UWB Patch Antenna

[fwbsys]

Hi @ all,

I'm new to the subject UWB Antenna Design.

Whats the best starting point to create a small, directed, wideband patch Antenna with a short Impulse Response?

1.) How can I influence the Impulse Response of the Antenna to shorten it?

2.) Whats the best Way to match the Antenna impedance to the 50Ohm Cable Impedance?

2.1) Is a symmetric connection better?

3.) Is there any possibilty to get a better directivity (beamwidth) of the Patch (i tried Absorber at the backside but in the front direction i have not so much room)

4.) I need a frequency range from 500MHz to 5GHz any sugesstions for good good shape. At this time I'm using ellyptical patches which have a frequency range from 1.2Ghz to 3.5GHz but they have a bad directivity and long Impulse Response

Hope anyone has some suggestions

Ciao
FWB

 

[Higgler]

I've never seen a Patch and UWB combined in the same sentence. Most UWB antennas are not flushmounted over a ground plane. Plus most UWB antennas are 4:1 bandwidth, not 10:1. The widest usuable bandwidth patch antenna I've seen is 50%.

I've made a 0.5-2+ Ghz UWB antenna, a Vivaldi notch over a ground plane, 8" tall x 17" long. Would look like a long blade antenna on an aircraft.

Small and directed antenna are opposing terms also. If it's small, it can have high directivity unless you block it's view with alot of absorber.

The closest I've seen to your needs is a "UWB window antenna", 9" square frame (for 500 Mhz low end) with a printed circuit in the center which can be flush mounted with absorber behind it, depth would be around 6" using 4.5 inch thick AN-79 absorber, hence 9"x9"x6", but the VSWR goes bad below 0.5 ghz and above 2 Ghz for the standard design, getting up to 5 Ghz would take some real experienced HFSS optimization. It is a UWB design according to the article I read.

kch