The carrier aggregation technique will allow an increase of capacity of the 4 th Generation mobile communication networks (LTE-A: Long Term Evolution Advanced). The probability to find carriers that occupy a continuous spectrum in frequency is very low. The challenge is to demodulate an RF signal where the information is distributed on non-contiguous frequency bands. The technique presented in this paper concerns the mixing of n modulated carriers with n Continuous Wave (CW) signals by using a single three phase demodulator circuit. This technique allows reducing the conversion band of the Analog to Digital Converter (ADC) to 100 MHz. The principle is theoretically demonstrated for three non-contiguous carriers and validated by measurements results. The test was made for modulated carriers of 10 MHz or 15 MHz bandwidth by using the same QPSK modulation format or two different modulation formats (QPSK and 16-QAM). The demodulation performance is evaluated by measuring the Error Vector Magnitudes (EVM) of the transposed signals in baseband. This test shows that it is possible to demodulate a distributed non-contiguous multi-carriers RF signal in the band 2-3 GHz with a bit rate more than 300 Mbps.