Monday, August 31, 2009

Review of microwave propagation and scattering parameters

I hope the quiz last week tested briefly your understanding of radio wave propagation. Microwave propagation is interesting because of the many ways the waves interact with objects and media along the path.

You should by now appreciate the mechanisms of microwave propagation. Lest one forgets, we are talking of not only terrestrial but also space communications using microwaves.

The next topic to be discussed would be microwave networks. Here, a network is meant to be a device (active or passive) that accepts signals at microwave frequencies. We would see that low frequency network representation fails at microwave frequencies. We need to introduce a new set of parameters to describe the networks.

At microwave frequencies, we do not use open-circuit and short-circuit tests as these would introduce oscillations and irradiations. To ensure the system is stable, we use matched load tests. The result would be the scattering parameters.

see you in class.

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