Array Of Parasitic Patches Research Articles

A substrate-integrated waveguide-based wideband circularly polarized slot antenna using the parasitic square patch array

In this paper, a planar low-profile wideband circularly polarized substrate-integrated waveguide (SIW) based antenna is investigated. The antenna comprises two substrates stacked over each other. The top layer of the antenna is loaded with a 4 × 4 array of parasitic square patches stacked over a spiral slot loaded in the SIW cavity. The spiral slot is utilized for the generation of narrow band circular polarization and to enhance the CP bandwidth, the parasitic patch array is excited through the electromagnetic coupling mechanism without any air gap between them. The antenna is fabricated and tested to validate the simulated results. A wide relative impedance bandwidth of 33% (8.25–11.55 GHz) and the axial ratio bandwidth of 8.55–9.70 GHz (12.60%) is exhibited. The broadside radiation characteristics are achieved with peak gain of 8.05dBic at 9 GHz. The overall size of the antenna structure is 0.8λ0 × 0.8λ0. The proposed antenna is suitable for various satellite applications.

Characterization and performance enhancement of 4 × 4 microstrip antenna array in dusty atmosphere using metasurface based superstrate

The unique interaction between sand and wireless communication components in a dusty environment requires fundamental communication ideas that must be revisited from a different viewpoint. This paper introduces a 4 × 4 microstrip antenna array designed for a 24 GHz radar system, exhibiting high gain and a narrow beamwidth. A metasurface layer, employing a parasitic patch array, serves as a superstrate to enhance the array antenna’s performance and safeguard it against deterioration from direct contact with sand. The paper conducts a theoretical study on the sand model to assess the antenna’s performance in the sand environment, including an analysis of wave attenuation. The proposed antenna, loaded with the metasurface, demonstrates an impedance bandwidth from 23.08 to 24.9 GHz with a peak gain of 16.57 dBi. Evaluating its performance in various dusty atmospheres, the antenna proves effective in such environments, showing an impedance bandwidth of 23.04 to 24.73 GHz and a peak gain of 15.61 dBi. Additionally, the proposed antenna exhibits a minor phase shift in the main beam, with a half-power beamwidth of 15 degrees.

A Compact Millimeter-Wave Multilayer Patch Antenna Array Based on a Mixed CPW-Slot-Couple Feeding Network.

A compact Ka-band antenna array has been proposed to realize broadband and high gain for millimeter-wave applications. The antenna array is divided into a multilayer composed of a driven slot patch layer and a parasitic patch array layer, which is excited by a mixed CPW-Slot-Couple feeding network layer. According to characteristic mode analysis, a pair of narrow coupling slots are introduced in the driven patch to move the resonant frequency of characteristic mode 3 to the resonant frequency of characteristic mode 2 for enhanced bandwidth. In this article, a 1to4 CPW-Slot-Couple feeding network for a 2 × 2 driven slot patch array is implemented, and then each driven slot patch excites a 2 × 2 parasitic patch array. Finally, a proposed 4 × 4 × 3 (row × column × layer) Ka-band antenna array is fabricated to verify the design concepts. The measured results show that the frequency bandwidth of the antenna array is 25 GHz to 32 GHz, and the relative bandwidth is 24.5%. The peak gain is 20.1 dBi. Due to its attractive properties of miniaturization, broadband, and high gain, the proposed antenna array could be applied to millimeter-wave wireless communication systems.

Highly Efficient Dual-Beam Frequency Scanning Based on SSPPs With Parasitic Patch Array

A leaky-wave antenna (LWA) realizes radiation of travelling wave along guiding structures. Periodic modulation is an effective approach to turn non-radiating modes into radiating modes. A high-efficient LWA based on spoof surface plasmon polaritons (SSPPs) loaded with parasitic patch array is proposed. Sinusoidal modulation is used for the radiation of SSPPs, while parasitic array mitigates the open stopband (OSB) effect. A prototype is fabricated and measured. The measured and simulated results agree well with each other. Such design shows wide angle coverage of 83° from backward to forward and stable gain distribution of about 12 dB within the whole operating band.

