Dielectric Lens Antenna

[Admin 2838]

A horn antenna is one of the most commonly used antenna types for a focused antenna. However, the horn antenna is limited by its dimensions, which must have a certain size relative to the wavelength in order to work properly and efficiently. Since this will typically be too large to fit into the flange, a dielectric lens antenna with reduced dimensions is developed. The lens has the spherical form which is able to enhance the gain by making use of guided surface waves. The antenna is fed by a circular waveguide and at the boundary of the dielectric half space. A stepped impedance transformer has been introduced in order to provide broadband input matching impedance.

Dielectric rod antennas refer to traveling wave antennas with a slow phase velocity (vf< s). They are used at the border of the centimeter and decimeter wave ranges in the frequency band from 2 to 10 GHz.

Dielectric lenses are made of materials with high dielectric constants, such as polystyrene, polyethylene, and plexiglass. They can be integrated with various types of feeds, such as horn antennas, microstrip antennas, and waveguide antennas.

 

[Admin 2838]

,,,and here is how you can get an increase in directivity  with a dielectric feed(polystyrene) on cantenna,,,

 

 

[Admin 2838]

,,, and another version with a spherical dielectric lens, which have diameters  244 and 305mm...

[Admin 2838]

[Hamza 47]

So cool...

[Admin 2838]

After so many years I tried to recreate this antenna with the dielectric lens....

[clanon 332]

Try this : Luneburg lens the Dielectric Constants should be changing from low outside to hugest in the core (twisting the Beam  towards the center)

https://www.analogictips.com/wp-content/uploads/2023/08/WTWH_Luneburg_lens_Pt3_Fig4.png

also flat disc

https://www.sciencedirect.com/science/article/pii/S2211379724000329

Edited November 23, 2025 by clanon

[Admin 2838]

This is harder to build...

[Admin 2838]

The dielectric constant of styrofoam (expanded polystyrene) is approximately 1.02–1.04. This low value is due to its low density, which consists of air bubbles (with a dielectric constant close to 1) and the polystyrene material itself. The dielectric constant of solid polystyrene resin, without the air pockets, is higher, ranging from 2.4 to 2.6. 

For expanded polystyrene (styrofoam): The dielectric constant is approximately 1.02–1.04, which is a very low value due to the high volume of air in the foam.

For solid polystyrene resin: The dielectric constant is higher, ranging from 2.4 to 2.6.

Factors influencing the value: The dielectric constant is influenced by factors such as density, moisture, temperature, and frequency.

Frequency dependence: While the dielectric constant of solid polystyrene is relatively flat up to 1 GHz, the value for the foam is measured in specific ranges, like 100-400 MHz.