New measurement-based technique for RF LDMOS nonlinear modeling

Abstract

In this letter a new look-up table model is developed for the nonlinear modeling of radio frequency (RF) LDMOS transistors. The modeling technique is based on the use of approximation splines that are coupled to a pulsed I I I-V V V characterization setup. It provides a very fast modeling procedure, while avoiding the appearance of undesired ripples in the modeled functions. The technique has been applied to a RF LDMOS technology for L L L-band applications, obtaining excellent results in the prediction of both the small-and large-signal transistor responses. This technique is specially suitable for fast-evolution technologies.

High‐efficiency class‐C power‐amplifier module

“…This equivalent circuit of the LDMOS FET is composed of the current source, capacitances, and parasitic elements. First, the static parameters have been extracted from the SPICE model-3 formulation for the evaluation of the drain current as a function of voltage between drain and source [3]. Second, the charge-storage effects in the small-signal elements are illustrated by three nonlinear parameters, such as the gate-source capacitance C gs , the gate-drain capacitance C gd , and the drain-source capacitance C ds .…”

“…2), and the solution is given by the (ideally) common intersection of the three circles derived from the measured data [1]. There are different methods to implement the six-port reflectometer, such as using two directional couplers and two voltage probes [2], and using three-coupled lines (coaxial lines, stripline, waveguide, or microstrip lines) [3,4]. Another way is by using a five-port junction (ring or disc) and a directional coupler [5].…”

High efficiency LOW AM/PM 6W C-band MMIC power amplifier for a space radar program

“…A customized table-based model [2] including the main current source I DS (V DS ,V GS ) and the capacitance's C GS (V DS ,V GS ) and C GD (V DS ,V GS ) has been computed to insure the accuracy of simulations even under deep compression levels.…”

Distributed and multiple time-constant electro-thermal modeling and its impact on ACPR in RF predistortion

“…(3) (4) When the media i s a layered structure, boundary conditions are similar as equations (3) and (4), except that they are now time dependent, i.e, they should be satisfied at all time. It becomes now too complicated t o get an analytic solution.…”

“…Analytical electrethermal LDMOSFET models 121 as well as several table based models [3] [4] commonly use a simple singlestage RC circuit to model self-heating effects. This simple single RC circuit may not be accurate enough due to two reasons: 1) the temperature is not uniformly distributed across the active area (see Figure l), and 2) there are multiple time constants (ranging from ,us to s) associated with the heat transfer process.…”