Impedance Matching

impedance matching networks applied to RF power TransistorsMOTOROLA

Freescale Semiconductor, Inc.

SEMICONDUCTOR APPLICATION NOTE
NOTE: The theory in this application note is still applicable, but some of the products referenced may be discontinued.

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Impedance Matching Networks Applied to RF Power Transistors
Prepared by: B. Becciolini

1. INTRODUCTION
Some graphic and numerical methods of impedance matching will be reviewed here. The examples given will refer to high frequency power amplifiers. Although matching networks normally take the form of filters and therefore are also useful to provide frequency discrimination, this aspect will only be considered as a corollary of the matching circuit. Matching is necessary for the best possible energy transfer from stage to stage. In RF-power transistors the input