Why is the linewidth broadened ? Phasenoise is the parameter that any engineer will ask you to provide in order to evaluate the performance and to define possible applications for an oscillator. From theory [Kim, Slavin], phase noise is a major contribution to linewidth broadening and linewidth is thus a good first indicator for phase […]

What are typical linewidths ? Besides output power (for which good strategies exist to reach the required specifications), linewidth is an important issue and determines basically the type of applications where STOs can compete. The linewidth measured in the literature for a large variety of oscillators varies from about 1 GHz to 1 MHz (with […]

What are the requirements ? Integration of STOs into conventional RF circuitry means that the STO has to meet certain specifications. The most important are output power and phasenoise. In this section we consider only the output power. In technical terms, the STO has to deliver 0dBm, for instance when its output is connected to […]

How to stabilize an ascillation around the energy maximum ? Why a perpendicular polarizer ? First experiments of spin torque driven excitations using an in-plane magnetized polarizer (in a standard spin valve structures) [Cornell, NIST] showed (i) that a non-zero external magnetic field is required to induce auto-oscillations and (ii) that the oscillation amplitude makes […]

What are the requirements? Integration of STOs into conventional RF circuitry means that the STO has to deliver 0dBm to drive for instance RF blocks such as a mixer. Using magnetic tunnel junction devices we have seen that the output signal can be enhanced to -40 dBm (see section on Spin Valves vs Tunnel Junctions). […]