The MultiMatch Circle Module allows for specification of the noise figure, the operating power gain, the available power gain, the transducer power gain or the output power (Power Module Option) required from the stage designed over the frequency range of interest. The specifications made here are used to design the lossless control network (impedance-matching network) associated with the (modified) transistor in the stage designed.

A table of the expected best and worst performance associated with the specified gain or noise figure targets (summary table) is provided directly after the specifications were made. Based on the potential results, changes may be required in the performance targeted.

The performance around the constant operating or available or transducer power gain or the constant noise figure circles targeted, and the influence of tolerances in the admittance provided by the matching network to be synthesized, can be evaluated numerically. The expected output power or the effective output power is also calculated when this is done (Device-Modification and Circle Module Power Option). An error function is used to decide on the optimum point on each circle or contour. The parameters of this error function can be modified by the user when the summary table associated with the target specifications are displayed. The load or source termination at any frequency can be forced to a specific point on a constant gain, constant noise figure or constant output power contour ("point-match" versus "circle-match").  Zoom capabilities are provided in the tables displayed. The impedance/admittance/reflection coefficient of the source or load terminations are now also listed in the tables.

The optimum load or source terminations can also be displayed graphically, with the associated gain and the input or the output reflection coefficient. When the load terminations are displayed, the output impedances with the input terminated in a conjugate match or the source termination of the stage (transducer power gain option) are also displayed. The input impedance with the output conjugately matched or terminated in the load impedance of the stage (transducer power gain option) is displayed with any source terminations.

Constant gain circles, constant noise figure circles and contours of constant output power or constant effective output power (Power Module Option) can also be displayed graphically. Up to three circles/contours can be displayed per frequency for up to four frequencies. The circles/contours for the lowest and the highest frequencies in the passband, as well as those for two frequencies inside the passband, are displayed. Two sets of contours can also be displayed simultaneously.

The contours generated in the circle module can be used as background graphics at a later stage to evaluate the performance of the gain or the noise figure or the power control network synthesized graphically.

The specifications for a lossless control network which will provide the specified performance (the equivalent passive problem) are set up automatically when the gain or the noise figure or the output power required has been specified. The defined equivalent passive impedance-matching problem must be solved with one of the impedance matching modules. The solutions synthesized to solve this equivalent passive problem can be optimized for the best active performance in the results sections of the impedance-matching modules.

A worst-case tolerance analysis can be done for each solution displayed in order to establish the sensitivity and to choose the most suitable solution. The performance of each solution synthesized can also be displayed graphically with the contours generated in the circle module as background graphics.