CC2640R2F: AOA reference design antenna issue

jiangbin zhu

Part Number: CC2640R2F

My question is about AOA demo board design.

1. I am not sure the function of below meander line(please refer to the red arrow pointed ).

2. I did simulation with reference design antenna(balun and bipolar antenna), notice that the arm lenght might not be the optimized one, the total radiation efficiency(radiation power/incident power) is low. My question is: is arm length limited by antenna gap? Under current condition, how much is the radiation efficiency? Any document we can refer to?

over 5 years ago

0 R.M over 5 years ago

TI__Genius 9215 points

Hi,

Your images do not show in your post, can you please try to post again with the images?

Best Regards,
R.M

0 jiangbin zhu over 5 years ago in reply to R.M

Prodigy 100 points

0 R.M over 5 years ago in reply to jiangbin zhu

TI__Genius 9215 points

Hi,

1. The function of the meander line is impedance matching for the balun.
2. The dipole antennas are made shorter on purpose to make it possible to place the antennas closer together. With these shorter antenna arms you sacrifice around 10 dB in efficiency.

Best Regards,
R.M

0 jiangbin zhu over 5 years ago in reply to R.M

Prodigy 100 points

Hi R.M

For the first question, meander line is impedance matching for balun. How we made it as I noticed that the wide of meander line is same as they go throuth the inner layer please refer to picture below.

or I made mistake they should be different wide?

0 R.M over 5 years ago in reply to jiangbin zhu

TI__Genius 9215 points

Hi,

The lines should have the same width.

Best Regards,
R.M

0 jiangbin zhu over 5 years ago in reply to R.M

Prodigy 100 points

Hi R.M

With same layer stack and same wide how can it acts as impedance match network? We can find a lot of meander line in paralleled devices such as DDR3, what is difference between them?

BRs

jiangbin

0 R.M over 5 years ago in reply to jiangbin zhu

TI__Genius 9215 points

Hi,

The meander line acts as a PCB meander coil (small inductor).
Meander lines in DDR3 designs are typically for length matching (same trace length on all parallel signals).

Best Regards,
R.M

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CC2640R2F: AOA reference design antenna issue