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This study presents a highly customisable bandpass filter based on standard printed circuit board (PCB) material and process. Such a filter utilises cascaded bandstop‐bandpass‐bandstop (BS‐BP‐BS) topology. There is one substrate integrated waveguide (SIW) coax resonator in each bandstop section, whereas there are three SIW coax resonators in the bandpass section. The coax resonators are built by SIW vias, and the resonant frequency of each resonator is determined by the lumped capacitors mounted on the top side of the filter. While the bandpass section of the filter provides a necessary passband response, the bandstop sections that cascade on both sides of the filter introduce an optional notch to the spectrum. Furthermore, with additional sets of plated‐through vias purposefully placed between resonators, reconfiguring the bandwidth of the passband is achievable through changing the lumped capacitors mounted on the bottom side of the vias of the filter. Measured results show centre frequency, notch frequency, and bandwidth are individually configurable, and such configurations are very intuitive and predictable. To the best of our knowledge, the proposed design is the first single layer PCB SIW coax filter deploying BS‐BP‐BS topology that has a configurable centre frequency, flexible 3‐dB bandwidth as well as predefine transmission zero.

BACKGROUND Nasogastric tube (NG) insertion is one of the essential clinical skills. Unfortunately, it’s a blind procedure, as one cannot directly visualize the tip of the NG during the insertion process. Thus, the most significant risk was malposition. Suppose blind insertion can be broken through in teaching strategies so that learners can see through the internal structure of the human body when performing technology. In that case, students can have better memory and comprehension and simultaneously provide real-time feedback, both of which are conducive to conceptualizing invasive surgical execution. OBJECTIVE A mobile-based interactive simulation scheme (MISS) was proposed, and a MISS-based learning system was developed to investigate its effects on facilitating hands-on learning of nasogastric tube (NG) insertion in Taiwanese undergraduate medical students. METHODS A randomized controlled trial (RCT) design was adopted for this research, for which 73 grade-five medical students were recruited. An interactive simulation scheme with a hands-on learning design in a MISS model was built on a web-based application running on mobile devices equipped with the touchscreen. Learning performance including the conceptual knowledge, self-confidence scales, and practical skills (an OSCE-based test) were evaluated to investigate the differences between experimental and control groups. The MISS-based learning system was also evaluated in terms of learning satisfaction, system usability, and task load. The statistical methods used in this work included t-test, ANCOVA, and the Johnson-Neyman analysis. RESULTS he results showed significant differences between the experimental and control groups in terms of both knowledge and self-confidence (P < .001). The levels of image, perceived enjoyment, perceived usefulness, and intention to use scales in the technology acceptance model (TAM) were higher in the high progress group than in the low progress group. Besides, the score of the OSCE test in the experimental group were higher than those in the control group, which had significant difference (t=3.079, P=.003). CONCLUSIONS The proposed MISS-based learning system can efficiently assist students in hands-on learning of nasogastric tube insertion. Accordingly, the learning outcomes and self-confidence can be significantly improved. Moreover, experimental results also show that the useful diagnostic and enjoyment features in the system enhance learners' intention toward use.

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Proposed dual-mode substrate integrated waveguide (SIW) short-circuited coax filter demonstrates a passband that has transmission zeros on both upper and lower stopbands; in addition, such a filter is also inherent with good out-of-band rejection up to three times of the center frequency (fc). There are four signal paths from input port to output port. The signal routings are done by conductor-backed coplanar waveguide (CBCPW) and the slotlines on the top metal. In addition to signal routings,