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I’m simulating a Dielectric Resonator Antenna (DRA) using Barium Titanate (BaTiO‑) at 2.5 GHz. Which material properties, beyond permittivity, are critical to model accurately for realistic performance prediction?

My initial design uses the high permittivity (ε_r ~ 80-200) of BaTiO? to shrink the DRA size. But I know its properties are frequency-dependent and can vary with temperature and fabrication process. For a reliable simulation at 2.5 GHz, what specific material data should I be sourcing? Is the loss tangent (tan δ) the next most critical factor, or do I need to account for its non-linear behavior, temperature coefficient, and possible porosity if I'm using a sintered ceramic? How do these factors ultimately impact radiation efficiency and resonant frequency shift in a real prototype?

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By Mehvish Answered 3 months ago

For a practical BaTiO? DRA, sourcing accurate frequency-dependent data at 2.5 GHz is paramount. The high loss tangent (tan δ), often between 0.001 and 0.01 for commercial grades, will be your primary limiter for radiation efficiency—model this correctly. You must also account for temperature stability; BaTiO? has a high τε, meaning its resonant frequency will drift with ambient temperature changes. For simulation, use a conservative, mid-range ε_r value from a datasheet (e.g., ε_r=100) and the associated tan δ. Importantly, actual sintered ceramic will have slightly lower ε_r and higher loss than pure, theoretical values due to porosity and impurities. I always prototype with the exact material I'll use in production and measure its properties with a resonant cavity to back-correct my model.

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