Image Dielectric Guides-Based Crossover for Millimeter-Wave Applications

The low-loss attribute of the image dielectric guide (IDG) at the mm-wave range is exploited in this research by presenting a crossover based on IDG for the first time. In the proposed crossover, two IDGs are employed for efficiently crossing the two independent radio frequency (RF) channels. The isolation of the two channels has been significantly improved by increasing the widths of the IDGs in the region approaching the channel intersection. Due to the very simple structure, the proposed crossover is fabricated just with a 3-D printer and copper tapes. Results exhibit that with a simulated insertion loss (
$S_{21}$
and
$S_{43}$
) of 1.6 dB, the proposed crossover exhibits an ultrawide bandwidth of 17.51 GHz (27–44.51 GHz). Over this bandwidth, the isolation between the two RF channels and the return loss of the ports are more than 20 dB. The group delay dispersion is very small compared to the other crossovers with a deviation of only 0.04 ns over the frequencies of operation. The wider bandwidth, simplest structure, improved isolation of channels over the entire bandwidth, and good impedance matching emphasize its use in millimeter-wave applications.