The fundamental tone (linear) output power of a transistor is mainly limited by clipping of the intrinsic output voltage and the intrinsic output current. The clipping area is defined in MultiMatch by four boundary lines on the I/V plane (if available, the pulsed I/V curves should be used). The boundary lines to be used must be defined (with the bias point) in the S-parameter Module. A load-line factor is used in the Power Module to indicate the amount by which the input signal must be scaled in order for the intrinsic output voltage and the intrinsic output current to fall within the defined area (linearity assumed).

The maximum output power (P_out) or effective output power (P_out-P_in) available from the device used is estimated first on entering the Power Module (Note that the effective output power should be considered when an oscillator is synthesized). The target power level and the power levels associated with any additional contours required can then be specified. The potential performance on the target contours are summarized first in a summary table before the additional contours are generated and the results section of the Power Module is entered. The contours generated can be displayed graphically with the optimum load termination in the results section of the Power Module. When the optimum terminations are displayed, the output impedance associated with a conjugately matched input port is also displayed. Note that the input port may also be terminated in the source impedance of the stage, if relevant (G_T option).

Up to three power contours at up to four frequencies can be displayed simultaneously. The contours at the lowest and the highest passband frequencies and at two frequencies inside the passband are displayed.

The performance around specified constant output or constant effective output power contours can be listed numerically too. The optimum point on a constant power contour can be selected ("point-match") by high-lighting it. Zoom capabilities are provided in the tables displayed.

The (default) optimum point on each contour is selected automatically by using an error function. The parameters of the error function defined for this purpose may be modified by the user. This can be done when the summary table is displayed after specifying the target power levels.

Apart from generating constant power contours, the expected performance can also be calculated for a specified intrinsic load or for a specified external load.

The influence of voltage-shunt feedback, current-series feedback and series and shunt loading can be taken into account when the power is calculated or the contours are generated. The pads or connecting lines required can be specified electrically or, if a microstrip substrate is to be used, geometrically. Any modification components, pads and connecting lines required must be specified in the Device-Modification Module.

An impedance-matching data file can be created automatically for the power problem in the file creation section of the Circle Module.