OIP3 and P1dB

OIP3 = third order intercept point ==> better than anything i could write ==> http://en.wikipedia.org/wiki/Third-order_intercept_point

P1dB = 1dB Gain Compression Measurement ==> An amplifier maintains a constant gain for low-level input signals. However, at higher input levels, the amplifier goes into saturation and its gain decreases. The 1 dB compression point (P1dB) indicates the power level that causes the gain to drop by 1 dB from its small signal value.