wideband L-probe feed, did you hear about?

[Lupin]

to rfary:
the antenna is for space or ground applications?

in general:
the design is good, in my opinion this is one of the best configurations for antenna compactness and envelope... My main requirement is Gain more than 8 dBi..

Best regrds
Lupin

 

[rfary]

the author didn't used it in full application. its just a single patch antenna to see whats the bandwidths and polarisation is like.

 

[ruth]

dear lupin:
the structure of my antenna is as the same of yours (the frequency is around 3GHz),circular polarized,my aim is gain 3db within 12%bandwith,but now the gain is very low(about 1db,below 0db at somepoint)! i want to improve the gain too! it's a big problem!

 

[Lupin]

Hi Ruth,

u can use dielectric with high er for the feeding microstrip and low er (and thick) for the materials supporting the stacked patch.
In this way the Gain will increase.
Be careful to the excitation of Higher Order Modes.
How many inputs are u using to feed the antenna?
What e.m. code are u using?

Best regards
Lupin

 

[ruth]

hi lupin:
now my lower substrate(feeding one) is er=4.6(h=1mm),the up substrate is er=2.65 (h=4mm),just one input ,that is to say one microstrip flows over the four sides of the cross aperture ,90 degree phase lags one side by one side.
but how to know the higher order modes?
what's more i think your 8db gain is very difficult,do you think so? wish you success

 

[Lupin]

To ruth:

Number of inputs: I suggest 2 inputs (or even 4) to avoid mutual coupling and excitation of Crosspolarization (paraters affecting Antenna Gain). Use a branch-line or a gap coupler;

Layer configuration: u didn´t give information about stacked p@tch antenna. U spoke about layers behind the slotted ground plna.. am I right?

Higher modes: observe the radiation pattern (the easiest way)

Code: what code are u using?

Regards
Lupin

 

[mamali]

I ever designed 2polar L-probe antenna, the isolation is bad

use a L-probe for one pol and a aperture feed for another, Luk have a paper on it on IEEEEXPLORE. just search it with L-probe term

 

[mamali]

well, lupin, one way to increase the gain is to use a high permittivity (71 forexample) sub as a superstrait.

 

[Lupin]

Do you have this article? What ´s their frequency?

Can u upload it?

Thanx in advance.

Lupin