An electronic device may be provided with wireless circuitry and control circuitry. The wireless circuitry may communicate using a 5G New Radio (NR) protocol. The wireless circuitry may have multiple bandwidth part configurations. The control circuitry may place the wireless circuitry in a first bandwidth part configuration where a first bandwidth part of a first component carrier is active and a second bandwidth part of a second component carrier is inactive. The control circuitry may switch the wireless circuitry from the first bandwidth part configuration to a second bandwidth part configuration in which the first bandwidth part is inactive and the second bandwidth part is active. The first and second component carriers may be intra-band contiguous, intra-band non-contiguous, or inter-band. The control circuitry may switch the wireless circuitry into other configurations for covering other bandwidth parts of any desired component carriers in any desired bands.