A single electron transistor charge sensor in strong rf fields

We measure the charge sensitivity, Se, of a single electron transistor (SET) in the presence of strong (Vrf ∼ e/Cg) spurious radio frequency (rf) signals at frequencies up to 50 MHz, where Cg is the gate capacitance. Although Se appears to degrade when exposed to Vrf, we find that broadening of conduction peaks is largely due to the measurement technique and show that Se is maintained even with strong Vrf present. We show cancellation of a known Vrf signal at 1 MHz, demonstrating that a stable bias point in the presence of rf signals is possible.