High linearity antenna swapping circuitry

1. Radio frequency (RF) front end circuitry comprising:

transceiver switching circuitry;

antenna swapping circuitry comprising:

a first pole and a second pole;

a first throw and a second throw; and

a first switching element coupled between the first pole and the first throw, a second switching element coupled between the first pole and the second throw, a third switching element coupled between the second pole and the first throw, and a fourth switching element coupled between the second pole and the second throw; and

multiplexer circuitry coupled between the transceiver switching circuitry and the antenna swapping circuitry; and

switch control circuitry coupled to the transceiver switching circuitry and the antenna swapping circuitry and configured to:

in a first low-band transmit mode, provide a primary low-band transmit signal at the first pole of the antenna swapping circuitry via the transceiver switching circuitry and forward the primary low-band transmit signal to the first throw via the first switching element in the antenna swapping circuitry; and

in a second low-band transmit mode, provide a primary low-band transmit signal at the second pole of the antenna swapping circuitry via the transceiver switching circuitry and forward the primary low-band transmit signal to the second throw via the fourth switching element in the antenna swapping circuitry.

2. The RF front end circuitry of claim 1 further comprising a primary antenna coupled to the first throw and a secondary antenna coupled to the second throw.

3. The RF front end circuitry of claim 1 wherein a linearity of the first switching element and the fourth switching element at low-band frequencies is greater in a closed state than in an open state, and a linearity of the second switching element and the third switching element at low-band frequencies is greater in a closed state than in an open state.

4. The RF front end circuitry of claim 3 wherein a third harmonic distortion generated by the first switching element and the fourth switching element at low-band frequencies is 6 dB to 12 dB greater in the open state than in the closed state.

5. The RF front end circuitry of claim 4 wherein a third harmonic distortion generated by the second switching element and the third switching element at low-band frequencies is 6 dB to 12 dB greater in the closed state than in the open state.

6. The RF front end circuitry of claim 5 wherein each of the first switching element, the second switching element, the third switching element, and the fourth switching element include a plurality of switching devices, each of the switching devices having a particular channel width.

7. The RF front end circuitry of claim 6 wherein the channel width of the plurality of switching devices in each of the first switching element and the fourth switching element is greater than the channel width of the plurality of switching devices in each of the second switching element and the fourth switching element.

8. The RF front end circuitry of claim 7 wherein the plurality of switching devices in each of the second switching element and the third switching element is greater than the plurality of switching devices in each of the first switching element and the fourth switching element.

9. The RF front end circuitry of claim 1 wherein the switch control circuitry is further configured to:

in a first mid/high-band transmit mode, provide a mid/high-band transmit signal at the first pole of the antenna swapping circuitry via the transceiver switching circuitry and forward the primary mid/high-band transmit signal to the first throw via the first switching element in the antenna swapping circuitry; and

in a second mid/high-band transmit mode, provide a mid/high-band transmit signal at the first pole of the antenna swapping circuitry via the transceiver switching circuitry and forward the primary mid/high-band transmit signal to the second throw via the second switching element.

10. The RF front end circuitry of claim 9 wherein a linearity of the first switching element and the fourth switching element at low-band frequencies is greater in a closed state than in an open state, and a linearity of the second switching element and the third switching element at low-band frequencies is greater in a closed state than in an open state.

11. The RF front end circuitry of claim 10 wherein a third harmonic distortion generated by the first switching element and the fourth switching element at low-band frequencies is 6 dB to 12 dB greater in the open state than in the closed state.

12. The RF front end circuitry of claim 11 wherein a third harmonic distortion generated by the second switching element and the third switching element at low-band frequencies is 6 dB to 12 dB greater in the closed state than in the open state.

13. The RF front end circuitry of claim 12 wherein a channel width of the plurality of switching devices in each of the first switching element and the fourth switching element is greater than a channel width of a plurality of switching devices in each of the second switching element and the fourth switching element.

14. The RF front end circuitry of claim 13 wherein the plurality of switching devices in each of the second switching element and the third switching element is greater than the plurality of switching devices in each of the first switching element and the fourth switching element.