In this paper, a miniaturized implantable circularly polarized spiral Planar Inverted-F Antenna (SPIFA) in the UHF (600-800 MHz) band is presented. This antenna is intended for deep implantable devices such as leadless pacemakers and deep brain stimulation (DBS), which facilitates the reception of RF power from an external transmitter. The antenna is electrically small, with a volume of π × 5 mm × 5 mm × 3.2 mm and a diameter of 0.022λ. The performance of the proposed antenna in terms of reflection coefficient, realized gain and axial ratio are assessed when accounting for the effects of operating in different types of human body tissues, different biocompatible materials and different thicknesses and depths of the implanted antenna. Finally, the antenna is prototyped and measured in free space, a phantom model, in a cow’s fat and muscle tissues to validate the simulation results, indicating good agreements. A realized gain around -20 dBm is achieved when operating in 50 mm depth in cow’s muscle tissue while having electrically very small dimensions compared to implantable antennas reported in the literature.

This study presents a new method for measuring the propagation constant of transmission lines using a single line standard and without prior calibration of a two-port vector network analyzer (VNA). The method provides accurate results by emulating multiple line standards of the multiline calibration method. Each line standard was realized by sweeping an unknown network along a transmission line. The network need not be symmetric or reciprocal, but must exhibit both transmission and reflection. We performed measurements using a slab coaxial airline and repeated the measurements on three different VNAs. The measured propagation constant of the slab coaxial airline from all VNAs was nearly identical. By avoiding disconnecting or moving the cables, the proposed method eliminates errors related to the repeatability of connectors, resulting in improved broadband traceability to SI units.

This paper presents a compact four-port multiple-input multiple-output (MIMO) antenna operating in the Ku-band around 13 GHz, targeting early-phase 6G upper-midband front-end applications. The proposed antenna employs orthogonally arranged short-ended square patch elements combined with a modified defected ground structure (DGS) to achieve high port isolation and compact footprint. A prototype fabricated on Rogers RO4350 substrate demonstrates good agreement between simulated and measured results. The antenna achieves $|S_{11}|$ < −10 dB over 12.9–13.1 GHz band, inter-port isolation exceeding 25 dB, and an envelope correlation coefficient (ECC) below $0.01$. The measured realized gain reaches 7.02 dBi with a radiation efficiency above 80%. Compared with recent Ku-band MIMO antennas, the proposed design provides a 45% size reduction while maintaining high isolation at a close element spacing of 0.25${\lambda }_0$. The proposed antenna intentionally adopts a narrowband operating characteristic, reflecting a design trade-off that prioritizes compact size, high isolation, and low spatial correlation over wideband performance. These features make the antenna well suited for early-stage 6G-oriented front-end modules, fixed wireless access, backhaul links, and short-range sensing systems operating in the upper-midband frequency range.

Background. Clinical guidelines are texts developed to assist both physicians and patients in deciding on the most appropriate health care. This study evaluated the compliance of emergency performance with clinical guidelines at Sina Medical Training Center in Tabriz. Methods. This descriptive-analytical study was conducted on a case study at Sina Hospital under the supervision of Tabriz University of Medical Sciences. In the first stage, as a research tool, a checklist, approved in terms of validity and reliability, was set up to evaluate clinical guidelines. The second phase of this study was cross-sectional, conducted in a period of one month. All medical records of people referring to level 1 and 2 triage were reviewed based on the checklist and the data were entered into SPSS software, and since the normality of the data was confirmed, descriptive statistics and parametric tests (t-test and ANOVA) were used to analyze the data. Results. Considering the mean (1.72 ± 0.097) in this study, the adherence to clinical guidelines seems to be higher than average. The results also showed that there was no significant relationship between any of the demographic variables and the mean score of total compliance with the guidelines (P-value> 0.05). However, among other variables, a significant relationship was found between the place of the patient's visit as well as the type and time of patient assignment on the one hand and the average score of total compliance with the guidelines (P-value<0.05). With regard to the results of the regression test, patient’s place of visit was the only appropriate variable to predict the average of the total observance of emergency clinical guidelines (P-value<0.05). Conclusion. Considering the effect of influential variables such as location of the patient's visit, the time and type of patient assignment on the observance of the guidelines and the increasing improvement of the situation of these variables, the average observance of clinical guidelines can be improved further

This study presents a new method for measuring the propagation constant of transmission lines using a single line standard and without prior calibration of a two-port vector network analyzer (VNA). The method provides accurate results by emulating multiple line standards of the multiline calibration method. Each line standard is realized by sweeping an unknown network along a transmission line. The network need not be symmetric or reciprocal, but must exhibit both transmission and reflection. We performed measurements using a slab coaxial airline and repeated the measurements on three different VNAs. The measured propagation constant of the slab coaxial airline from all VNAs is nearly identical. By avoiding disconnecting or moving the cables, the proposed method eliminates errors related to repeatability of connectors, resulting in improved broadband traceability to SI units.