Do-It-Yourself Sheet-Metal Open TEM Cell

This paper presents an improved open transverse electromagnetic (TEM) cell for pre-compliance testing. The design shows a 300 mm septum height and works over CISPR Bands C and D (from 30 MHz to 1 GHz). The improvement lies in its do-it-yourself construction, enabling in-house manufacturing using laser-cut, bendable sheet metals with rectangular slots removed to ease bending. The resulting structure is cost-effective and mechanically robust. 3D-printed supports extending only between the septum and the upper conductor improve the accessibility to the test volume. The design is tested experimentally (minimum return loss of 11.5 dB), and its reproducibility is validated over four independently assembled samples.