A communication unit, such as a radar unit (500) includes a plurality of cascaded millimetre wave, mmW, transceiver, TRx, circuit, each comprising at least one phase shift circuit (616) and each coupled to respective antennas; and a signal processor circuit (552) operably coupled to the plurality of cascaded mmW TRx circuits and configured to process transmit and receive signals of the plurality of cascaded mmW TRx circuits. The radar unit (500) further comprises: a first TRx circuit (320) of the plurality of cascaded mmW TRx circuits being configured to wirelessly transmit (360) a signal to a second TRx circuit (322) via a respective antenna; a localization processing circuit (580) operably coupled to at least one of the first TRx circuit (320) and second TRx circuit (322) and configured to wirelessly determine a distance relationship (350) between at least one antenna coupled to the first TRx circuit (320) and at least one antenna coupled to the second TRx circuit (322); and a phase control unit (602), operably coupled to the localization processing circuit (570) and configured to adjust at least one phase shifter (616) in response to the wirelessly determined distance relationship.