Polarization Reconfigurable and Beam-Switchable Array Antenna Using Switchable Feed Network

A novel array antenna with reconfigurable polarizations and radiation pattern agility is presented in this paper. The digital-controllable array antenna has the functional capabilities of reconfigurable polarization and switching beam, which consists of cavity-backed antenna element based on substrate integrated waveguide (SIW) technique, parasitic patch array, power dividers and phase shifters. Polarization modes and radiation patterns can be dynamically controlled by means of Microcontroller Unit (MCU) with the different feeding ports and phase difference. To validate this proposal, the performance of the fabricated device was measured at the operating frequency of 5.4 GHz. Measured results indicate that the 10 dB impedance bandwidths and 3 dB axial ratio (AR) bandwidths cover from 5.25 to 5.6 GHz, and the measured gains range from 7.9 to 10.1 dBic. The experimentation and simulation verify that the proposed antenna can achieve two polarization states and five radiation beams of each polarization state, which indicate a good performance of the polarization reconfigurable and beam switching antenna array.

Low‐profile millimetre‐wave wideband microstrip antenna with parasitic patch arrays

A millimetre-wave low-profile wideband microstrip antenna is proposed. To widen impedance bandwidth and achieve stable large gain simultaneously, coplanar parasitic patch arrays are arranged on both sides of a microstrip patch fed by a coaxial probe. Double slots are etched on the microstrip patch to reduce H-plane cross-polarization levels. Zero-phase-reflection analysis with Floquet-port model is proposed to predict resonant frequency of the parasitic patch arrays. Resonance modes excited is verified according to input impedance with an ideal probe. Two adjacent broadside resonances respectively dominated by the quasi-TM10 mode of the microstrip patch and quasi-TM30 of the parasitic patch array are excited in turn. The proposed antenna with a dimension of 1.06 × 1.06 × 0.024 λ03 (λ0 is the wavelength of 29 GHz in free space) realizes 15% (27–31.35 GHz) impedance bandwidth for |S11| ≤ −10 dB. Realized peak gain is up to 9.26 dBi and 2-dB gain bandwidth is 15.7%. H-plane cross-polarization levels within 3-dB beamwidth are less than −14 dB, and back radiation levels are less than −17.9 dB.

Screen-Printed, Flexible, Parasitic Beam-Switching Millimeter-Wave Antenna Array for Wearable Applications

Millimeter wave antennas have applications in several sensing and communication systems. Such antennas, designed for modern miniaturized devices and systems, must be low profile, flexible, and low cost. Some applications also require beam steering for detection purposes. Combining all these features into an antenna system and delivering decent antenna performance is challenging. In this study, we combined a partially reflective surface with a parasitic patch array to create a simple beam-switching, low-profile, and flexible wearable detection system. To ensure lower costs as well as compatibility with wearable systems, screen printing was utilized on a flexible substrate. The antenna array was optimized for the 77 GHz band and had a high gain of 11.2 dBi. The designed system has three independent beams, which can be oriented from bore-sight to ±32° through a simple switching mechanism. The antenna array maintains its performance in both flat and flexed conditions. Finally, the antenna array was tested in the field to successfully detect objects moving in three different directions.

A low‐profile dual‐polarized multilayer parasitic patch array antenna with narrow air gap

AbstractThis article proposes a low‐profile dual‐linear polarized multilayer parasitic patch array antenna, which is composed of 3‐layer printed substrates and 1 air gap layer inserted between the lower and middle substrate. There is 1 slotted square patch printed on the lower substrate with 2 excited probes acting as feeding element, and 1 and 4 slotted square patches are on the middle and upper substrate respectively as parasitic elements. The stacked patches introduce additional dual‐polarized resonances for bandwidth enhancement. Specifically, the T‐ and rectangular slots and T‐stubs are employed near/on the orthogonal axis of the patches in order to achieve impedance matching and to improve 2 orthogonal polarizations. Furthermore, 6 stacked complementary split‐ring resonators (CSRRs) are loaded in the middle and upper substrate mainly for both impedance matching and port isolation adjustment. Simulated and measured results comply with each other, which shows that the fabricated antenna has an operational fractional bandwidth of 6.6% (2.34–2.5 GHz), a maximum gain of 7.9 and 6.9 dB at port 1 and 2 (while 10.2 and 9.3 dBi for the simulated ones), respectively, and port isolation better than 19 dB. In addition, the air‐gap thickness can be maintained at an extremely narrow level of 0.02λ0 (λ0 is the free‐space wavelength at the central frequency).

