INVERTED F ANTENNA DIMENSION MISMATCH

Anubhav Gupta

Other Parts Discussed in Thread: CC2531, CC2591, CC2530, CC2500

Dear TI,

We at Sumona consulting are developing a ZIGBEE based home automation system .we are in the design stages of developing a usb dongle using CC2531,CC2591 and Inverted F Antenna.

For designing the inverted F antenna we are using TI document DN0007 and for cross reference we are using the CC2530_CC2591_EM gerbers (SWRC171).while going through both the documents we found out that; the DN0007 says that total length (L1) should be 25.58mm.but the CC2530_CC2591_EM gerbers shows 25.98mm total length.

second point is all the dimensions in the CC2530_CC2591_EM gerbers is 0.2mm lesser than the dimensions mentioned in DN0007.please clarify and suggest us which document to follow.

Please find the attached documents

regards

Sumona

over 14 years ago

0 Jim Noxon over 14 years ago

TI__Genius 14940 points

Sumona,

DN007 identifies the PCB thickness to be 1mm while the readme.txt file in the CC2530_CC2591_RD package indicates the PCB thickness is 1.6mm. These differences can cause deltas in geometry as the electrical length of the conductive components will change with differing PCB thickness. See application note AN068 for additional explanation. It is located here

http://focus.ti.com/lit/an/swra236a/swra236a.pdf

Regaards,

Jim

0 Anubhav Gupta over 14 years ago in reply to Jim Noxon

Expert 1130 points

dear jim,

thank you for the input.it was very helpful

regards

sumona

0 Tiago Gomes over 13 years ago in reply to Anubhav Gupta

Prodigy 230 points

HI,

According to my experience, I must also say that sometimes, while copying from gerber files, you must take into account the thickness of the segment that designs the polygon. I mean, if you have a square from 0,0 to 10,10 with the lines with 1mm thickness, if you use the measurement tool to measure the length of the polygon, the total length will be 10mm plus the 1mm of the segment.

Cheers

0 Chatto over 13 years ago in reply to Tiago Gomes

TI__Genius 12545 points

That is correct. You want to use the precise measurements for the antenna. though one can compensate for mismatch by adding shunt and series elements to the antenna feed point

0 gianfranco piedilato over 11 years ago in reply to Chatto

Prodigy 110 points

Hi,

I have a problem with review a board wireless(cc2500). I measured the dimension of antenna and it isn't match with dimensions indicate in document of texas Application Note AN043.

My board has problems in wireless transmission, at a distance of 7 meters it has a RSSI of -85: -90 DBI and an LQI varies from -50 to 94.
This problem may be due to wrong dimensions of the antenna and the wrong distance from the antenna to ground plane under antenna?

this are mismatch my dimensions

1)D3 is 0.857mm

2) D1 is 2.1mm

3)L6-D4=4.72399 instead of 4.4mm

4)D4 is 0.176001mm

attachment size mismatch in relation to the size of texas

Best Regards

0 Tiago Gomes over 11 years ago in reply to gianfranco piedilato

Prodigy 230 points

Hello,

Are you using original board from TI? or did you do your own design?

Cheers,

0 gianfranco piedilato over 11 years ago in reply to Tiago Gomes

Prodigy 110 points

Hi, I connect my design system embeded to the board texas and tested with smart rf Best Regards

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INVERTED F ANTENNA DIMENSION MISMATCH