Hattan F. AbuTarboush

A Reconfigurable Wideband and Multiband Antenna Using Dual-Patch Elements for Compact Wireless Devices

A reconfigurable wideband and multiband C-Slot patch antenna with dual-patch elements is proposed and studied. It occupies a compact volume of 50 × 50 × 1.57 (3925 mm3), including the ground plane. The antenna can operate in two dual-band modes and a wideband mode from 5 to 7 GHz. Two parallel C-Slots on the patch elements are employed to perturb the surface current paths for excitation of the dual-band and the wideband modes. Two switches, implemented using PIN diodes, are placed on the connecting lines of a simple feed network to the patch elements. Dual-band modes are achieved by switching “ON” either one of the two patch elements, while the wideband mode with an impedance bandwidth of 33.52% is obtained by switching “ON” both patch elements. The frequencies in the dual-band modes can be independently controlled using positions and dimensions of the C-Slots without affecting the wideband mode. The advantage of the proposed antenna is that two dual-band operations and one wideband operation can be achieved using the same dimensions. This overcomes the need for increasing the surface area normally incurred when designing wideband patch antennas. Simulation results are validated experimentally through prototypes. The measured radiation patterns and peak gains show stable responses and are in good agreements. Coupling between the two patch elements plays a major role for achieving the wide bandwidth and the effects of mutual coupling between the patch elements are also studied.

Multiband Inverted-F Antenna With Independent Bands for Small and Slim Cellular Mobile Handsets

The design of a small ultra-thin printed inverted-F antenna (PIFA) with independent control on the resonant frequency bands is proposed. The antenna consists of a slotted radiator supported by shorting walls and a small ground plane. The structure is designed and optimized to operate at 2.09, 3.74 and 5 GHz with achievable bandwidths of 11%, 8.84% and 10%, respectively. These three bands cover the existing wireless communication frequency bands from 1.5-6.8 GHz. Each of the three bands can be controlled independently without affecting the other two bands. The 2.09 GHz band can be controlled to operate between 1.5-2.09 GHz (33.33%), the 3.74 GHz band can be controlled over the range of 3.57-4.18 GHz (15.76%) and the 5 GHz band can be controlled to cover the band from 5.00-6.80 GHz (30.50%). Results of intensive investigations using computer simulations and measurements show that the ground plane and the feed locations of the antenna have marginal effects on the performance of the antenna. The effects of the users hand and mobile phone housing on the return loss, radiation patterns, gains and efficiency are characterized. The measured peak gains of the prototype antenna at 2.09, 3.74 and 5 GHz are 2.05, 2.32 and 3.47 dBi, respectively. The measured radiation efficiencies for the corresponding three bands are 70.12, 60.29 and 66.24% respectively.

Multiband and Wideband Monopole Antenna for GSM900 and Other Wireless Applications

In this letter, the design of a compact monopole antenna for multiband and wideband operations is proposed. The antenna has three distinct frequency bands, centered at 0.94, 2.7, and 4.75 GHz. The antenna has a compact size of only 30 × 40 × 1.57 mm including the ground plane. The multiband and wideband operations are achieved by using an E-shaped slot on the ground plane. The design procedure is also discussed. The frequency bands can be independently controlled by using the parameters of the E-slot. The impedance bandwidth, current distributions, radiation patterns, gain, and efficiency of the antenna are studied by computer simulation and measurements.

Compact Printed Multiband Antenna With Independent Setting Suitable for Fixed and Reconfigurable Wireless Communication Systems

This paper presents the design of a low-profile compact printed antenna for fixed frequency and reconfigurable frequency bands. The antenna consists of a main patch, four sub-patches, and a ground plane to generate five frequency bands, at 0.92, 1.73, 1.98, 2.4, and 2.9 GHz, for different wireless systems. For the fixed-frequency design, the five individual frequency bands can be adjusted and set independently over the wide ranges of 18.78%, 22.75%, 4.51%, 11%, and 8.21%, respectively, using just one parameter of the antenna. By putting a varactor (diode) at each of the sub-patch inputs, four of the frequency bands can be controlled independently over wide ranges and the antenna has a reconfigurable design. The tunability ranges for the four bands of 0.92, 1.73, 1.98, and 2.9 GHz are 23.5%, 10.30%, 13.5%, and 3%, respectively. The fixed and reconfigurable designs are studied using computer simulation. For verification of simulation results, the two designs are fabricated and the prototypes are measured. The results show a good agreement between simulated and measured results.

