[Paper] Time-Efficient Adaptive Procedure for Identification of Multitone X-Parameters

Konstanty Łukasik , Graduate Student Member, IEEE, Paweł Barmuta , Member, IEEE,

Troels S. Nielsen, Member, IEEE, Wojciech Wiatr , Life Member, IEEE,

and Dominique M. M.-P. Schreurs, Fellow, IEEE,

"Time-Efficient Adaptive Procedure for Identification of Multitone X-Parameters" 

in IEEE Transactions on Instrumentation and Measurement, 

vol. 72, pp. 1-9, 2023, Art no. 1000609,

DOI 10.1109/TIM.2022.3232171.

Abstract: A novel measurement procedure for the time-efficient identification of multitone X-parameters of active microwave devices and circuits is introduced. Over a given bandwidth, the procedure allows for an adaptive selection of key spectral components necessary for determining the X-parameters characteristics with a minimum measurement effort. The sequential selection is based on the divide-and-conquer algorithm. It results in a huge reduction of the measurement time in comparison to the situation when model coefficients at all spectral components are identified. To validate the procedure, an off-the-shelf broadband power amplifier (PA) was characterized under wideband large-signal excitation conditions. Moreover, small-signal terms at all relevant frequencies were collected as a reference and compared with the results provided by a time-efficient adaptive procedure (TEAP). The proposed method resulted in twenty times reduction in the number of samples required to characterize the PA. As an application example, the small-signal coefficients identified with the TEAP are used to correct characterization results for the measurement instrument’s output mismatch. The mismatch-corrected output signal of the PA under test was represented accurately with the error-vector-magnitude of only 0.132%.

FIG: Block diagram of the measurement setup used for performing experiments.