This paper presents a designed coupler by using substrate Roger RO4003. The four port network coupler operates at (18-26 GHz) and designed by using substrate integrated waveguide (SIW) method. Substrate Integrated Waveguide (SIW) are high performance broadband interconnects with excellent immunity to electromagnetic interference and suitable in microwave and millimetre-wave electronics applications, as well as wideband systems. The designs of the coupler are investigated using CST Microwave Studio simulation tool. These proposed couplers are capable of covering the frequency range and provide better performance of scattering parameter (S-parameter). This technology is successfully approached for millimetre-wave and microwave applications. Designs and results are presented and discussed in this paper. The overall simulated percentage bandwidth of the proposed coupler is covered from 18 to 26 GHz with percentage bandwidth of 36.36%.

Technology for radio frequency identification (RFID) is commonly used worldwide. RFID is a developing wireless technology which make new vital challenge. The ability to precisely read a set of RFID tags become major concern in RFID networks coverage Detailed analysis of the design based on the 13.56 MHz radio frequency was suggested to design a kind of RFID reader antenna. Previously, researchers did facing problem with the size of the antenna which was to maintain the compact size at low frequency is challenging. The proposed antenna will be designed in the shape of rectangular spiral which contribute into miniaturize of the antenna size. The antenna will be fabricated after the optimum length and width had been achieved. The goal of this project is to design a small size antenna with 55mm × 55 mm at frequency resonance of 13.56 MHz. to reduce the antenna gain on the future. We are going to design and add the metamaterial to the RFID reader antenna and combine them together and that will help to reduce the antenna gain.

Substrate Integrated Waveguide (SIW) involves the conductive via holes immersed in a dielectric substrate that connects two substrate plates. This article presents a new SIW technique to enhance the operational bandwidth of the Riblet Short-Slot coupler. To demonstrate the proposed SIW technique, two Riblet Short-Slot couplers are designed and investigated at two different high-frequency ranges, Ku-band and K-band. The bandwidth of the proposed couplers is improved by introducing multiple layers of SIW vias at the center of the couplers’ side wall. Applying this approach minimizes the leakage loss between vias, indicating an improved overall operating bandwidth of 36.31% and 26.32% for Ku-band and K-band, respectively. All vias in both prototypes are realized using an alternative method, without using the Plated-Through-Hole Printed-Circuit-Board (PTH-PCB) machine. In addition, experimental results agree well with the simulated results.

Screw pine plant, scientifically know as Pandanus atrocarpus , thrive abundantly across Asia. This study examines the morphology, functional structure, thermal and dielectric properties of fibers extracted from Pandanus atrocarpus leaves. The water-based retting method, facilitated by microbial activity, was utilised to extract the Pandanus atrocarpus fibres from the leaves. Microfibrils vertical alignment was observed on the morphology of leaf fibres with the random measured diameter ranging from 392.2 µm to 406.3 µm. Fourier transform spectroscopy confirmed the existence of cellulose and amorphous constituents. Pandanus atrocarpus leaf retains thermal stability up to 220°C before experiencing degradation of hemicellulose at 296°C, and cellulose at 359°C, as verified by DTG and DSC analyses. The effect of adding Pandanus atrocarpus leaf fibres in epoxy composite improves the dielectric properties across a wide frequency by promoting the interaction of polar molecules and displacement currents, leading to greater orientation polarization, thus well-suited for suitable for polymerization over various high frequency applications.

In this era of technology, EMC application have become more important because the increase of electronic devices due to the demand from users. Every electronic appliance is a source of radiated electromagnetic fields called radiated emission. Hence, it is important to make sure the radiation is in a safe level where an antenna will be used to detect the radiated electromagnetic fields. The existing antenna used for EMC testing such as log-periodic antenna, fractal antenna and biconical antenna have a large dimension that make it hard to set up for the testing and majority can only operate starting from 3 GHz and above. In order to overcome that problem, an ultra-wideband monopole patch antenna is proposed which aimed to be operated from 0.7 to 6.8 GHz for EMC testing. The UWB antenna can be achieved by having a truncated ground plane and notches at the ground structure. The edges of the rectangular patch antenna have been cut to improve the return loss and a tapered feed is implemented to increase the gain. To design and simulate the proposed antenna, CST Microwave Studio software has been used in this project to get the desired result which is the return loss and gain. The design for this antenna is very simple to ease the fabrication process. Overall, the structure consists of an antenna patch with a rounded rectangular shape, tapered feed line, and a truncated ground plane with notches at both corners. The simulation result of reflection coefficient of the antenna is at 0.7 GHz up to 6.8 GHz which has a high bandwidth efficiency at 162%, and have a good gain which is in around 2 to 5.6 dB if compared to the previous study by [1], as the bandwidth efficiency was 109% and gain values varies between 1 to 3.83 dB only.