M. Z. M. Nor

A Dual-Band Diamond-Shaped Antenna for RFID Application

A novel dual-band single-layer substrate and diamond-shaped antenna is presented. The proposed antenna operates in dual-band frequency at UHF band (from 902 to 920 MHz) and ISM band (from 2.4 to 2.5 GHz), which is suitable for RFID application. Antenna frequencies were controlled by the shape and size of the radiating element. The proposed prototype antenna also has acceptable performances in terms of gain, efficiency, and directional radiation pattern. The antennas gain and efficiency are 7.8 dBi and 87 %, respectively, at the lower frequency band, while the corresponding values are 9.4 dBi and 94 % at the higher band. When compared to the simulated results, the measurements show good agreement in terms of return loss and radiation pattern.

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.

Dual-Band, Switched-Beam, Reconfigurable Antenna for WLAN Applications

The development of WLAN technology requires antennas with additional capabilities using simple and low-cost mechanisms. This letter presents a low-cost microstrip antenna integrated with simple p-i-n diodes as RF switches. The proposed antenna is capable of steering the beam in a dual-band mode: -19°, -59°, and 61° within the 2.45-GHz band, and 6°, -14°, and 16° within the 5.8-GHz band, which meets the IEEE 802.11a, b/g requirements. The antenna consists of three different dual-band elements, connected using an H-shaped transmission line at the radiating side. The novelty of this structure lies in the ground plane design. The H-shaped transmission line is used to integrate three different ground-plane structures.

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.

Dual band circularly polarized diamond-shaped antenna with directional capabilities for RFID application

A simple and novel diamond-shaped structure capable of producing dual band antenna with circular polarized enhancement is presented. The proposed antenna operates at both UHF and ISM bands which is suitable for RFID application. A pair of slots is introduced at the blended edge within the radiating element with optimum width and length, which can excite circular polarized antenna for both frequencies. The proposed antennas gain is improved by using a fixed air gap between substrate and ground plane. It is observed that there is good measure of agreement between the simulation and measurement return loss result, when compared.

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.

Dual-band, parabolic, slotted ground plane-directive antenna for WLAN applications

Wireless local area network (WLAN) is one of the common terms used by researchers in the communications area that allows wireless, long-range communication. Antennas are used as a medium of transmission, and in recent WLAN applications, manufacturers have tended to use antennas which are small, have simple structures, are inexpensive, and can operate at several sets of frequencies. In this paper, a dual-band antenna with defected ground plane structure is introduced. With the proposed combination of slots in its radiating element and defected ground plane, the antenna can operate at two frequency bands 2.45 and 5.8 GHz and direct the main beam at 30° at these respective bands. Simulated results and measurements show good agreement in terms of return loss and radiation pattern.

Slotted dual band directive antenna with defected ground plane structure

WLAN is one of the common term that being used as many researchers where WLAN is one of the application that allows long range communication unwired. With the combination of slots in radiating element, and parabolic slotted shape at the ground plane, proposed antenna can operate at two sets of WLAN application band and their main beam can be directed at -62° and -43° at 2.45 GHz and 5.8 GHz respectively. Proposed antenna is suit to be used in WLAN application such in Bluetooth, Wi-Fi and access point (AP) application.