Wireless circuitry, comprising: a first switch having a plurality of first switch terminals and having an additional terminal (T') to which a selected one of the plurality of first switch terminals is connected; a second switch having a plurality of second switch terminals and having an additional terminal (T') to which a selected one of the plurality of second switch terminals is connected; an antenna; a diplexer having a first port that is coupled to the additional terminal (T') of the first switch, a second port that is coupled to the additional terminal (T') of the second switch, and a third port that is coupled to the antenna; a first set of radio-frequency transmitters that operate in a first set of communications bands; and a second set of radio-frequency transmitters that operate in a second set of communications bands; wherein: each of the first switch terminals is coupled to a respective one of the radio-frequency transmitters in the first set of radio-frequency transmitters; each of the second switch terminals is coupled to a respective one of the radio-frequency transmitters in the second set of radio-frequency transmitters; the diplexer is configured to block signal harmonics of signals transmitted by the first and second sets of radio-frequency transmitters, wherein the signal harmonics are generated by the first and second switches; characterized in that: the diplexer includes a low pass filter and a band pass filter; the first set of radio-frequency transmitters includes a first Long Term Evolution cellular telephone transmitter that operates in a first LTE band; and the second set of radio-frequency transmitters includes a second Long Term Evolution cellular telephone transmitter operating in a second LTE band, the second LTE band being at a higher frequency than the first LTE band; wherein at least one of the first and second LTE bands have harmonics that fall within an IEEE 802.11 band at 2.4 GHz or 5 GHz and/or a satellite navigation system band, and the diplexer prevents the harmonics from reaching the antenna. a first switch having a plurality of first switch terminals and having an additional terminal (T') to which a selected one of the plurality of first switch terminals is connected; a second switch having a plurality of second switch terminals and having an additional terminal (T') to which a selected one of the plurality of second switch terminals is connected; an antenna; a diplexer having a first port that is coupled to the additional terminal (T') of the first switch, a second port that is coupled to the additional terminal (T') of the second switch, and a third port that is coupled to the antenna; a first set of radio-frequency transmitters that operate in a first set of communications bands; and a second set of radio-frequency transmitters that operate in a second set of communications bands; each of the first switch terminals is coupled to a respective one of the radio-frequency transmitters in the first set of radio-frequency transmitters; each of the second switch terminals is coupled to a respective one of the radio-frequency transmitters in the second set of radio-frequency transmitters; the diplexer is configured to block signal harmonics of signals transmitted by the first and second sets of radio-frequency transmitters, wherein the signal harmonics are generated by the first and second switches; characterized in that: the diplexer includes a low pass filter and a band pass filter; the first set of radio-frequency transmitters includes a first Long Term Evolution cellular telephone transmitter that operates in a first LTE band; and the second set of radio-frequency transmitters includes a second Long Term Evolution cellular telephone transmitter operating in a second LTE band, the second LTE band being at a higher frequency than the first LTE band; wherein at least one of the first and second LTE bands have harmonics that fall within an IEEE 802.11 band at 2.4 GHz or 5 GHz and/or a satellite navigation system band, and the diplexer prevents the harmonics from reaching the antenna. the diplexer includes a low pass filter and a band pass filter; the first set of radio-frequency transmitters includes a first Long Term Evolution cellular telephone transmitter that operates in a first LTE band; and the second set of radio-frequency transmitters includes a second Long Term Evolution cellular telephone transmitter operating in a second LTE band, the second LTE band being at a higher frequency than the first LTE band; wherein at least one of the first and second LTE bands have harmonics that fall within an IEEE 802.11 band at 2.4 GHz or 5 GHz and/or a satellite navigation system band, and the diplexer prevents the harmonics from reaching the antenna.