Precise wideband millimeter wave signal generation with frequency multiplier based transmitters

With demands for ever higher data rate wireless communications and very wideband sensing, wideband signals at carrier frequencies in the millimeter wave frequency range are being targeted. An emerging evolution is to adopt frequency multipliers (freqX) in the transmitter chain, as to boost the carrier frequency strongly with minimal radio-frequency electronics as compared to the traditional mixer-oscillator stage. Two goals are targeted in this project: (objective A:) the characteristics of the input signal are to be preserved at the freqX output (application: wireless communications), and (objective B:) a predefined wideband excitation is to be generated precisely at the freqX output (applications: radar and metrology).

Regarding objective A, the main challenge is to conceive a proper signal predistortion methodology, considering the strong intrinsic nonlinearity order of freqX. By in-depth forward and inverse modelling, the project targets to achieve results for signals with bandwidths an order of magnitude larger than the state-of-art. Regarding objective B, the idea is to exploit intentionally the bandwidth expansion property of freqX's nonlinear operation as to achieve precisely predefined wideband signals. In addition, preserving signal quality when loading the freqX by the next block in the transmitter, will be investigated for the first time. Throughout the project, there is strong emphasis on real-life proofs-of-concept with extensive measurement validation.