Mohd Subri Bin Abdul Rani

Electromagnetic Behaviors of Thin Film CPW-Fed CSRR Loaded on UWB Transparent Antenna

The electromagnetic behavior of the coplanar waveguide (CPW)-fed loaded complementary split-ring resonator (CSRR) to the ultrawideband (UWB) transparent antenna is presented in this letter. The transparent material known as conductive silver-coated thin films (AgHT-4) is one of the unique materials that is now being implemented in antenna designs. This material has very unique advantages of very thin thickness and high transparency. However, it exhibits different electromagnetic properties compared to the conventional Fire Retardant-4 (FR-4) due to its surface resistivity and conductivity. Meanwhile, split-ring resonators (CSRRs) are one of the metamaterial artificial structures that are implemented in antenna design for their unique negative permittivity/permeability properties. CSRR will be designed using the transparent material to achieve bandstop filter properties centered at 5.8 GHz so as to reduce the interferences from wireless local area network (WLAN) and dedicated short-range communication (DSRC) applications. The characteristics of the SRRs/CSRRs when implemented on the high resistivity thin film is compared to those implemented using copper radiating element.

A single band dual-fed circular polarization microstrip antenna for RFID application

This paper presents new design for single band circular polarization (CP) antenna with dual feedings. This antenna is designed for RFID application at 2.45 GHz. In this antenna design, the left corner side of the square patch is truncated. Then, two perpendicular feeding is connected to the patch to achieve Circular Polarization antenna. By combining the two perpendicular feedings with the truncated square patch in a dielectric substrate layer, the microstrip antenna for single band frequency circular polarization (CP) can be achieved with - 12.1dB return loss for 2.45 GHz. The simulated and measured results show that the proposed antenna has good circularly polarized radiations and the 3 dB axial-ratio bandwidth is more than 7.2%. Details of the obtained dual-band CP performances are presented and discussed in this report.

Transparent Branch-Line Coupler Using Micro-Metal Mesh Conductive Film

This letter presents the design of a novel transparent 3 dB Branch-Line Coupler (BLC) using a proprietary self-assembling nano-particle technology based Micro-metal Mesh (MM) conductive film. The transparent MM conductive film has a sheet resistance of 0.7 Ω/sq and a visible-light transmission (VBLT) of 75%, resulting in good conductivity and high transparency, respectively. The proposed transparent BLC is mounted on a 2 mm-thick soda-lime glass substrate of dielectric 5.7 and designed to operate at 2.45 GHz. A layer of MM film on the back of the glass serves as a ground. The transparent BLC delivered measured coupling and transmission values of 3.9 and 4.3 dB, respectively. The transparent BLC can be used as a building block for realizing a transparent Butler Matrix (BM) Beam Forming Network (BFN) for Inter/Intra-Vehicle Wireless Communication (IIVWC) in Intelligent Transport System (ITS). Besides being transparent, the proposed BLC has a measured fractional bandwidth of 38.8% and 0.25 mm profile excluding the glass substrate. These advantages greatly enhance the BLCs potential to be used also as a BM building component that can be mounted onto the glass surfaces of buildings for future 5G indoor wireless communications where beam forming is required.

Frequency-Reconfigurable Archimedean Spiral Antenna

In this letter, a frequency-reconfigurable Archimedean spiral antenna is presented. The proposed antenna consists of a two-arm spiral fed by a coplanar waveguide (CPW) feeding line. A pair of meandered slotlines is implemented at both sides of the CPW-fed slot on the spiral antenna to introduce frequency reconfiguration. This antenna is able to configure operating frequencies from wideband mode (2-8-GHz band) to narrowband mode, which is at 5.8 GHz WLAN band, by switching the p-i-n diode integrated within the radiating antenna surface. Two p-i-n diode switches are located in the meandered slot to achieve frequency reconfigurability. Simulated and measured data are presented to verify the proposed antenna design.

Directional UWB antenna with a parabolic ground structure and split ring resonator for a 5.8 GHz band notch

A simple and compact circular planar monopole ultra-wide band antenna with a 5.8 GHz band rejection and directional radiation pattern is proposed in this paper. The split ring resonator (SRR) technique has been utilized to produce band rejection at 5.8 GHz. Some results and analysis on several SRR placements are highlighted in this paper. The parabolic ground structure is used to produce a directional radiation pattern together with bandwidth enhancement. The proposed prototype antenna has acceptable performances in terms of gain, efficiency, and directional radiation pattern. Simulated and experimental results are discussed.

Wideband planar Wilkinson power divider using double-sided parallel-strip line technique

A new design of a wideband Wilkinson power divider using double-sided parallel strip line technique is presented in this paper. To obtain a good isolation value, the proposed design was integrated with three isolation resistors. The proposed power divider is designed for a wide range of frequencies between 2 GHz to 6 GHz with all the ports matched to 50Ω. The conventional quarter wavelength arms are divided into three different widths to ensure wideband capabilities. Moreover, the novelty of the proposed design is illustrated from the double-sided parallel-strip line technique where proposed design is using similar structure at both the top and bottom layers to ensure balance of transmission. All dimensions for the transmission line section were optimized to achieve wideband operation and were integrated with a lumped element. This design can be used as a doublesided feeder for a microstrip antenna.

Archimedean spiral antenna with band-notched characteristics

A coplanar waveguide (CPW)-fed Archimedean spiral antenna with band notched characteristics is presented for ultra- wideband (UWB) applications. The proposed antenna consists of a two-arm spiral fed by a CPW line. The novelty of this design is integrating three inverted U-shaped slots within the feeding line of the spiral antenna to introduce frequency band notched characteristics at 5.8GHz. This antenna covers the frequency range from 3.1GHz to 10.6GHz with VSWR less than 2, except at a band rejection frequency of 5.8GHz. Simulated and measured data are presented to verify the proposed design.