An array antenna based on coplanar parasitic patch structure

AbstractThis article presents a 5 × 5 array antenna with the coplanar parasitic patch structure. The array consists of 25 patches and 24 resonance branches. Two center patches, which are fed by two high frequency SMA probes, serves as the driving elements, while the surrounding 23 patches are the parasitic elements. The resonance branches of the array antenna are used as a feed network to transmit the coupling energy. As a result, 25 patches on the substrate can be stimulated simultaneously. The array antenna has a simple feed structure and compact size. Compared with a standalone antenna, the coplanar parasitic patch array antenna has the advantages of wide bandwidth and high gain. Experimental results show that the proposed antenna operating band is 17.2–21.3 GHz; the impedance bandwidth is 20.5%; and the peak gain is 14.2 dBi.

A Wideband Array Antenna With 1-Bit Digital-Controllable Radiation Beams

In this paper, we propose a $4\times 4$ low-profile wideband patch array antenna with radiation pattern agility. The digital-controllable antenna element is composed of a square driven patch, a $2\times 2$ parasitic patch array, and two switchable feeding ports, which are connected to a designed single-pole double-throw switch. Due to the symmetrical structure, individual excitation at the two feeding ports produces a 180° phase difference, giving rise to two basic digital elements of “0” and “1,” respectively. By switching the feeding ports for all antenna elements using a micro-controller unit, the radiation beam of the $4\times 4$ array antenna can be dynamically reconfigured. To validate the proposed concept, a prototype operating at 5.7 GHz with an overall size of $3.42\lambda _{0}\times 3.42\lambda _{0}\times 0.069\lambda _{0} (\lambda _{0}$ is the free-space wavelength at 5.7 GHz) was fabricated and measured. The measured 10-dB return loss bandwidths for all the states cover the frequency band of 5.12–6.32 GHz. The simulated and measured results show close agreement, which proves the powerful dynamical beam manipulation capability of the proposed array antenna.

High-gain waveguide slot antenna using simple parasitic patch's cover

In this article, a way based on using miniature patch cells has been proposed to increase gain and bandwidth of the waveguide slot antenna. In the presented approach, an array of 3 × 3 metal patches has been used as superstrate to create Fabry Perot theorem resonance cavity. The proposed high-gain and simple antenna is composed of a conventional waveguide slot antenna with an extended broad wall, and an array of parasitic patches which are symmetrically placed over slot at a distance of about free-space half wavelength. The slot has been created on a rectangular waveguide WR90 with 22.86 mm × 10.16 mm × 52.5 mm dimension, also extended wall dimension is 2λ0 (67.5 mm) × 3λ0 (107 mm). It has been shown that the proposed structure compared with the conventional waveguide slot antenna improves antenna peak gain from 6.5 to 16.5 dBi and, in the same time, antenna bandwidth from 11% to around 16.2%. More important advantage of the proposed antenna is that unlike to other Fabry Perot antenna with the same gain, there is not any dielectric material in the proposed structure. A prototype antenna was simulated, fabricated, and measured for verification.

Fluidic beam steering in parasitically coupled patch antenna arrays

A technique for designing a parasitic patch antenna array whose beam can be steered dynamically using a fluidic tuning mechanism is presented. Using this technique, a three-element patch antenna array operating at 5 GHz is designed and fabricated using 3D printing. Two oil-filled channels are placed in the substrate of the antenna along the radiating edges of the patches and filled with movable metal cylinders and glass balls. The parasitic elements are mutually coupled to the centre element in the H-plane. As the train of metal cylinders and glass balls are moved from the left or right with respect to the centre-driven patch element, the beam is steered towards the opposite direction. The proposed parasitic patch array is able to steer the beam ±22.5° with maintained impedance matching.

