Menentukan Intensitas Radiasi UV yang Diterima Pekerja Pengelasan dengan Titik Area Mata, Siku, dan Betis

The aim of this study is to measure the UV intensity received by the welders during working time and compare the results of measured radiation intensity which is obtained with the NAB in Regulation of the Minister of Manpower No. 05 of 2018 that is 0,0008 mW/cm2. The reason for using this NAB is for compare value while welding process with the value were allowed from Regulation of the Minister of Manpower. This study has been done in some workshops using the UV Meter and focused on the welders’ eye, elbow and calf area with 10 repetitions in each area. The results for eye area were 0.0749 mW/cm2, for elbow area were 0.0843 mW/cm2and for calf area were 0.0934 mW/cm2and all the results obtained exceed the NAB. The high value is caused by the environmental conditions is open and also affected by indeterminate sunlight, the risks received the welders in watery eye and headache because of the welder are disobey in using PPE while welding process.

A Compact CPW-Fed UWB Antenna with Dual-Band Notched Characteristics for WiMAX/WLAN Applications

A dual-notched bands ultra-wideband (UWB) antenna with coplanar waveguide (CPW) fed is presented in the paper. The two notched bands are selected at 3.5 and 5.8 GHz frequencies to overcome the interference from WiMAX and WLAN bands. The overall size of the antenna is 17.5×17.5 mm2, which can be considered as one of the smallest UWB antennas in the literature. The developed antenna has an impedance band width ranging from 2.9 to 13 GHz. The measured radiation patterns on E and H planes are nearly omni-directional and stable with acceptable gain over the entire band. The dual-band notched at WiMAX and WLAN is created by embedding I-shaped and C-shaped stubs in the radiation patch of the antenna. Due to the compactness, good radiation patterns and the reasonable stable gain, this antenna is well suited for integration into portable wireless communications devices for UWB applications.

Multiband Cross-Shaped Inverse Triangular Notch Antenna for Radio Shadow Zone Communication

This paper proposes a multiband cross-shaped inverse triangular notch antenna on a circular ground plane for a radio shadow zone mobile communication design for a broadband repeater antenna in the firefighting band for in-building mobile communication. To arrive at the broad and multi-bandwidth reflection coefficients, methods are considered for optimizing the cross-shaped notch antenna with an inverse triangular structure and the circular ground plane. The measured reflection coefficients are observed −10 dB lower in the firefighting band (440–450 MHz) and the mobile repeater band (890–2,450 MHz), and they agree well with those obtained through simulation. The desired omni-directional patterns are obtained in the firefighting band, even though the radiation patterns in the Wi-Fi band have directivity from 10° to 15° and from −10° to −50°. The measured radiation patterns and gains also agree well with the predictions.

Design, Simulation and Experimental Validation of Wideband DGS Circularly Polarized Micro Strip Patch Antenna For C-Band Satellite Communication Applications

Satellites are very prominent for current and future communication applications like broadcasting, 5G and Military Communications. Most of the Satellites are used for radio communication. For communicating purpose, the satellite antenna must have unique characteristics such as circular polarization, broad beam width and good axial ratio. In order to have such type of unique characteristics, the micro strip patch antenna is the suitable antenna for Satellite applications because of its advantages. In this paper, a Wide band DGS circularly polarized micro strip patch antenna has been proposed for C-Band Satellite Communication Applications. Two defects or slots are introduced in the ground plane and those are orthogonally overlapped to get the circular polarization characteristics. In addition to this, these two slots enhance the bandwidth of the patch antenna by tuned to different frequencies. Moreover, the patch with defective ground structure is simulated and fabricated. Also measurements are carried out and obtained results are compared with the simulated results. It is noted that all the simulated and measured radiation patterns of the antenna have been carried out for all the frequencies and data has been compiled. However, some of the simulated and measured radiation patterns are included in this paper due to space constraint.

Beam Scanning Capabilities of a 3D-Printed Perforated Dielectric Transmitarray

In this paper, the design of a beam scanning, 3D-printed dielectric Transmitarray (TA) working in Ka-band is discussed. Thanks to the use of an innovative three-layer dielectric unit-cell that exploits tapered sections to enhance the bandwidth, a 50 × 50 elements transmitarray with improved scanning capabilities and wideband behavior has been designed and experimentally validated. The measured radiation performances over a scanning coverage of ±27 ∘ shown a variation of the gain lower than 2.9 dB and a 1-dB bandwidth in any case higher than 23%. The promising results suggest that the proposed TA technology is a valid alternative to realize a passive multibeam antenna, with the additional advantage that it can be easily manufactured using 3D-printing techniques.

Compact five-band antenna array with vertical polarization

A vertical polarized antenna array operating in frequency bands 423–443, 840–930, 1525–1625, 2400–2500 and 5725–5850 MHz is presented. The radiators are made in a shape of stacked patches excited by metal strips located under the radiating patches. The radiating patch of the lowest frequency band 423–443 MHz is made in the form of a printed circuit board and acts as a reflector for radiators operating at other frequency bands. Such two-storey structure provides small dimensions of the antenna array. The results of simulation are compared with the measured radiation patterns and S parametes of the manufactured antenna array.