  We demonstrate a low loss, chip-level frequency multiplexing scheme for
readout of scaled-up spin qubit devices. By integrating separate bias tees and
resonator circuits on-chip for each readout channel, we realize dispersive
gate-sensing in combination with charge detection based on two rf quantum point
contacts (rf-QPCs). We apply this approach to perform multiplexed readout of a
double quantum dot in the few-electron regime, and further demonstrate
operation of a 10-channel multiplexing device. Limitations for scaling spin
qubit readout to large numbers of multiplexed channels is discussed.