A Ka-Band Multi-Layer Parasitic Patch Array Antenna Using Low-Temperature Co-Fired Ceramic Technology

An aperture-coupled multi-layer parasitic patch array antenna operating at the Ka-band has been developed based on low-temperature co-fired ceramic technology. E-shaped parasitic patches are employed to direct the antenna radiation toward the broadside direction, thus improving the gain. Meanwhile, the parallel slots in the parasitic patches excite multiple resonant modes to broaden the bandwidth. The antenna shows a measured 10-dB impedance bandwidth of 28% (31.1 to 41.2 GHz) with a gain of >6 dBi at 31 to 38 GHz. A mutual coupling of <−18 dB is measured between adjacent elements with a center-to-center spacing of 6 mm (0.7λ0 at 35 GHz). A two-element array was also developed, which exhibits a measured 10-dB impedance bandwidth of 26% (31.5 to 40.7 GHz), as well as a gain >8.8 dBi at 31 to 37 GHz and a peak gain of 9.7 at 36 GHz. The proposed antenna achieves wide bandwidth and relatively high gain, which is suitable for millimeter-wave radars and high data-rate communication systems.

Effect of superstrate material on a high‐gain antenna using array of parasitic patches

AbstractThis article highlights the effect of superstrate material on a high‐gain antenna using array of parasitic patches for wireless applications. The antenna structure consists of a microstrip antenna, which feeds an array of square parasitic patches fabricated on a ceramic or FR4 superstrate. The patches on a superstrate are suspended in air at λ0/2. The spacing between parasitic patches and patch dimensions decrease with dielectric constant and, thus, a compact antenna with almost same gain can be designed with high dielectric superstrate. The structures with 5 × 5 array of square parasitic patches provide a gain of 17.5 dB on infinite ground plane in both the cases but the array dimension is 55 × 55 mm2 in ceramic as compared to 115 × 115 mm2 Antenna with ceramic superstrate on finite ground requires 25% less ground plane size as compared to FR4. Structure with FR4 superstrate is designed, fabricated, and tested. The measured VSWR is &lt;2 over 5.725–5.875 GHz frequency band. The antenna with 5 × 5 array of square parasitic patches provides a gain of 18.0 dB with 92% efficiency, SLL of −18.4 dB, and front to back lobe ratio of more than 20 dB. The proposed structure can be packaged inside an application platform. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 82–88, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24850

Low cost efficient high gain antenna using array of parasitic patches on a superstrate layer

AbstractThis article proposes a low cost efficient high gain antenna using array of parasitic patches for wireless applications. The antenna structure consists of a microstrip antenna which feeds an array of square parasitic patches fabricated on a low cost FR4 superstrate. The patches on superstrate are suspended in air at λ0/2. The structure with 5 × 5 array of square parasitic patches is designed, fabricated, and tested. The measured voltage standing wave ratio (VSWR) is &lt;2 over 5.725–5.875 GHz frequency band. The antenna with a single square patch provides a gain of 12.6 dB, whereas the antenna with 5 × 5 array of square parasitic patches provides a gain of 18.0 dB with 92% efficiency, SLL of −18.4 dB and front to back lobe ratio of more than 20 dB. The proposed structure can be packaged inside an application platform. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 733–739, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24156

Diversity Measurements of a Reconfigurable Antenna With Switched Polarizations and Patterns

A reconfigurable parasitic patch array is designed to provide polarization and pattern diversities. The performance of the device is predicted using a commercial simulator including a pin diode modelling and an optimization procedure of the switched loads based on an equivalent flow graph. Measurements of the correlation factor and the diversity gain in an indoor environment are performed with a dedicated platform for two orientations of the antenna.

Use of the FDTD method in the design of microstrip antenna arrays

AbstractThe finite‐difference time‐domain (FDTD) method is a widely used numerical technique for computer‐aided design (CAD) of printed antennas and arrays. This technique can accurately predict performance characteristics of complex microstrip antennas, including the effects of parasitic elements and aperture‐coupled feeds. In the case of arrays, mutual coupling effects between closely packed elements can also be modeled. This article will examine the advantages and limitations of the FDTD method for CAD of microstrip arrays. Calculated results are compared with experiment for a 3‐patch coplanar parasitic patch array.