A wideband integrated optic heterodyning device that utilizes simultaneously a wideband acousto‐optic (AO) Bragg cell and a wide‐angle electro‐optic (EO) Bragg grating lens has been realized, for the first time, in aY‐cut LiNbO3waveguide 1×8×20 mm3in size. The device has demonstrated a bandwidth of 240 MHz centered at 350 MHz and a single‐tone instantaneous and two‐tone third‐order spurious‐free dynamic ranges of 44.6 and 36.0 dB, respectively, at the optical wavelength of 0.6328 &mgr;m. The device suggests a new and simple architecture for wideband integrated optic interferometric rf spectrum analyzers.