ST25RU3993-EVAL T2 20 dB Dir Coupler，DC1722J5020AHF frequency is 1700MHz-2300MHz，but T4 DC0710J5010AHF 10 dB Dir Coupler,frequency is 700MHz-1000MHz,Why is it designed like this?

[军胡.1765]

[Bart Herse]

Hello,

please take a look at the wideband performance charts in the datasheets of the both components.

• Compare the return loss for the input and the direct port.
• Compare the insertion loss and the transmission loss.

It appears that the 1.7 GHz version has lower values and therefore a better performance.

Coupling and directivity are not so much of a concern at this point.

Cheers,

B