Parasitic Antenna Array Research Articles

Design of shorted parasitic rhombic array antenna for 24 GHz rear and side detection system

A novel microstrip patch antenna is proposed for automotive application. The antenna design has been investigated through both the parametric study and the demonstration of surface currents on the antenna structure. The surface currents related to the co-polarisation increased, and those related to the cross-polarisation is reduced by attaching shorted parasitic element. The four types of single antenna are designed to compare of gain and cross-polarisation level. The cross-polarisation level of proposed antenna has been reduced by 5.9 dB compared with the rhombic antenna. The rhombic array antenna and proposed array antenna were fabricated and tested for input reflection coefficient and radiation performance. The measured and simulated results have been presented and discussed.

Design of a Super Directive Four-Element Compact Antenna Array Using Spherical Wave Expansion

In this paper, a super directive four-element compact parasitic antenna array has been designed and optimized using an ad hoc procedure based on the Harrington maximum directivity definition and spherical wave expansion. The complete design procedure (i.e., calculation of the optimum excitation coefficients and equivalent impedance loads associated to each parasitic element) is presented and validated through full-wave electromagnetic simulations. The proposed array has been designed at 868 MHz; its electrical size is $0.45 \lambda_0 \times 0.36 \lambda_0$ (diameter of minimum sphere circumscribing the antenna equal to $0.57 \lambda_{\bm{0}}$ ). A prototype has been built and tested to demonstrate the effectiveness of this design. A maximum directivity of 11.7 dBi has been measured at 871 MHz in satisfactory agreement with theoretical results and electromagnetic simulations.

In brief

PAGE 1222 A team working in Malaysia have developed a compact metamaterial antenna for ultra wideband applications. The antenna uses four metamaterial unit cells that show both negative permeability and negative permittivity, which allows the antenna to operate with a peak gain of 8.57 dBi. The antenna has an operating range of 3.07 GHz to 19.91 Ghz. PAGE 1229 A technique for designing a parasitic patch antenna array with a beam that can be steered dynamically is presented by a team working in the USA. The team fabricated a three element patch antenna array operating at 5 GHz, which uses a system of oil filled channels filled with movable metal cylinders and glass balls to steer the beam ±22.5°. The metamaterial structure allows the antenna to be compact while maintaining its performance PAGE 1286 A team working in China have fabricated high performance, fully transparent, bottom gate type calcium-doped zinc oxide thin film transistors on glass substrate. The team investigated the impact that substrate temperature had during active layer deposition on the electrical properties of the transistors. The antenna was fabricated using 3D printing PAGE 1251 A team working in the UK present their work on pedestrian motion tracking. To address the problems of abrupt changes in motion and delays in the tracking process, the team use a method based on simulations of the uncertainty of an electron's position around the nucleus. This allows tracking of abrupt motions with low delay. The team found a large improvement in transistors fabricated using the optimum temperature PAGE 1277 Photonic crystal cavities with a high Q factor of 200,000 have been produced using deep ultraviolet lithography. The team, from the UK, say that restrictions have prevented the realisation of high Q factor optical resonators. The team think the advance could help the mass-production of ultra-compact nanophotonic devices. The method propagates particles in areas a person is most likely to be Deep Ultraviolet Lithography is essential for the mass production of silicon devices

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.

저가 3차원 빔 조향을 위한 단일급전 마이크로스트립 기생배열 안테나

저가 3차원 빔 조향을 위한 단일급전 마이크로스트립 기생배열 안테나

Design of a closely‐spaced, multiple‐element parasitic antenna array

ABSTRACTA new design of a closely‐spaced, multiple‐element parasitic antenna array is proposed based on the identified dominant surface wave mechanism. The optimum surface wave phase velocity, which leads to the maximum antenna gain, is determined for a fixed length array. The antenna input impedance is presented and optimized using folding technique. Both numerical simulations and measurements are implemented. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2374–2377, 2014

Theory of ESPAR Design With Their Implementation in Large Arrays

A generalized formulation as well as a simple design approach is presented for electronically steerable parasitic array radiators (ESPAR). Based on the presented design procedure, a low-cost rectangular dielectric resonator parasitic phased array antenna is designed. An E-plane linear dielectric resonator phased array coupled to symmetric narrow slot apertures is investigated. The driven element is mutually coupled to the parasitic elements and reactive loads are utilized to control the phase to achieve a particular beam scanning direction. The use of low-cost reactive loads instead of expensive conventional phase shifters allows for more economic fabrication. Based on this design, a five elements planar array is designed and measured. In addition, a large array using ESPAR subarrays is presented.

Design of a Dual-Band, Electrically Small, Parasitic Array Antenna

A new design of an electrically small parasitic array antenna to obtain dual bands is suggested. The antenna comprises a driver and two directors, where all elements are bent in rectangular shapes to reduce the antenna size. Two resonances nearby each other are achieved by twisting vertical segments into helical shapes, starting from the ground of both directors. The overall volume of the antenna is 18.0 mm (0.099λ)×21.0 mm (0.116λ) ×21.4 mm ( 0.118λ), and the electrical size, kr, is 0.8. The maximum realized gains in the director direction are greater than 8.4 dBi at both resonant frequencies.

