Hello to all,
I am working on a project for channel measurements in an indoor environment and my part of this project is to design and
construt 2 quarter-wave monopoles for 2 different operating frequencies( one for 900MHz and the other for 2.4GHz).
The antennas will be made with a PCB(which is not my responsibility) and a ground plane.
I have found some information about the design but I would appreciate any additional info that you can give me.
Thanks in advance
i think u can made an antenna monopole on pcb like microstrip antenna
There are various planar antennas comprised of a copper pour and a straight or folded/bended trace, that can be analyzed as a kind of monopole. Like the below one from a TI application note. But these antennas are compromise designs and don't implement a straightforward design principle. In so far, I don't hear a clear question from the original post, or at least can't give a simple answer.
Of course no copper on the back side.Is there copper on the back side of the PCB, directly below the monopole, or is the only ground the flooded metal surrounding the chip?
Yes, you can read "compromise design" as another word for "not a very good one". Nevertheless, similar designs serve their purpose. I also did one for a wireless product.I could see the latter working as a monopole, just not a very good one.
........... In so far, I don't hear a clear question from the original post, or at least can't give a simple answer.
what additional help do you need? ask a specific question
is there something in what you have been reading that you dont understand ?
A monopole antenna on a PCB ground plane is about as basic an antenna as you can get
You could use semi rigid coax like UT-141 bring it up through a hole in the centre of the PCB ground plane, solder the upper side of the ground plane to the solid outer conductor of the coax and use the centre conductor as the radiator. You could leave on the teflon dielectric for added protection or strip it off. Being on or off will affect the tuning slightly, either way ensure that you cut the length of the radiator a bit longer than needed and then trim it down to get a good return loss.
Cheers
Dave
First of all, thank you for your precious help.
What I was thinking is that I will use a pcb laminate(with fiber glass) which will have copper sheet at the bottom side and there we will solder a right angle sma connector.
I will connect to the connector a sma rf cable.
Also, I will drill a hole in this part to place the antenna.
Do you have any papers to read for that type of design?
Finally, I would like to learn about the cost of such a design, ie the pcb laminate, the connector, the brass rod and the sma cable.
Thanks in advance
Dave, I want to thank you for your advice too.
One more question to you and enjunear.
I have read that the are of the ground plane should be λ/4*λ/4.
Why do you propose the PCB sheet to be 2Xλ/4?
Is this for performance reasons?
Thanks in advance,
Manos
---------- Post added at 19:38 ---------- Previous post was at 19:07 ----------
[/COLOR]Also if we finally use a double sided PCB, does anything in our change?
One more thing, about the thickness. In the labs university I have access to a PCB with 0.8mm thickness and one of 1.6mm thickness?
Does it make any difference if I use the thinner one?
PS. Are you aware of any books specifically for antenna design with information like those that you gave me?
Regards,
Manos
I have read that the are of the ground plane should be λ/4*λ/4.
Why do you propose the PCB sheet to be 2Xλ/4?
Is this for performance reasons?
The easiest way to use a two-layer PCB is to just etch off (or peel off) the top layer copper and simply use the bottom layer metal to install your SMA connector.Also if we finally use a double sided PCB, does anything in our change?
One more thing, about the thickness. In the labs university I have access to a PCB with 0.8mm thickness and one of 1.6mm thickness?
Does it make any difference if I use the thinner one?
My favorite text book is Antenna Theory by C.A. Balanis. It's very math intensive and theory-based, so not for beginners. For entry-level antenna design, look at the ARRL Antenna Book. ARRL is the amateur radio group (HAM radio enthusiasts), so most of their documents/books are based more in practice than theory.PS. Are you aware of any books specifically for antenna design with information like those that you gave me?
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