Folded Patch Feed Research Articles

Compact multi-band stacked circular patch antenna for wideband applications with enhanced gain

ABSTRACTThis paper presents a probe-fed compact multi-band microstrip patch antenna for wideband operation. The proposed antenna is composed of a shorted circular patch fed by folded-patch with a V-shaped slot and two stacked circular patches. Two stacked patches with different diameters are suspended by two shorting pins above the circular patch to achieve a multi-band antenna. The proposed design without stacked patches with a folded-patch feed introduces an ultra-wideband (UWB) antenna with the measured bandwidth of 115.8% in 3.68–13.8 GHz. The proposed stacked design introduces the tuning ability of the frequency bands by changing the diameters of two stacked circular patches. The first and second measured −10 dB bands cover 3.27–4.35 GHz (28.4%) and 5.15–6.40 GHz (21.7%) for worldwide interoperability for microwave access (WiMAX) and wireless local area network (WLAN) operations, respectively. The third measured −10 dB band operates in 9.2–14 GHz with a wide impedance bandwidth (more than 41%). Likewise, good antenna performances such as broadside radiation patterns, acceptable miniaturization and high gain over the operating bands have been observed. Detailed simulations based on the parametric study are performed to identify the triple-band performance of the proposed design.

A Small Ultra-Wideband Half-E Folded Patch Antenna with a Shorting Pin

A small fourth wavelength Ultra-Wideband half-E antenna with a shorting pin and folded patch feed is presented in this paper. This patch antenna has half structure, folded patch and a shorting pin to create a Ultra-wide impedance band patch antenna with small geometric size. The antenna sizes are 7.5mm15mm7mm (0.188λ00.376λ00.175λ0, where λ0 is the free space wavelength corresponding to the center frequency at 7.52GHz) and about 70.21% is obtained. The impedance bandwidths, radiation patterns, radiation efficiencies and gains of the antenna are discussed.

Analysis on bandwidth enhancement of compact probe‐fed patch antenna with equivalent transmission line model

In this paper, a comprehensive study of miniaturised broadband microstrip patch antennas for ultra-wideband applications is presented. At first, design and analysis of a compact wideband basic antenna which is composed of a folded-patch feed, a symmetric E-shaped edge, a U-shaped-slot patch and shorting pins are studied and investigated. The measured −10 dB impedance bandwidth of the proposed basic antenna is about 92% in the frequency range 3.94–10.65 GHz. To explicitly demonstrate the mechanism of the bandwidth enhancement method, the equivalent transmission line model of the basic antenna is exhibited. This model contributes the effect of different parts used in the basic antenna structure in order to predict the broadband behaviour of it. Moreover, with the use of a V-shaped slot instead of the U-shaped slot on the patch, an improved antenna with a wider bandwidth in order to cover the frequency range from 4 to 14.4 GHz is obtained. This improved design introduces comparatively a simpler structure with considerable size reduction and an enhancement of 21% in impedance bandwidth compared with the basic antenna. Experimental investigations and detailed simulations based on the parametric study are performed to describe and optimise the broadband performance of the proposed designs.

A low-profile patch antenna for ultrawideband application

In this letter, a low profile stacked patch antenna is proposed for UWB operations. The antenna design is comprised of three patches; a 35° angularly folded patch feed (bottom patch), T-shaped patch (middle patch), and strip-loaded patch (top patch). The wide bandwidth is achieved with the integration of a 35° angularly folded patch feed with a T-shaped patch. The antenna's size is reduced by using the shorting wall technique. The existence of electromagnetic coupling between the T-shaped patch and strip-loaded patch further improves the impedance bandwidth. The design exhibits a compact electrical dimension of 0.12λ×0.14λ×0.08λ, where λ is the wavelength of the lowest operating frequency. The measured results showed that the antenna can achieve a bandwidth of 107.46% (3.1-10.3 GHz). Acceptable gain, stable radiation patterns, and low group delay variation in the operating band are achieved as well. These measured results signify the effectiveness of the proposed antenna configuration in the context of UWB application.

