> 4 | Antenna Interface

> The RF interface has an impedance of 50 Ω. TC65 is capable of sustaining a total mismatch at the antenna connector without any damage, even when transmitting at maximum RF power.
> The external antenna must be matched properly to achieve best performance regarding radiated power, DC-power consumption, modulation accuracy and harmonic suppression. Antenna matching networks are not included on the TC65 PCB and should be placed in the host application.
> Regarding the return loss TC65 provides the following values in the active band:

> Table 19: | Return loss in the active band

> State of module | Return loss of module | Recommended return loss of application
> Receive | > 8dB | > 12dB
> Transmit | not applicable | > 12dB

> The connection of the antenna or other equipment must be decoupled from DC voltage. This is necessary because the antenna connector is DC coupled to ground via an inductor for ESD protection.