Wireless certification about CY8C4248LQI-BL583

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TaTa_2447651
Level 3
Level 3
First solution authored 25 replies posted 10 replies posted

無線認証に関して質問です。

PSoC4(CY8C4248LQI-BL583)を使用して自社の製品開発を行っています。

日本の無線認証(工事設計認証)試験において問題が発生しているため質問させてください。

マイコンからの無線出力をアンテナの手前で直接ケーブルに接続し、2.440GHzの変調波と無変調波

を測定したところ添付のような波形が計測されました。変調波のほうは問題なさそうですが、無変調波

のほうは設定した周波数以外に隣のチャンネルの周波数も一緒に観測されており、変調が掛かっている

ような出力となっています。

製品の構成としてはCY8C4248LQI-BL583を使用しアンテナは自社開発のものとなっています。

また、試験に使用しているファームウェアは、Cypress社提供の試験用ファームを使用しています。

2点ほど質問があるのですが、

・過去にこのような現象がありましたでしょうか?あった場合、対策方法を教えて頂けますか?

・無線試験用のファームで最新のものをご提供いただけないでしょうか?

よろしくお願いいたします。

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This is a question about wireless certification.

We are developing a product using PSoC4 (CY8C4248LQI-BL583) and have a problem with the Japanese wireless certification test.

The wireless output from the MCU was directly connected to the cable before the antenna and a 2.440 GHz modulated wave and unmodulated waves were measured as shown in the attachment.

There seem to be no issues with the modulated signal, but the unmodulated wave has the frequency of the adjacent channel in

addition to the set frequency, and the output appears to be as if modulation is applied.

The product configuration uses CY8C4248LQI-BL583 and the antenna is developed in-house.

The firmware used for testing uses the testing firmware provided by Cypress.

1. Has this phenomenon been observed the past? If so, what countermeasures were taken?

2. Could you provide the latest wireless test firmware?

Thank you

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1 Solution

Hi Takeuchi-san,

In packet transmission mode, we open the PLL loop to enable direct modulation through VCO. The initial firmware did not close the loop for carrier wave transmission. When open, the output frequency is maintained by a small capacitor, but as it discharges, the frequency would drift. The fix was to close the loop for Carrier Wave mode transmission.

By, general firmware, we guess you mean the standard BLE component. The regulatory test firmware also uses the BLE component only for test modes supported by the component. The Carrier Wave output is not supported by the component. So, you needs to use the function we have defined in the test firmware for the carrier wave output.

Thanks and regards

Ganesh

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