LAUNCHXL-CC3235S: Continuous transmission at the same output level in test mode

Danilo A.

Hi Team,

May I ask your help regarding our customer's inquiry below.

I used the test mode and sent continuously for over an hour. At this time, the transmission power suddenly increased by 1 dB. Is there a function to automatically change such transmission output? The setting at this time is Transmission Mode: Continuous Channel: 40 (5200MHz) Rate: 24Mbps (OFDM) DATA Pattern: PN23 802.11b Preamble: Long CCA Threshhold: -68dBm Amount: 0 Size: 1400 Power: 0 I want to do continuous transmission at the same output level in test mode. Please tell me how to achieve it.

Regards,

Danilo

over 2 years ago

0 Jesse Baker over 2 years ago

TI__Expert 6145 points

Hi Danilo,

Based on the description above, this is what the RadioTool GUI should look like:

Is that correct?

Is the customer using the most recent version of the Radio Tool (v1.0.3.19)?

Best regards,

Jesse

0 Jesse Baker over 2 years ago

TI__Expert 6145 points

Also, what is the purpose of this test? As mentioned in the Radio Tool User's Guide Section 7.2, Continuous mode should only be used for emission certification. Packetized mode is generally used for RF evaluation. Perhaps Packetized mode would be more appropriate?

Best regards,

Jesse

0 Hiroshi Kamata over 2 years ago in reply to Jesse Baker

Prodigy 20 points

The settings are correct.

0 Hiroshi Kamata over 2 years ago in reply to Jesse Baker

Prodigy 20 points

This test is used for emission certification.

0 Jesse Baker over 2 years ago in reply to Hiroshi Kamata

TI__Expert 6145 points

Hi Kamata-san,

You are likely seeing a change in the Tx power due to the internal power amplifier heating up from running in continuous mode over an extended period of time.

You can use packetized mode for emissions tests as well, and this way you can have control of the duty cycle of the transmission of the packets. By reducing the duty cycle to 30%, you can ensure that the power amplifier will not overheat.

Please see Section 2.4.2 Duty Cycle for Measurement of Tx Parameters of the CE Compliance Test Procedure for TI’s Wi-Fi Devices for steps to configure.

You can check the duty cycle by putting the spectrum analyzer in zero span (time domain) and adjust the radio tool parameters, "delay" and "size" (packet length) as needed.

Best regards,

Jesse

Wi-Fi

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LAUNCHXL-CC3235S: Continuous transmission at the same output level in test mode