Low Profile omni directional indoor celing mount antenna for GSM 900, 1800 and 2100

Does anyone out there have any suggestion on the design of a low profile ceiling mount for LTE?

Antenna type etc. ( No higher than 40 mm and L x W < 100 x 100 mm^2)

Also the H plane pattern must be omni directional and across all bands.

Gain 0 - 3 dBi

All suggestions welcome

you can make a simple dual band monopole which should meet your specs.

(824-960MHz and 1710-2170MHz) --> Is this the frequency of operation ?

Let me start by saying an omni-directional antenna is a practical impossibility. Besides you only need to cover a hemisphere. So I agree with the other comment: use a monopole mounted over a small ground plane to get a wide coverage.

There are also ways of getting wide angle performance out of patch antennas if you are looking for something thinner than a few cm.

Hi sorry to crash into this thread. I am building a dual band quasi Yagi antenna to receive GSM 900 and 1800 frequency band. Is there a way to improve the s11 parameters through physical changes made in the design of the antenna?