Experimental Verification of the Smoothie Database Model for Third and Fifth Order Intermodulation Distortion

Abstract

The experimental intermodulation verification of the Smoothie table-based model for FET devices is presented. The model is implemented in the Agilent's Advanced Design System (ADS) circuit simulation program and is based on the smoothing spline approximation of the device Y-parameters. The device main functions, i.e. the terminal currents and charges, are calculated by the analytical line integration of the Y-parameters. The use of smoothing splines yields continuous higher order derivatives and, consequently, the correct simulation of higher order intermodulation products. The latter is of paramount importance in the development of 3G PA applications.The results presented show excellent agreement between the measured and modelled intermodulation distortion as function of bias and power.

Extraction and modelling of self-heating and mutual thermal coupling impedance of bipolar transistors

“…An alternative approach in nonlinear thermal impedance modeling is the database (or look-up table) modeling method based on measured small-signal thermal impedance data. Such a thermal database model coupled with an electrical model (compact or database [40]) can then be used for accurate large-signal electrothermal analysis of devices and circuits. With the lock-in measurement technique presented here, the small-signal thermal impedance data at constant temperature can be extracted versus frequency and used to create thermal impedance models.…”

RF Power Silicon-On-Glass VDMOSFETs

“…Furthermore, pulsed S-parameters were measured on a large grid of bias points. This measured data, which also contains all the device parasitics, was used without scaling as input for the Smoothie database model that has already been proven to yield very accurate calculations of RF performance [15]. Smoothie load-pull analysis at 2 GHz yields, in class-AB bias conditions, a two-tone power gain as high as 14 dB, and IM3/IM5 of dBc at 10-dB backoff [ Fig.…”