Transmission zero engineering in lateral double‐barrier resonant tunneling devices is investigated. We show that, by inserting a resonant cavity in the quantum well region of a lateral double‐barrier resonant tunneling structure and engineering the placement of transmission zero‐pole pairs, the current peak‐to‐valley ratio of the device can be drastically improved at low temperature. An advantage of this structure also is that a lower peak voltage can be obtained compared to the corresponding lateral double‐barrier resonant tunneling device. ©1996 American Institute of Physics.