designing of omni antenna with 6dBi or more gain with patch

[mainak001]

I want to design an omni antenna with following specification

(a) Frequency range of operation: One spot frequency between 1 GHz and 1.6 GHz,
(b) Gain of the antenna: Of the order of 6 dBi.
(c ) Gain ripple: 1 dB.
(d) Bandwidth: about 100 MHz (10 dB return loss)
(e) Beamwidth in the circumferencial plane: 360.
(f) Beamwidth in the vertical plane: about 120.
(g) Polarization: Vertical

the element will be patch element .power is 2-3 watt .

please help me .

 

[vfone]

Re: designing of omni antenna with 6dBi or more gain with p

Collinear Antenna would be fine for your application.
Here is an example for 2.4GHz:
https://martybugs.net/wireless/collinear.cgi

 

[Chest]

Re: designing of omni antenna with 6dBi or more gain with p

Yup, collinear antenna. Here is another example too.

 

[Azulykit]

Re: designing of omni antenna with 6dBi or more gain with p

I think you need to think about your specification. The elevation beamwidth you specified is wider than a dipole by about 50%, yet you are asking for 6 dBi. Consider that a dipole is 2.1 dBi. Increasing gain implies decreasing beamwidth.

Do you really need a patch antenna? Why?

 

[mainak001]

Re: designing of omni antenna with 6dBi or more gain

thank u all for the reply . ur tutorila ha helped me a lot .

i want to use patch because of its conformal nature , printed facility and low aerodynamic drag ..

i want to make a WRAP AROUND ANTENNA .

please help me in this regard .

 

[Azulykit]

Re: designing of omni antenna with 6dBi or more gain with p

What about the 360 deg by 120 deg coverage? You cannot achieve that in a fixed antenna and 6 dBi of gain.

 

[mainak001]

Re: designing of omni antenna with 6dBi or more gain with p

So, if i want to make 360 deg by 120 deg .. max how much gain i can get ?

 

[Azulykit]

Re: designing of omni antenna with 6dBi or more gain with p

As I said earlier a dipole has about 2.1 dBi and less elevation bandwidth than you specified.

I would suspect that at best you would see around 0 dBi with a relatively efficient antenna feed and even that much might be a challenge.

 

[mainak001]

Re: designing of omni antenna with 6dBi or more gain with p

Hmmmmmmmmm. thanks fr the suggestion .



Now i haver a plan . If it would be possible i don't know but just see it if it can do !!


i will have an array of 5-6 antenna s which are cpw fed folded notch antenna . The pattern form one intersects other and ultimately in total effect it produces an omni like pattern not actually omni .. that gain ripple shd be as less as possible . I will wrap this array outside of cylinder .

Will it be possible . If possible with that gain how much elev and azimuth we can cater ?

 

[Azulykit]

Re: designing of omni antenna with 6dBi or more gain with p

The gain will depend on the beamwidth of your element orthogonal to the roll axis.

What is the pattern of the element you are contemplating?

A first gain approximation would be 10 log (42000/(Θ * 360). This is not exact.

 

[mainak001]

Re: designing of omni antenna with 6dBi or more gain with p

first i want to thank u fr the hlp i am getting "Azulykit"

for finding out the required pat . i am using an infinite series summation of Hankel function of the second kind and its derivative .
the cylinder dia is 1m i am using axial patches with corporate feed network . the dimension is 1.5lambda * 0.5lambda.. subs er=2.5. h=0.159 cm .

 

[biff44]

Re: designing of omni antenna with 6dBi or more gain with p

Chest, in that antenna you suggested, exactly how do you connect to the "driving point" in the diagram. Lets say you had a coax cable, I can see the center conductor connecting to the "driving point", but where do you connect the ground return/shield?

 

[mainak001]

Re: designing of omni antenna with 6dBi or more gain with p

IF we want to fed it via coax then the inner conductor will touch the + port and two outputs from the outer conductor will touch the -ve port .

 

[Chest]

Re: designing of omni antenna with 6dBi or more gain with p

Chest, in that antenna you suggested, exactly how do you connect to the "driving point" in the diagram. Lets say you had a coax cable, I can see the center conductor connecting to the "driving point", but where do you connect the ground return/shield?

"Driving point" is fed by probe (coaxial cable). Inner conductor (core) is connect to the narrow trace/top and outer conductor (braid) is connect to the wide trace/ bottom.

Hope this help.