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The integrated planar technique has been considered as a reliable candidate for low-cost mass production of millimeter-wave circuits and systems. This paper presents new concepts that allow for a complete integration of planar circuits and waveguide filters synthesized on a single substrate by means of metallized post (or via-hole) arrays. Analysis of the synthesized integrated waveguide and design criteria are presented for the post pitch and diameter. A filter design method derived from a synthesis technique using inductive post is presented. An experimental three-pole Chebyshev filter having 1-dB insertion loss and return loss better than 17 dB is demonstrated. Integrating such planar and nonplanar circuits on a substrate can significantly reduce size, weight, and cost, and greatly enhance manufacturing repeatability and reliability.Index Terms-Hybrid integrated circuits, millimeter-wave filters, substrate integrated waveguide.

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This paper presents the results of a bibliometric analysis of the knowledge domains resilience, vulnerability and adaptation within the research activities on human dimensions of global environmental change. We analyzed how 2286 publications between 1967 and 2005 are related in terms of co-authorship relations, and citation relations.The number of publications in the three knowledge domains increased rapidly between 1995 and 2005. However, the resilience knowledge domain is only weakly connected with the other two domains in terms of co-authorships and citations. The resilience knowledge domain has a background in ecology and mathematics with a focus on theoretical models, while the vulnerability and adaptation knowledge domains have a background in geography and natural hazards research with a focus on case studies and climate change research. There is an increasing number of cross citations and papers classified in multiple knowledge domains. This seems to indicate an increasing integration of the different knowledge domains. r

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and the reflection losses are better than 12 dB throughout the pass band for both cases.In addition, a two-cell CRLH filter is designed at a center frequency of 1.8 GHz and a fractional bandwidth of 110% following the procedure expanded in [10]. The design values of the CRLH unit cell are C R ¼ 0.5 pF, L R ¼ 1.6 nH, C L ¼ 2.2 pF, and L L ¼ 4.3 nH. This gives a À3 dB lower cutoff of f 1 ¼ 0.8 GHz and an upper cutoff f 2 ¼ 2.8 GHz. The circuit was implemented using standard surface mount devices (SMD).To implement the notch filter, the ENZ tunnel is connected to the CRLH filter as shown in Figure 5(b). The CRLH filter along the tunnel structure is simulated using [8]. Figure 7 shows the simulated and experimental S 21 and S 11 responses. The simulated notch frequency is read at 1.85 GHz with a reflection loss of about 26 dB and an insertion loss of 1.3 dB. For the experimental response the return loss is 18 dB at the center frequency (1.94 GHz) and an insertion loss of 2 dB is recorded. The experimental 3 dB pass band is 2.14 GHz (from 1.15 to 3.29 GHz). There is a slight frequency shift of 0.2 GHz to lower frequencies in the experiment compared with the simulation. This frequency shift is thought to be because of parasitic effects of the SMD components, the effects of the vias to ground and the mismatch between the microstrip line width and the width of the SMD components. However, good agreement is observed between simulation and experiment. CONCLUSIONSA miniaturized HM substrate integrated ENZ tunnel has been demonstrated. It was shown that this structure allows only one frequency to tunnel through because of the static-like behavior when epsilon is near zero. Subsequently, the tunnel was connected to a CRLH filter in a decoupling mode to reject unwanted frequencies. Good agreement is seen between experimental and simulated results. ABSTRACT: In this study, a dielectric corrugated antenna, as being a feed horn antenna of the reflector antenna for satellite communication applications, is analyzed. The structure consists of a conical dielectric corrugated antenna terminated with a conductor hyperbolic (convex) plate. The antenna system provides a Gaussian beam within wide frequency bandwidth with its dielectric structure. The antenna is simulated and tested for its return loss and radiation performances, and the satisfactory results are obtained for C band satellite communication applications.

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