Читать книгу Fundamentals of Terahertz Devices and Applications - Группа авторов - Страница 35

It is common to use an elliptical silicon lens antenna to be integrated with a high frequency detector. The detector, which operates at 350 GHz, it is placed on silicon (ε_r = 11.9). In order to couple the radiation into the detector an antenna consisting of two slots is used.

1 Give the length and separation of the slots in order to generate a field radiated inside an infinite silicon medium that could be used to illuminate efficiently the lens.

2 Design the lens dimensions such that its far field is characterized by a directivity of 30 dBs.

3 What are the sidelobe level, directivity, and reflection efficiency of lens antenna?

4 Assuming we aimed at the same directivity of the lens antenna, how would the two slot antenna and lens dimensions change if the dielectric material was εr = 4? What about the reflection efficiency?

Justify your answers with figures and try to give a physical insight into the problem.