Low power microwave bubble generator

In this paper we discuss experimental results, dwelling particularly on the frequency sensitivity of the minimum microwave field necessary for bubble generation. A broad-band coplanar waveguide circuit was developed to provide leveled microwave power to a 4 μm by 4 μm shorting region producing highly local and intense microwave magnetic fields. In the samples employed, extremely low microwave fields generate bubbles, implying power dissipation in the μW range. We feel that when the system is scaled up to the large anisotropy field values of conventional magnetic bubble devices, the power dissipation will increase dramatically. However, our experimentation has revealed that microwave pulses shorter than 25 nsec may be used to generate bubbles. Due to the anticipated low average power dissipation, such a device may have an advantage over conventional bubble generators.