Appendix 5

Wideband Impedance Matching: Dissipative Two-Port Networks

We will now detail the calculations relative to the wideband matching for two types of circuit characteristics of the transistors: the series-RC and the parallel-RC circuits.

A5.1. Series-RC circuit

Consider a series-RC-type circuit as shown in Figure A5.1.

Figure A5.1. RC-series-type load impedance

c-fig-001

The reflection coefficient normalized from reference impedance R0 is written as:

images

A normalized frequency can be defined as:

images

The variation as a function of the normalized frequency images is shown in Figure A5.2.

Figure A5.2. Module of the series-RC-type reflection coefficient

c-fig-0002

The low-frequency matching is obtained thanks to parallel resistance (Figure A5.3).

Figure A5.3. Series-RC resistive matching

c-fig-0003

The reflection coefficient is written as:

Matching is achieved with gl = l, that is

Figure A5.4 shows variation as a function of ...

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