Measurement of Radio Receivers´ Front-End Nonlinearity by the Frequency Slipping Technique

An incremental technique for measuring the power transfer characteristic of the radio receivers´ input units is proposed. The technique is useful in frequent cases when this characteristic can not be measured directly because of the distortions introduced by the receiver´s back-end nonlinearity and by the automatic gain control. To avoid those distortions, the level of the intermediate frequency output signal is maintained constant during the measurements (which is reached by tuning the test signal out from the receiver´s working frequency simultaneously with increasing the test signal level). Experimental results illustrating the efficiency of the proposed technique are given.