UWB printed antenna doubts

Hi to all,

I'm begining in the field of UWB RADAR and its antennas and I need some basic info before to look for other things. I'm building an UWN transceiver and I need an antenna with the following features:

a) Printed on a normal doubled sided FR4 PCB
b) Unidirectional
c) Possibility to change Azimuth and Elevation (Of course, if no possibility I supose that that I will need to design a different antenna for each case)
d) The more adecuated software to design this kind of antennas.

My doubts are, for instance, what kind of antennas, monopole or dipole or other, bow-tie or an array of patches, etc. I've a lot of books and documentation but no one has the answer.

Please, tell me your suggestions and my apollogis for my ugly English.



P.S. E-plane and H-plane is the same thing as Elevation and Azimuth?.

There is a tremendous amount of information on UWB antennas.

Your P. S. question caught my attention.

E and H patterns refer to radiation patterns cut in the plane of the electric and magnetic field planes respectively. Azimuth and elevation planes are relative to the earth. Azimuth is taken to be horizontal and elevation is vertical. Watch the definition of 0 degrees in elevation carefully. Some use zero to be straight up and others use it to indicate horizontal.

The short answer is no they are not the same (sometimes).

What is UWB radar? What is its applications?

UWB is a modulation technique where a signal is spread over a very wide bandwidth. It is collected and collapsed upon reception for additional processing.

It falls into a class of devices considered as spread spectrum. Look into frequency hopping, direct sequence spreading, impulse radiation, OFDM (orthogonal frequency domain modulation), C-Wave, ground penetration radars, quiet radars, among the related areas.

The challenge for an antenna designer is to produce multi-octave antennas for these devices.

Dear Azulykit,

There is the rather common planar "volcano-smoke" PCB antenna that you can look into for starters. I am assuming here that you are trying to look at it as a simple transceiver first. It's a whole different ball-game if you're looking at a radar system point of view.

Its design (and variations) of this PCB antenna can be found in recent IEEE papers.

Hope this helps,
Dave

Hi,

i won't suggest using FR4 for UWB printed antenna. You get higher loss at higher frequency range, which is undesirable. You can try other better substrates. The dielectric constant for FR4 is also not very consistent throughout the substrate.
Hope this helps.

Regards

Dear Heedavid,

I am unclear to me why you referenced me in your remarks. I am certainly not offended, more curious than anything else.

The volcano smoke antenna has been around for quite some time. I believe that it was discussed and possibly invented in the early 1940's by Lindenblad. I have never tried to build or analyze one but it looks like it would be a good candidate for broadband usage as an omni. I suspect that it is a challenge to fabricate although now that we have CNC mills and lathes it probably is easier.

This is getting a little away form the original questions of what is UWB radar and what are E and H patterns. I am a relatively new member of the forum and want to play by the rules. Hopefully, this response is still acceptable.