Gain compression points are quoted often and easily in datasheets, specifications and elsewhere. However to really use this data one needs to know what these numbers allude to and how they can be used. To learn more about gain compression please refer to the post by Signal Processing Group Inc. ( at the following link: www.signalpro.biz/pointsf1.pdf ). However this post simply reiterates the relationship between the input 1 dB compression point, the output 1 dB compression point and the small signal gain. The expression is: Pin( 1 dbCP) in dBm =Pout(1dbCP) in dBm- [gain(db)-1] ( in dBm). So if the output compression point is known one may back calculate the input 1 dBCP using the small signal gain of the device. ( or vice – versa).