Design of an Ultra-Wideband Microstrip Patch Antenna Suspended by Shorting Pins

Designing a compact wideband microstrip patch antenna which is composed of a folded-patch feed, a symmetric E-shaped edge and shorting pins is presented in this paper. One pin is applied in order to expand the impedance bandwidth. Two other pins are utilized to miniaturize the size of patch as well. The measured impedance bandwidth ( $$\text{ VSWR}\le 2$$ ) of the fabricated antenna is more than 90 % in the frequency range 3.92---10.67 GHz for ultra-wideband (UWB) applications. The antenna size is $$0.438\lambda _{0}\times 0.365\lambda _{0}\times 0.170\lambda _{0}$$ at its center operating frequency. Also, radiation patterns with acceptable stability within the bandwidth are obtained. In addition, the effects of some key parameters are investigated to describe the performance of the proposed design.

Miniaturised asymmetric E‐shaped microstrip patch antenna with folded‐patch feed

A design of probe-fed compact wideband microstrip patch antenna which is configured of an asymmetric E-shaped patch, a folded-patch feed and shorting pins, is presented in this study. In this design, unequal resonance arms fed by a folded patch produce three resonances to broaden the impedance bandwidth. Shorting pins are applied to miniaturise the size of the patch. The performance of broadening the impedance bandwidth is explored by investigating the behaviour of the surface currents on the patch. The antenna presents resonance tuning ability within the impedance bandwidth by varying the length of unequal arms. The measured -10 dB impedance bandwidth of the fabricated antenna is 76.18% from 3.34 to 7.45 GHz for ultra-wideband applications. The size of this antenna is 0.379 λ L × 0.145 λ L × 0.078 λ L , where λ L is wavelength at the lower frequency of the measured operating bandwidth in the free space. Fabrication of this antenna is less complex than similar wideband antennas with folded-patch feed. In addition, parametric studies are performed by investigating the effects of different key parameters on obtaining an optimal design of the proposed antenna design.

Enhanced Bandwidth of Shorted Patch Antennas Using Folded-Patch Techniques

This letter introduces novel designs of miniaturized wideband microstrip patch antennas for ultrawideband (UWB) applications. The antennas are achieved by using folded-patch feed's techniques and shorting pins to provide the impedance bandwidths $({\rm VSWR} \leq 2)$ of 94.17% (4.13–11.48 GHz) and 98.22% (3.57–10.46 GHz), respectively. By introducing a folded ramp-shaped feed, the impedance bandwidths of the proposed antennas are considerably enhanced. Shorting pins are utilized to miniaturize the size of the patches. In the first design, unequal arms fed by a folded ramp-shaped patch produce three resonances to broaden the impedance bandwidth. Also at the second design, by adding one pin in the center of the shorted patch with a folded ramp-shaped feed, a broadband antenna is obtained. In addition, the wideband mechanism of the proposed antennas is described and discussed by investigating the effects of some key parameters.

ULTRA-WIDEBAND SHORTED PATCH ANTENNAS FED BY FOLDED-PATCH WITH MULTI RESONANCES

Novel designs of probe-fed broadband shorted patch antennas for ultra-wideband (UWB) applications are presented in this paper. In these designs, unequal resonance arms fed by a folded patch produce multi resonances to broaden the impedance bandwidth. In the flrst design, the antenna consists of an asymmetric E-shaped patch, a folded-patch feed and shorting pins. This antenna is achieved by four adjacent resonances with the measured i10dB impedance bandwidth of 76.18%. The pins are utilized to miniaturize the size of the patch. By introducing a folded ramp-shaped feed in the similar structure with the flrst design, a wider bandwidth with the flve resonances is obtained. This improved design introduces an antenna with an impedance bandwidth of more than 110% and a considerable size reduction compared to the flrst antenna. The antennas present resonance tuning ability within the impedance bandwidth by varying the length of unequal arms. In addition, parametric studies are performed by investigating the efiects of difierent key parameters on obtaining optimal designs of the proposed antennas.

Stacked patch antenna with folded patch feed for ultra-wideband application

A new stacked patch antenna with a folded patch feed is presented for ultra-wideband (UWB) application. The bandwidth is obtained by a stacked patch fed with a folded patch feed, and the size reduction is realised through the use of shorting wall. The antenna occupies a compact dimension of 0.340λ g ×0.340× g ×0.227× g (where λ g is the guided wavelength of the centre operating frequency). The design achieves an impedance bandwidth of 90% across the frequency range of 3.75%9.86%GHz. The details of the antenna designs are shown, and the results with low-profile characteristics make this antenna suitable for UWB applications.

