Design of ultra wideband 3dB coupler based on HTCC technology

To meet the urgent demand for broadband devices in practical engineering applications, this article introduces the design of a seventh order ultra wideband coupled strip line 3 dB coupler based on HTCC technology. The strip line structure and manufacturing process of the coupler are specifically explained, and its theoretical dimensions are calculated using corresponding design principles. Based on the theory of parallel coupling lines, a multi section coupler design theory is used to analyze the number of coupling sections. According to theoretical calculations and circuit simulations, a seven section coupling line is finally adopted, combined with the spatial structure above and below the coupling strip line, for modeling and simulation. The simulation results show that using this design of coupler, due to the high dielectric constant of HTCC, can shorten the length of the strip line and increase the bandwidth of the device, thereby achieving miniaturization and broadband of the coupler. The final size of the single coupler is $20 \text{mm} \times 15 \text{mm}$, and it has good performance in the $4-16 \text{GHz}$ frequency band.