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We explore an emerging device concept based on exchange bias used in conjunction with an antidot geometry to fine tune ferromagnetic resonances. Planar cavity ferromagnetic resonance is used to study the microwave response of NiO/NiFe bilayers with antidot structuring. A large frequency asymmetry with respect to an applied magnetic field is found across a broad field range whose underlying cause is linked to the distribution of magnetic poles at the antidot surfaces. This distribution is found to be particularly sensitive to the effects of exchange bias, and robust in regards to the quality of the antidot geometry. The template based antidot geometry we study offers advantages for practical device construction, and we show that it is suitable for broadband absorption and filtering applications, allowing tunable anisotropies via interface engineering.

In this paper, we will investigate a metal- insulator-semiconductor (MIS) like InGaAs/GaAs doped-channel structure both in theoretical analysis and experiment. First, a charge control model is employed to simulate the basic electronic properties of the doped-channel field-effect transistor (FET). Then, a practical device is fabricated and processed. From the results, we can find that the device shows good transistor characteristics. A high breakdown voltage of 17.4 V, a maximum drain saturation, current of 930 mA/mm, a maximum transconductance of 235 mS/mm, and a very broad gate voltage swing larger than 3V with the transconductance higher than 200mS/mm are obtained for a 2x100 um2 gate-dimension FET. From the comparison, we find that the experiments are in good agreement with the theoretical simulations. The, performances provide a promise of the proposed device to be a good candidate for practical circuit applications.