A Single RF MIMO Loading Network for High-Order Modulation Schemes

Recently, a novel MIMO transmitter architecture has been introduced that requires only a single radio-frequency (RF) chain and is built on parasitic antenna arrays. MIMO transmission in this case is achieved by shaping directly the radiation pattern with the aid of analog tunable loads attached to the parasitics. As it has been shown, such a single RF MIMO system can support all PSK modulation formats with purely imaginary loading values. This paper extends its capabilities and proposes a novel architecture for parasitic antennas that is able to providecomplexloading values, even with a negative real part. Definitely, this will extend the flexibility of parasitic antennas to multiplex successfully over the air more complex signaling formats, for example, QAM signals. The bit error rate evaluation shows that the proposed architecture could be very promising in emerging devices and also illustrates its robustness under possible loading perturbations that might have been raised due to nonidealities in the design.

Triple Band Parasitic Array Antenna for C-X-Ku-Band Application Using Out-of-Phase Coupling Approach

Triple band parasitic array antenna for C-X-Ku-band application is presented. The proposed antenna is designed using the concept of parasitic array and out-of-phase coupling approach. The objects of research are to optimize total inductance of geometry by using out-of-phase inductance approach. The out of phase inductance of geometry consists of using two U-patches novel director on the left side of geometry, appropriate dimension of ground plan, and gap coupling between parasitic and active patches. The dimension of the ground plan geometry is 0.5λ mil × 0.5154λ mil. The usable impedance bandwidth of design antenna is “5.8 GHz to 18 GHz” (102% impedance bandwidth) and gain enhancement is up to 11.8 dBi. The proposed antenna can be used for X-Ku band and C-band applications. Both simulated and measured results are presented, which are in good agreement. The proposed antenna was fabricated with a thin copper layer printed on a thin lossy FR4 substrate for low-cost production.

A Novel Planar Parasitic Array Antenna With Frequency- and Pattern-Reconfigurable Characteristics

A novel planar parasitic array antenna with reconfigurability in both frequency band and radiation pattern is proposed. It consists of six symmetrically reconfigurable radiating elements and six symmetrically reconfigurable parasitic elements. RF p-i-n diodes are used to switch the radiation structure and change the current distribution, which leads to 12 different radiation patterns and two frequency bands within 2.28-2.58 and 2.62-2.73 GHz, respectively. A good agreement between the measured and simulated results finally validates the proposed antenna.

A 900 MHz Beam Steering Parasitic Antenna Array for Wearable Wireless Applications

A 900 MHz wearable beam steering antenna array is proposed. A wideband driven dipole when assisted by several varactor diode controlled parasitic dipoles allows the array beam to be steered in the azimuth. Antenna array prototypes fabricated using copper, conductive fabrics and conductive threads show good bandwidth and radiation performance. The array when placed against an anatomically correct human body model shows that the array beam can be steered along 3 distinct angles, 0, 45, and 315 degrees with 5.9 dBi peak gain.

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.

Method of MIMO Channel Estimation Between Parasitic Antenna Arrays

This paper proposes a channel estimation method between parasitic antenna arrays that have no radio frequency (RF) frontends. The multiple-input multiple-output channel exceeding the number of the RF frontends can be defined if the parasitic antennas are used in both the transmitting and receiving array antennas. The channel between parasitic antenna arrays can be estimated by varying the tunable reactance elements at the parasitic antennas. Based on the simulation and experiment, the channel estimation is demonstrated and its accuracy is studied.

Parasitic Array Antenna With Enhanced Surface Wave Launching for On-Body Communications

This paper presents a novel planar directive antenna array with enhanced coupling to the surface wave on the human body. Coupling of a small wearable antenna into the Norton surface wave and creeping wave modes on the surface of the human body is first discussed. Based on these observations, the surface wave parasitic array (SWPA) antenna was designed, and parametric studies were performed to optimize the antenna directivity on the body phantom surface. The antenna was fabricated and measured. Its performance was tested by path gain simulations and measurements. The measurements were performed on a liquid phantom inside an anechoic chamber. Comparison of the performance of the new antenna with other antennas is also presented.

