E-band transceiver system characterization based on bandwidth dependent linear impairments

This paper presents the performance analysis of a broadband wireless E-band link due to the transfer function's bandwidth-dependent linear impairments and in-phase to quadrature channel leakage at the transceiver system. The transfer function impairments involve the gain ripple, port impedance mismatches, and group delay variations. The theoretical study of the link performance in the presence of the mentioned impairments is performed using a system-level simulation. The impairments associated with the up- and down-converting mixer and the LNA blocks are included in the simulation. To validate the theoretical analysis, the E-band link is measured in a coherent back-to-back configuration. In both the simulation and the measurement environment, the transceiver is working with a local oscillator frequency of 77 GHz. The theoretical analysis is proved through measurements. The simulation and measurement results show a good match with the relative error being less than 5% of the highest value. At an IF bandwidth of 4.75 GHz, the error vector magnitude is increased from 8% (-21.94 dB) to 22% (-13.15 dB) due to IQ channel leakage. Besides the transfer function impairments, the IQ channel leakage is investigated as an important factor on the linear impairments characterization of the broadband millimeter-wave transceiver system.