Closed-Form Expressions for the Equivalent Circuit Model of Square-Waveguide T-Junctions and Its Application in Ortho-Mode Transducer Design

Mode Filters for Oversized Rectangular Waveguides: A Modal Approach

“…The last expressions are also used in the approximate coupling coefficient (29) of Section V, the derivation of which is briefly outlined in the following. We consider a current source , located in the volume of an infinitely long waveguide with cross section on , which excites a set of TE and TM modes.…”

“…Compared to (38), (41) only differs in the longitudinal dependence of with respect to : the former is the unperturbed magnetic field in the unslotted waveguide where no reflected wave is present. This difference results in the correction factor that multiplies in (29). After an internship with Telespazio and another with Thales Alenia Space, in 2009, he began a three-year scholarship for scientific training across European laboratories on RF systems for nuclear fusion.…”

“…[19]- [23], and has been recently combined with other advanced methods [24], [25]. The resonator technique provides a powerful tool to analyze right-angle waveguide corners as in T-junctions [18], [26], directional couplers [27], diplexers [28], ortho-mode transducers [29], etc.…”

Synthesis of single- and dual-band short-circuited waveguide orthomode transducers

“…However, no physical implementation was presented due to the lack of a proper circuit model. In [7], a dual-mode equivalent circuit model of the simple square waveguide Tjunctions was developed as a building block of the shortcircuited waveguide OMT, and then the classic circuit analysis method was employed in the OMT design. In this paper, an improved equivalent circuit model of the slot-coupled square waveguide T-junction is proposed as a building block, which is initially divided into two separate subnetworks by polarization.…”

“…Compared with [7], the improvements lie in two aspects: (i) the size of the coupling slot in the square waveguide T-junction is adjustable to control the coupling between the main and branch waveguides; (ii) proper circuit elements are employed in the improved model to better reveal the physical insight into the structure than the one in [7]. The coupling slot is modeled as an impedance inverter, the junction effect is accounted for through a shunt susceptance, and additional transmission lines are employed to compensate the phase shift.…”