The emission properties of an electron in a double quantum well driven by ultrashort electromagnetic half-cycle pulses are studied. By numerically solving the corresponding time-dependent Schrödinger equation we show that the emission spectrum can be designed by appropriately choosing the parameters of the pulses. Low-frequency generation (LFG) is observed, and conditions for intense LFG and strong induced localization are found. The effects of absence of generalized parity of the Floquet modes on the emission spectrum are discussed. Simple relations for determining the values of the pulse parameters for controlling the localization process and the emission properties are found from an analytical approximation.