I’m currently in the middle of commissioning a 20kW microwave tunnel kiln for a technical ceramics project. We’re seeing some weird fluctuations in the reflected power readings as the kiln hits the 800°C mark. My theory is that the dielectric shift in the alumina plates is throwing off our impedance matching faster than our current automated tuners can track.

I’ve been looking at the [Custom Industrial Microwave Equipment] from Pindom, specifically their 3-stub tuner assemblies. They mention that their triangular arrangement provides better mechanical stability in high-temp, high-vibration environments. Has anyone here actually benchmarked a 3-stub vs. a standard E-H tuner in a continuous production environment? I’m specifically worried about the 'Mode Suppression' claims—we need a very clean TE₁₀ mode to avoid cracking the plates. If their [Microwave Accessories] can actually maintain isolation and matching under these loads, it might save us from redesigning the entire cavity. Any thoughts on their WR340 or WR430 hardware quality?

 

Before you redesign the kiln, you'll have to carry out some fundamental research