Abstract
This work aims to provide guidelines on the design of wideband flat lenses based on artificial dielectric layers (ADLs). Planar lenses based on metasurfaces are typically narrowband, due to the phase wrapping over the period of 2\pi that is strongly frequency-dependent. On the contrary, true-time-delay (TTD) planar lenses, which do not resort to phase discontinuities, can achieve large bandwidths. One convenient way to design wideband TTD lenses is by means of ADLs, which are stacks of subwavelength-period patch arrays embedded in a host medium to increase its effective permittivity. Tradeoffs including bandwidth, focal ratio, lens diameter, and thickness are discussed and related to the manufacturing constraints of artificial dielectrics, such as the smallest features realizable in printed circuit board (PCB) technology, which define the maximum achievable effective permittivity. An example of design is also presented, operating from 30 to 60 GHz and experimentally validated.
| Original language | English |
|---|---|
| Pages (from-to) | 1418-1428 |
| Number of pages | 11 |
| Journal | IEEE Transactions on Antennas and Propagation |
| Volume | 72 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - 2024 |
Bibliographical note
Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-careOtherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.
Keywords
- artificial dielectrics
- flat lenses
- true-time-delay lens
- ray tracing
- wideband lenses