Large-Signal Network Analyzer Measurements benefit Transistor Modeling Ahmed Alabadelah, Telemic - ESAT Marc Vanden Bossche, NMDG Engineering  Copyright 2003 NMDG Engineering bvba

2 Overview What is a Large-Signal Network Analyzer (LSNA) measurement? The LSNA advantages in device modeling LSNA Measurements in ICCAP Acknowledgement Conclusion

3 What is a LSNA Measurement? Transistor RFIC System Realistic Stimulus Realistic Stimulus Measurement System Physical Quantity – Travelling Waves (A, B) – Voltage/Current (V, I) At all device ports Representation Domain – Frequency (f) – Time (t) – Freq - time (envelope)

4 What is a LSNA Measurement? Complete and accurate characterization of a HF component –Complete the information of the measurement describes completely the state of the device under test the interaction of the measurement system with the component is taken into account –Accurate the measurements are traceable to standards (calibration kit, power and phase standard) Under a large stimulus –There is a signal present that potentially results in nonlinear behavior of the component Under realistic stimulus –The stimulus can be chosen close to the signals used in reality Limitation –The stimulus needs to be periodic

5 The LSNA advantages in device modeling Measure all characteristics of your DUT making a single connection, using one measurement setup (the LSNA) –DC (static I/V characteristic), –Small-signal (Scattering parameters), and –Large-signal behaviour (dynamic I/V characteristic) Qualify the model accuracy of your device under realistic operation conditions as used in designs –power amplification under dynamic conditions –tuning conditions –high-speed switching Identify modeling problems at a single glance –LSNA measurements, e.g., immediately reveal weaknesses in capacitance and charge models

6 LSNA measurements in ICCAP [Courtesy of Agilent Technologies] Measurement of component behavior under different conditions power frequency bias impedance continuous wave modulation sweep of Power Vgs Vds Freq Coupling of measured characteristics in ICCAP Model Qualification in ICCAP Quiescent bias Dynamic Loadline“Dynamic gm” BeforeAfter Model Tuning in ICCAP

7 Acknowledgement Dominique Schreurs (K.U.Leuven) Wladek Grabinski (Motorola Geneva) Ewout Vandamme (ex - colleague Agilent Technologies) Agilent Technologies Ahmed Alabadelah, who volunteered to present this presentation

8 Conclusion Unique tool for complete large-signal model accuracy assessment under realistic RF or microwave signals Reduce number of design cycles and reduce manufacturing costs by anticipating realistic behavior at the transistor level Optimize model parameters to LSNA measurements for better simulation predictions Benchmark various device models, e.g., –BSIM versus MM11 versus EKV versus … –VBIC versus MEXTRAM versus HICUM versus... Build confidence in your model NMDG Engineering provides a LSNA measurement service More information / questions : GSM