Thin Film Enabled Engineered Substrate for Miniaturized Antennas with Improved Bandwidth

This paper presents a novel engineered substrate enabled by patterned Permalloy (Ni80Fe20, Py) thin films for the development of miniaturized antenna with improved bandwidth. The perspective substrate is implemented with multiple layers of 100 nm thick Py thin film patterns embedded on arbitrary microwave substrate, and each Py layer consists of an array of Py patterns with a dimension of $15\mu\mathrm{m}\times 40\mu\mathrm{m}$ and $5\ \mu\mathrm{m}$ gaps among them to suppress the magnetic loss. An equivalent permeability of 2.398 is achieved for engineered substrate embedding with 10 layers of Py thin films. A simple patch antenna has been implemented on the engineered substrate to demonstrate the efficacy of designing miniaturized antenna with improved bandwidth, compared to antenna on regular substrate, results show that the developed antenna on engineered substrate has a size reduction of 47.3% and an improved bandwidth of 49.6%.