Demonstration of Low-Loss and Miniaturized Terahertz Radial Waveguide Power Divider/Combiner

A G-band 16-way power divider/combiner (PDC) based on a radial waveguide structure is designed, fabricated, and experimentally validated in this article. The PDC consists of a rectangular TE10 to circular TE01 mode converter and a radial divider, and micro-machining and micro-electroforming processes are employed to ensure high structural accuracy and fabrication consistency. The cold test, including single-port and back-to-back measurements, is conducted, focusing on S-parameters and amplitudephase uniformity. The results indicate that within 210230 GHz, the S11 is better than -13 dB and S21 is better than -1 dB. For the total of 16 channels, the root mean square (rms) amplitude is less than 1 dB, and the rms phase is less than 5.2∘, demonstrating excellent amplitude and phase consistency. To evaluate its performance, a hot test by using a traveling-wave tube (TWT) is performed, and the tested insert losses of 1.1 dB are obtained at the frequency of 220 GHz. In addition, the fabricated PDC exhibits a regular hexadecagonal external contour, defined by a dimension of Φ81.6 ×δ24.5 mm. Characterized by compact, low-loss, and miniaturized longitudinal length as well as excellent power-handling capability, the PDC is well-suited for power dividing and combining by solid-state or vacuum electronic devices, thereby supporting the development of high-efficiency and high-power terahertz (THz) sources.