N. Ramli

Aperture-Coupled Frequency and Patterns Reconfigurable Microstrip Stacked Array Antenna

This paper investigates a novel structure of a reconfigurable microstrip antenna integrated with the aperture coupling technique which can reduce spurious radiation pattern with stacked patch in order to enhance the gain and bandwidth performance. The antenna design implements a new concept of the frequency reconfigurability methods applying in an aperture-coupled technique. Four PIN diode switches named as Switch A were used to activate the selected aperture slots on the ground, thus resulting in two different operating frequencies either at 2.6 or 3.5 GHz. Meanwhile, an additional four PIN diode switches named Switch B, positioned at the four L-stub elements were used to turn ON the patterns capabilities while maintaining the frequencies. The beam angle of the antenna can be controlled with turning ON Switch C and Switch D alternately in order to activate selected numbers of stacked radiating patches, either the two upper patches or two lower patches. With six cases of the switches configuration, the antenna has the capability to change its patterns with its beam directed at +32°, +3°, or -1° at 2.6 GHz or at +28°, +23°, or -24° at 3.5 GHz.

Development of Rectangular Loop Microstrip Antenna Integrated with Light Emitting Diode (LED) for Wi-Fi Application

This paper presents the development of a rectangular loop microstrip patch antenna integrated with Light Emitting Diode (LED) for Wifi application. The objective to integrate with LED is to have dual applications in a device which illumination and also wireless communication. The antenna was designed at a frequency of 2.4 GHz and Computer Simulation Technology (CST) was used to optimized the position of LED within the rectangular loop antenna. The performances of the antenna in terms of return loss, gain and radiation pattern was verified through simulation by using Microwave Studio in CST. The antenna was fabricated on FR4 substrate with permittivity, εr = 4.5 and thickness, h = 1.6mm. The LED integrated within the patch was conducted parallel and was measured by Vector Network Analyser (VNA) to demonstrate the capacity and potential of the antenna. The antennas are reasonably well matched at their corresponding frequency of operations between simulation and experiment.

PIN diode switches for frequency-reconfigurable stacked patch microstrip array antenna using aperture-coupled technique

This paper presents a novel design of frequency-reconfigurable antenna by using an aperture-coupled technique as feeding technique and stacked patch technology. The proposed antenna generally consists of three substrate layers (RT-Rogers 5880) and air gap filled between feedline substrate and layer 2 substrates. Four PIN diode (BAP51-02) switches are implemented to configure the length of the feedline by configuring the switches to ON or OFF mode. A new approach of coupling methods is presented. When all the switches are in ON mode, the signal will be passed to the selective aperture slot and activate the particular radiating patch layer to achieve the frequency reconfigurability either at 2.6 GHz or 3.5 GHz. The prototype of the proposed antenna is tested/fabricated with the biasing circuit to validate the performance of the antenna. The simulated and measured results are presented to confirm the performance of the antenna.

UWB microstrip antenna based on circular patch topology with stepped blocks (wing)

This paper presents the design of Ultra Wideband (UWB) microstrip antenna consisting of a circular monopole patch antenna with 3 block stepped (wing). The antenna design is an improvement from previous research and it is simulated using CST Microwave Studio software. This antenna was designed on Rogers 5880 printed circuit board (PCB) with overall size of 26 × 40 × 0.787 mm3 and dielectric substrate, εr = 2.2. The performance of the designed antenna was analyzed in term of bandwidth, gain, return loss, radiation pattern, and verified through actual measurement of the fabricated antenna. 10 dB return loss bandwidth from 3.37 GHz to 10.44 GHz based on 50 ohm characteristic impedance for the transmission line model was obtained.

A Frequency Reconfigurable Stacked Patch Microstrip Antenna (FRSPMA) with aperture coupler technique

This paper presents a novel design of a Frequency Reconfigurable Stacked Patch Microstrip Antenna (FRSPMA) by using an aperture coupler as the feeding technique and stacked technology. The proposed antenna was capable to accommodate at S/X band separately by using the same antenna. Two patches at different substrate are activated sequentially by changing the switch mode at the feedline to achieve frequency reconfigurability. Both patches and feedline are electromagnetically coupled through two small electrical apertures in the ground plane. The design was simulated using CST Microwave Studio at operating 2 GHz to 8 GHz. The effect of aperture slots and the switch configuration either at ON or OFF state were studied. The simulation and measured results were analyzed and discussed of return loss, gain, bandwidth and radiation pattern.

