral models have also been extended and the software now uses a seventh-degree model for a nonlinear amplifier
, which includes noise as well.
In a weak nonlinear amplifier
, the input and output voltages can be expressed using a power series.
For experimental validation, the estimated CIR is compared to measured results of the output signal CIR of a 1.9 GHz nonlinear amplifier
fed by a CDMA signal over a range of power levels.
If a desired carrier signal and band limited noise is applied to the input of a nonlinear amplifier
, as shown in Figure S1, then transmit band noise will be folded around the carrier frequency.
Spectral analysis has been performed on both the ideal modulator output and the nonlinear amplifier
Intermodulation results when two signals separated in frequency by f are input simultaneously to a nonlinear amplifier
. The output of that amplifier will be the amplified signals at the two frequencies plus intermodulation products.
The digital waveform input allows a variety of measurements, including single tone and two tone and a variety of more complex modulations, which can display the trade-offs between nonlinear amplifier
operation and communications system parameters.
The assumed instantaneous nonlinear amplifier