Two layer LTCC substrate integrated to rectangular waveguide transition and its application for millimeter‐wave LTCC characterization

Abstract

In this letter, a new practical approach for designing a millimeter‐wave transition at 76.5 GHz from substrate integrated waveguide (SIW) line on two low temperature cofired ceramics (LTCC) layers to a rectangular waveguide is proposed. To the best of our knowledge, this is the first feasible planar solution to couple a top‐layer SIW exclusively. A very small probe is cut in both layers and inserted into a milled clearance in the metallic waveguide. Shrinkage tolerance is addressed in particular in our design procedure. In addition, multiple back‐to‐back transitions are milled into one fixture and applied to obtain the actual LTCC loss tangent and permittivity. The latter undergoes a strong dispersion. Fabricated circuits are optically analyzed and exhibit a higher shrinkage than expected. Simulation and measurement results show good performances in terms of reflection and transmission. With these features, the proposed solution is able to handle electrically large substrates of around 12λg. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2675–2679, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27167

Internal slot phase varying in traveling‐wave substrate‐integrated waveguide slot antennas and appropriate modeling

“…This is a frequently faced issue in millimeter-wave bands. Although these reflections are in a low range of approximately 215 dB [12], for N 5 4 the remaining amount at the end of the array is still significant. For comparison, the highest MC coefficients in the TWA, for example, b n , are in the same range as the reflections from the end, but their severe impact has been very well compensated in the design process, as seen in Figure 6.…”

“…Radiation pattern of fabricated circuit in transition plus fixture of . [Color figure can be viewed in the online issue, which is available at wileyonlinelibrary.com]…”

“…To prove the concept and feasibility, an antenna array circuit for the 77 GHz millimeter‐wave band has been fabricated, see Figure , and measured with a transition to waveguides and a mechanical fixture . The general circuit parameters are SIW width = 1.235 mm, height = 0.21 mm, ε r = 6.8, via radius = 0.075 mm, and pitch = 0.326 mm, with N = 4 slotted elements.…”

Broadband transition between substrate integrated waveguide and rectangular waveguide based on ridged steps

“…The in-line transitions were realized by probes, such as radial probe [9], fin line probe [10], substrate taper [11], and antipodal quasi-Yagi antenna probe [12], inserting into smooth height-tapered waveguide or normal waveguide. In [13], two-step architecture was designed in RWG with a probe inserting into waveguide cylindrical hole.…”