Linearity measurement of 6G receiver with one transmission frequency extender operating at 330 GHz
The future sixth-generation (6G) is envisioned to support data rates up to 1 Tbps. The operational frequencies of the 6G system will be expanded towards the sub-mmW and THz regions. The 6G systems will utilize directive beams, as well, to compensate increased signal attenuation between link ends. The linearity of a receiver (Rx) is one of the most significant parameters for any radio system. Traditional Rx linearity measurement relies on a two-tone measurement technique, which requires two dedicated RF signals and combining them to the test signal. The generation of two independent RF signals at a 300 GHz frequency band leads to a costly and bulky solution. This paper proposes a linearity measurement method for 6G Rx, which uses only one continuous wave transmission frequency extender. A method is proposed where the RF input signal of frequency extender is narrowband amplitude modulated (AM), generating side tones around continuous wave carrier. The carrier frequency and first side tones are used as test signals, and the linearity test is like a traditional two-tone test with unequal signals. It is shown that the carrier level can be modified by back-offing the RF input power in the frequency extender input. By varying the AM modulation index, the side tones’ levels can be varied, enabling the sweep of the tone input power to perform Rx linearity measurements.