A New Class of Antenna Array With a Reconfigurable Element Factor

A parasitic layer-based multifunctional reconfigurable antenna array (MRAA) formed by the linear combination of four (4 × 1) identical multifunctional reconfigurable antenna (MRA) elements is presented. Each MRA produces eight modes of operation corresponding to three steerable beam directions (θ <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">xz</i> =-30 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">°</sup> , 0 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">°</sup> , 30 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">°</sup> ) with linear and circular polarizations in <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</i> - <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">z</i> plane and another two steerable beam directions (θ <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">yz</i> =-30 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">°</sup> , 30 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">°</sup> ) in <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</i> - <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">z</i> plane with linear polarization. An individual MRA consists of an aperture-coupled driven patch antenna with a parasitic layer placed above it. The surface of the parasitic layer has a grid of 4 × 4 electrically-small rectangular-shaped metallic pixels. The adjacent pixels can be connected/disconnected by means of switching resulting in reconfigurability in beam-direction and polarization. A 4 × 1 linear MRAA operating in the ~ 5.4-5.6 GHz is formed by the optimized MRA elements. MRA and MRAA prototypes have been fabricated and measured. The measured and simulated results agree well indicating ~ 13.5 dB realized array gain and ~ 3% common bandwidth. The MRAA presents some advantages as compared to a standard antenna array: MRAA alleviates the scan loss inherit to standard antenna arrays, provides higher gain, does not need phase shifters for beam steering in certain plane, and is capable of polarization reconfigurability.

Reconfigurable Orthonormal Basis Patterns Using ESPAR Antennas

Beamspace multiple-input-multiple-output (BS-MIMO) systems with reduced hardware complexity have been recently considered in the literature. So far, BS-MIMO research effort focuses on the development of efficient single-RF MIMO transmission schemes based on parasitic antenna arrays. Single-RF BS-MIMO systems can provide both multiplexing and beamforming capabilities by exploiting the available aerial degrees of freedom of the radiated field while maintaining low space and complexity requirements. Previous studies used electronically steerable passive array radiators (ESPARs) for the multiplexing of multiple data streams utilizing an ESPAR-specific set of orthonormal basis patterns. However, these basis patterns ensure orthogonal transmission of the multiple streams in idealistic rich scattering environments. In this letter, a novel technique is developed for the adaptive selection of the most effective basis patterns in both transmitter and receiver sides based on the actual wireless channel propagation conditions maximizing the system capacity.

DESIGN OF A PRINTABLE, COMPACT PARASITIC ARRAY WITH DUAL NOTCHES

A compact, parasitic array antenna printed on both sides of the substrate to generate dual notches is introduced. The antenna is composed of one driver and two directors. Both directors are discretely segmented and are twisted with each other to minimize the radiation interference from one director to the other at each resonance. The antenna is optimized for realized gains in the director direction at the two resonant frequencies. The optimized antenna has been fabricated and measured to verify the simulated results. At both resonances, the measured realized gains in the director direction are greater than 8.5dBi, and the front-to-back ratios are more than 10dB.

FET 스위치를 이용한 2.6 GHz 용 SPA 안테나 설계

본 논문에서는 펨토셀에서 기기 간의 상호 간섭을 해결하기 위해 2.6 GHz Wimax 밴드용 switched parasitic array(SPA) 안테나를 설계하였다. 설계한 SPA 안테나는 방사체(radiator)로 동작하는 단일 급전 <TEX>${\lambda}/4$</TEX> 모노폴 안테나가 중앙에 있고, 스위칭에 따라 반사체(reflector)와 유도체(director)로 동작하는 4개의 기생소자가 이를 둘러싸고 있으며, 이들 기생소자는 개방된 모노폴이 각각 둘러싸고 있다. 본 논문에서는 기존의 PIN 다이오드가 아닌 RF FET 스위치를 사용하여 빔 조향을 함으로써 간단한 구조의 저가, 저전력 안테나를 설계하였으며, 스위치의 특성에 따른 SPA 안테나의 성능을 분석하였다. 제작한 안테나의 크기는 반지름 65 mm, 높이 35 mm이고, 2.6 GHz에서 전후방비가 15 dB 이상이며, 스위칭에 따라서 8방향으로 빔 조향이 가능하다. In this paper, a 2.6 GHz switched parasitic array(SPA) antenna is designed to resolve the device interference in the femtocell. The designed SPA antenna structure consists of a central <TEX>${\lambda}/4$</TEX> monopole antenna as a radiator and surrounding four parasitic elements operating as a reflector or a director depending on the switching state. In addition, open state monopoles around the parasitic elements are placed to improve the directivity. The designed antenna utilizes RF FETs as switching elements instead of conventional PIN diodes, which enables beam steering with a simple structure consuming low power. To select the proper FET switch, the performance of the SPA antenna depending on the switch characteristics is analyzed. The fabricated antenna has 65 mm radius and 35 mm height, which shows about 15 dB front-back-ratio(FBR) at 2.6 GHz and enables eight-directional beam steering.

Design of an Electrically Small, Circularly Polarized, Parasitic Array Antenna for an Active 433.92-MHz RFID Handheld Reader

An electrically small, two-element, parasitic array (Yagi) antenna is proposed for an active 433.92-MHz RFID handheld reader. The antenna is composed of a square-shaped driver and director. The circular polarization is achieved by pulling the driver and pushing the director at one side. The sense of the antenna can be changed easily by pushing the driver and pulling the director at the same side. The total volume of the antenna is 115 mm × 115 mm × 13.8 mm (0.166 λ × 0.166 λ × 0.02 λ), and the electrical size is a <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">kr</i> of 0.75. The maximum measured realized gain is 3.5 dBic.