UWB microstrip antenna based on circular patch topology with stepped feedline and partial ground plane

An Ultra Wideband (UWB) microstrip antenna consisting of a circular monopole patch with stepped feedline, with a 10dB return loss bandwidth from 3.50 to 11.20 GHz and maximum VSWR of 1.07 is proposed. This antenna was designed on Rogers 5880 printed circuit board (PCB) with overall size of 31.17 × 40 × 0.787 mm3 and dielectric substrate εr = 2.2. This antenna operated at UWB frequency and it designed by using CST Software based on the 50Ω characteristic impedance for the transmission line model. The antenna yielded a doughnut shaped radiation pattern throughout the UWB frequency band.

Design of an aperture-coupled frequency-reconfigurable microstrip stacked array antenna for LTE and WiMAX applications

The aim of this paper is to design a novel structure of a frequency-reconfigurable microstrip array antenna by using a combination of aperture-coupled and the stacked patch technology. The four sets of two different aperture slot shapes (I-shaped and H-shaped) are printed on the ground and are functional to transfer the wave and the signal to the selected radiating layers. Both aperture slot positions are based on the bottom patches (layer 2) and top patches (layer 1), respectively. To achieve the frequency reconfigurability, four PIN diode switches are integrated on the feed line layer positioned between both aperture slots on the ground.The activation of the selected patches will determine the current operating frequency of the proposed antenna. A 2.6GHz or 3.5GHz frequency is achieved by switching all the PIN diode switches to ON or OFF mode synchronously. The advantage of the proposed antenna is that it can minimize the usage of the antennas surface area, with different size of the patch having different operating frequencies, sorted in different layer. The measured results of the return losses, radiation patterns, and the practical indoor propagation measurement achieved good agreement with the simulated results.

Aperture-Coupled Frequency-Reconfigurable Stacked Patch Microstrip Antenna (Frspma) Integrated with PIN Diode Switch

In this paper, a new Frequency-Reconflgurable Stacked Patch Microstrip Antenna (FRSPMA) with a new coupling method applied in an aperture-coupled technique controlled by the switching circuit is presented. This antenna uses a combination of aperture- coupled technique and stacked patch in order for the radiating elements to increase the bandwidth. Two shapes (I-shape and H-shape) and sizes of aperture slots are etched onto the ground with a purpose to couple the energy between feedline and stacked patch. One PIN diode switch is integrated in the feed network to control the length of the feedline. A variation of the feedline length controls the selected aperture slots to be active. The waves from the selected activated aperture slots will radiate to particular radiating patch (top or bottom patch) and achieve the frequency reconflgurability. When the switch is in ON mode, the antenna has a capability to conflgure its operating frequency at 2.6GHz and at 3.5GHz during the OFF mode. Besides that, the air gap is used to improve and avoid any coupling problem between the aperture slots and both of the two patches. Improper alignment between the aperture slots and patches will interfere waves radiating from aperture slots to the particular patch. In addition, the proposed antenna produces a high gain of more than 5dB during ON or OFF modes, respectively. The simulated results are compared with measured results.

Reconfigurable Microstrip Stacked Array Antenna with Frequency and Pattern Characteristics

This paper presents a frequency and pattern reconflgurable stacked patch microstrip array antenna fed by aperture-coupled technique. The antenna consists of three substrate layers with radiating elements sorted at substrate layer 1 (top patches) and substrate layer 2 (bottom patches). The layers have difierent sizes to indicate difierent operating frequencies. On the ground plane, the four sets of two difierent aperture slot shapes (I-shaped and H-shaped) are used to transfer the wave and signal to particular radiating elements during the PIN diode switches conflgurations. The I-shaped slots are used to activate the bottom patches while the H-shaped slots are used to activate the top patches. Four PIN diode switches are placed at the feed line, positioned between the I- and H-shaped slots. Next, by changing the PIN diode switches conflguration to ten cases, the proposed antenna has capabilities to change the operating frequencies and the pattern characteristics itself. The measured results of return loss, gain and radiation patterns have slightly shifted compared to the simulated results.