Dual Band Radio Frequency Detector Based on the Simultaneous Excitation of Free and Reference Layer in a Magnetic Tunnel Junction

We demonstrate an energy efficient method of radio frequency (RF) detection for two bands (<inline-formula> <tex-math notation="LaTeX">${S}+{C}$ </tex-math></inline-formula> and <inline-formula> <tex-math notation="LaTeX">${X}-$ </tex-math></inline-formula> band) using a magnetic tunnel junction-based nanopillar. For a carefully chosen geometry, two modes are simultaneously excited with the opposite sign of rectification voltage, enabling microwave band identification in a single device without the requirement for a DC bias. Micromagnetic simulations demonstrate that the opposite sign of rectification voltage is due to the simultaneous excitation of the free and reference layers. A method of enhancement of bandwidth in the <inline-formula> <tex-math notation="LaTeX">${X}-$ </tex-math></inline-formula>band is discussed.