antenna connection problem

[darvaish]

I have got RF modules TXM-418-LR and RXM-418-LR
and the antenna ANT-418-PW-RA from LINX technologies.

I want my antenna to be at right angle to the PCB surface for that what i am thinking to do is to have small tab on the PCB very near to the RF module(because as datasheet says if i can place antenna at <1/8 inch to the module then there is no need for microstrip line) and then connect that small tab to my antenna through a small L shaped copper strip so that my antenna connects at right angle to the board surface
Am i right in doing so ? will it work properly?

Any one who has used this antenna?

 

[BF9000]

New Antenna

Is it out of the question to use another antenna? The particular one you are using seems poorly suited for that type of mounting. The way you described will work, but may not be ideal. If you are looking for something more optimal, you may want to try one of the CW series. It will also help a great deal to use a ground plane on the opposite side of the board to act as a counterpoise for you 1/4 wave antenna.

 

[darvaish]

Thanks for your reply

I cannot use any other antenna because i have already purchased this RA series antenna.

I have made a double sided PCB for it whose one side is acting as a ground plane

The way you described will work, but may not be ideal.

Can you please explain why it will not be ideal?How much degradation will occur with this kind of implementation?

I talked to LINX people and they told me to have a small tab on my PCB and screw the antenna to that tab.But as i have a ground plane underneath connecting this antenna in this way through a screw will short circuit the antenna connection to the ground plane.
Am i right in this regard or there is some problem in my understanding

 

[BF9000]

Antenna

I have not used this type, so I cannot quantify the loss of signal quality with the connector. My guess is that it will likely not be noticeable. I am only saying it is less than optimal, because I am assuming the tab will cause minor impedance matching issues. However, this should not cause a big problem as it is only a short distance. In general, connectors will not be the source of problems at this frequency.

You cannot have the screw short the antenna to the ground plane. To solve this problem you should be able to manually route an area out of the copper to isolate the connection or you could try using a paper washer where the screw would contact the ground plane. The antenna should be connected to the ANT pin and nothing else.

 

[FRIED]

ground plane underneath connecting this antenna in this way through a screw will short circuit the antenna connection to the ground plane.

Remove some groundplane to clear the screw