A Novel Technique and Soldering Method to Improve Performance of Transparent Polymer Antennas

A novel technique and a nonthermal soldering method to improve the performance of AgHT-8 transparent polymer antennas are proposed in this letter. The proposed technique involves the removal of the coating layer at areas on the coplanar waveguide (CPW) ground and feed line where the connectors of the coaxial feed or legs of the SMA connectors will be attached and applying a coat of silver paint on the exposed areas before cold-soldering the coaxial connections or SMA connector legs. The nonthermal or cold soldering using electrically conductive paste enables direct soldering of the coaxial feed points or connector legs, which cannot otherwise be done with hot or thermal soldering. This type of connection greatly enhances the performance of the AgHT-8 polymer antennas compared to coaxial feed point connections through hot-soldered copper pads glued to the surface of the polymer coating. The proposed technique also gives a stronger connection bond than directly cold-soldering the feed points or connectors to the smooth surface of the AgHT-8 material. Furthermore, the copper pad connection technique also introduces additional losses contributed by the adhesive properties of the glue used. This proposed novel technique and soldering method may be extended to enhance antenna performance made from other similar transparent conductive polymers like ITO.

Miniature transparent UWB antenna with tunable notch for green wireless applications

In this paper, the design of a UWB antenna using a transparent AgHT-8 material is proposed for green wireless applications. Computer simulation is used for studies. For verification of the design, the proposed antenna is fabricated on an AgHT-8 film and measured. Results show that the antenna has better radiation efficiency relative to its size than the previous designs, good omni-directional radiation patterns throughout the FCC bandwidth of 3.1–10.6 GHz and a comparable gain. To filter out the unwanted signals in the WLAN band, two vertical slots are introduced to produce a tuning notch in the 5 GHz frequency band. For demonstration of green wireless applications, the transparent antenna is incorporated with a solar panel for harnessing solar energy. Results show that the transparency of the antenna makes it a good candidate for future green wireless applications.

Compact dual-band (2.4/5.2GHz) monopole antenna for WLAN applications

A compact and optimized design of a rectangular printed monopole antenna with slits and truncated ground plane on FR-4 substrate is presented. The proposed antenna is designed for dual-band operation at 2.4 GHz and 5.2 GHz for Wireless Local Area Network (WLAN) applications with S11≪ −10 dB. This antenna has good return loss and radiation characteristics in required frequency band. The proposed antenna gives omni-directional radiation pattern in the E Plane and H plane over the frequency range of 2.4 GHz and 5.2 GHz. The calculated and measured results in terms of return loss show good agreement and the results also show good wideband characteristics.

Bandwidth enhancement for microstrip patch antenna using stacked patch and slot

Small size wideband microstrip patch antenna with slot in ground plane and stacked patch fed through microstrip line is presented. By inserting slot on ground plane and stacked patch supported by wall, the bandwidth can improve up to 25% without significant change in the frequency. The bandwidth before adding the slot and the stacked patch was 3.72%, whereas after adding the slot and the stacked patch the bandwidth increased up to 25% ranging from 2.45 to 3.3 GHz. The radiation pattern has acceptable response at both E-plane and H-plane. The ground plane size is 30 mm by 90 mm, the antenna designed is based on Roger RT/duroid 5880 with dielectric constant 2.2.

Design of planar inverted-F antennas (PIFA) for multiband wireless applications

A small three bands printed inverted-F antenna with independently controlling the resonant frequency is presented. The proposed antenna consists of two arms supported by shorting walls fed by 50 Ω microstrip transmission line and a ground plane. The antenna occupied a compact size of 26 × 25.6 × 3.75 mm3. The main radiated patch injected with slot and another arm to generate and control the three resonant frequencies to cover 2.4, 3.7 and 5.2GHz Wireless Local Area Network (WLAN) and Worldwide Interoperability for Microwave Access (WiMAX). The simulated and measured results show that the antenna achieves a gain of 2, 3 and 5 dBi respectively and radiation efficiency of 50%, 60% and 85% for the three bands respectively. The simulated and measured result for the return loss is in good agreements.

Inkjet-Printed Wideband Antenna on Resin-Coated Paper Substrate for Curved Wireless Devices

A low-cost, inkjet-printed multiband monopole antenna for conformal wireless applications is presented for the first time. The antenna is implemented on a low-cost resin-coated paper substrate which can be used for conformal devices. The antenna developed here is composed of four branch lines on the radiator and three L-shaped slots on the ground plane that help to generate multiple bands without increasing the size of the antenna. The antenna has a compact size, making it suitable for handheld and wearable wireless devices. Details of the inkjet printing fabrication processes and related issues are presented. The antennas were characterized under flat and bent conditions, and the results indicate that the antennas can cover most bands for mobile and wireless applications such as PCS, UMTS, GSM1900, and WLAN.