The balun of nrf51822

[KING JAMES]

I simulated the balun of nrf51822 accroding to the referenced design of nrf51822 on the official website.
However,it showed the differential phase of the balun was not 180 degrees.
Please help me to find a solution,thanks.

[KING JAMES]

[ketiljo]

When you simulate the phase difference on the pins, you will find that this is not 180 degrees. Inside the radio front end, on the PA output in TX mode and on the input of the LNA in RX mode, you will find that the phase difference is close to 180 degrees. 

[KING JAMES]

Please confirm it to you again.Is the impedance from point A  to NRF51822 50 ohms, or the load at point A 50 ohms?

[ketiljo]

The impedance, looking from the matching network, at A, into the load is 50 ohm. It's _not_ 50 ohm seen from the load into A.

[KING JAMES]

Why the parameters of QFAC are different ?

[KING JAMES]

[ketiljo]

The length of the bonding wires are difference due to the larger die of the QFAC (more memory), meaning that the QFAC has shorter bonding wires and hence less series inductance.