Ultra wideband patch antenna with a novel folded-patch technique

The authors present the results of a polygonal patch antenna for ultra-wideband applications covering a frequency band from 4.14 to 13.50 GHz. The fabricated antenna achieved a 10 dB impedance bandwidth in excess of 125 with an antenna size of 0.373lambda o times0.373lambda o times0.149lambda o at its centre frequency. The antenna's impedance bandwidth is 64% higher than what is currently obtainable with state-of-the-art folded-patch techniques. The proposed patch antenna has a polygonal-shape with a rectangular slot and shorting pins. The analysis of this antenna shows that bandwidth broadening is achieved by using a rectangular slot on the patch that is fed from a folded-patch feed, whereas the reduction in antenna size is achieved through the use of two shorting pins strategically located on the radiating patch.

A Trapeizform U-Slot Folded Patch Feed Antenna Design Optimized With Jumping Genes Evolutionary Algorithm

A novel design of trapeizform U-slot folded patch feed antenna is presented in this paper. It is optimized by an evolutionary based optimization scheme which is capable of producing an antenna design that has a wide impedance bandwidth but small in dimension size. The optimized design was also experimentally verified by its hardware prototype in which 101.3% measured impedance bandwidth was obtained compared with its simulated bandwidth of 104%. Also, both the effectiveness of the optimization methodology and the proposed antenna configuration have been justified through comparison results.

A New Jumping Genes Paradigm for an E-Shaped Folded Patch Feed Antenna Design

A novel evolutionary computing algorithm, namely, jumping genes evolutionary algorithm (JGEA) is used for the optimization of antenna designs. This scheme incorporates with a multiobjective strategy that enables the gene mobility within the same chromosome, or even to a different chromosome. This type of horizontal gene movement causes the genes to find the suitable locations to achieve the necessary building blocks in such a way that the quality of nondominated solutions and/or the Pareto-optimal solutions can be enhanced. This new scheme is robust and provides outputs in speed and accuracy. It also generates a range of widespread extreme solutions. The design of an E-shaped patch antenna was adopted for the purpose of design demonstration. An antenna structure with 91% impedance bandwidth for a frequency range of 3.6–9.6 GHz was selected amongst the nondominated solutions set for the hardware fabrication. Its measured performances both for impedance bandwidth and frequency range were in good agreement with the simulated solution. The cross-polarized field was found to be small in comparison, and the copolarized field can sustain the broadside radiation pattern over the frequency band. This methodology of optimization can be of an alternative approach for antenna design.

Study of small wideband folded-patch-feed antennas

A small wideband patch antenna which exhibits an impedance bandwidth (Voltage Standing Wave Ratio (VSWR) ≤ 2) of more than 70% with an antenna size of 0.314λo×0.314λo×0.146λo (where λo is the guided wavelength of the centre operating frequency) is presented. Bandwidth broadening is achieved by an E-shaped patch fed by a folded-patch feed, whereas the size reduction is realised through the use of a shorting wall. As the antenna can be made from a single piece of copper plate, it is easier to fabricate than the wideband U-shaped-slot and L-shaped-slit folded-patch-feed antennas previously reported. Parametric studies of the proposed antenna are performed numerically to review its radiation mechanism. These include the purposes of having a shorting wall and two arms attaching on the upper patch forming the E-shaped pattern and the analysis of the input impedance of the antenna. Approximate equations for designing the proposed antenna are also presented. To verify the working principle, the proposed antennas are fabricated and tested for three different frequency bands. Stable radiation patterns are obtained across the band.

Study of slotted microstrip patch antennas with folded patch feed

A series of simulations and experimental investigations, of slotted microstrip patch antennas with a folded patch feed, are presented. The analysis includes the effects of varying the location of the feed and the shape of slot. All the investigated antennas are fed by a bandwidth-enhanced feeding method: folded patch feed. The folded patch feed is an attractive tailor-made feeding method for microstrip patch antennas, resulting in an impedance bandwidth (VSWR≤2) of more than 50%. In the study, the folded patch feed has been applied to different shapes of slots, and some of them profit with a wider impedance bandwidth over a rectangular U-slot shape. Among all the examined antennas, a trapezoidal slot microstrip patch antenna with an additional aperture and a shorting wall has an impedance bandwidth of 76.37%.

Study of a small wide-band patch antenna with double shorting walls

A small wide-band patch antenna with double shorting walls is presented. By employing two shorting walls and an additional aperture on the upper patch of a folded patch feed antenna, a 0.365/spl lambda//sub 0/ patch antenna with impedance bandwidth of more than 70% (VSWR/spl les/2) is achieved experimentally. Measured radiation patterns and gain across the frequency band are given.