Full-span error calibration method for on-chip quadrature accuracy measurement

This study focuses on a full-span calibration and detection methods of an on-wafer measurement system for quadrature voltage-controlled oscillator (QVCO). The quadrature accuracy, namely I/Q imbalances, of the QVCO was accurately measured by a high-speed oscilloscope. An on-chip calibration kit (Cal Kit) was applied to de-embed the system errors. This paper describes the test setup and calibration procedures in detail. The proposed method provides an effective full-span vertical calibration, skew calibration, and phase and amplitude differences measurement in an on-wafer measurement system. Finally, a 5 GHz QVCO was fabricated to verify the proposed methodology.