Low-cost Antenna Research Articles

UWB Wire-Bowtie Array for FM-PCL Passive Radar

Passive coherent location (PCL) systems using commercial FM radio broadcast stations as illuminators of opportunity (FM-PCL) require an antenna system with a null in its radiation pattern for suppressing the direct path interference (DPI) from the selected FM broadcast station. To maximize the surveillance coverage of the FM-PCL, ideally, the antenna should have a cardioid radiation pattern, which can be obtained by the ideal couplet of isotropic radiators. We carry out a theoretical and experimental analysis to show that such a cardioid pattern cannot be realized by a couplet of cylindrical wire antennas. Therefore, we introduce an alternative array configuration and at the same time seek a simple and low-cost antenna solution for FM-PCL. The proposed antenna is a two-element array of UWB wire bowties, which has an ultrawide bandwidth, a stable main beam, a large beamwidth, and a fixed array setup within the FM-PCL frequency range (88–108 MHz), leading to a simple antenna implementation. At the same time, as it does not require expensive RF and mechanical parts, a low-cost antenna solution for FM-PCL is obtained. Hence, the proposed antenna satisfactorily meets the goal of this work, i.e., simple and low-cost antenna solution for the FM-PCL passive radar.

A Low-Cost Antenna Using SISL Technology With Suppressed Sidelobe Level for 77 GHz Automotive Radar

The letter proposes a substrate integrated suspended line low-cost antenna with suppressed sidelobe levels for 77 GHz automotive radar. The antenna consists of two embedded air cavities. The double-layer wiring with dielectric excavation makes more electromagnetic energy distributed in the air cavity, significantly reducing the dielectric loss. The sidelobe level is decreased to −15 dB according to the Chebyshev synthesis. The measured results validate that the antenna bandwidth is from 75.01–82.12 GHz which can cover the 77 GHz application (76–81 GHz) with the max realized gain of 13.5 dBi. In addition, the antenna is fabricated on the FR4 substrates resulting in low cost.

High gain low-cost antenna based on the utilization of diffracted fields from semi-ring shape dielectric edges

A simple antenna with a 20-dBi gain is proposed. A thorough analysis of the propagation mechanism accompanied by a unique physical insight is provided. The realized structure has a low profile, low-cost, and compact features. A detailed insight into applying the Fresnel–Huygens principle is provided.

Wideband and High-Gain Substrate Integrated Folded Horn Fed Open Slot Antenna

This article presents a novel substrate-integrated folded horn-fed open slot antenna with wide bandwidth and high gain for millimeter-wave (mmW) applications. The antenna has a three-layer planar structure, including a pair of open slot radiators and two substrate-integrated H-plane horns (SIHs) that are incorporated as the feed to generate quasi-TEM wave excitations. A folded SIH structure is introduced, which reduces the antenna size by 37%. To improve the gain and radiation patterns, the proposed antenna is designed with differentially fed excitations. The measured results validate that the antenna achieves a wide impedance bandwidth of 54.4% from 52.3 to 91.4 GHz and a peak gain of 16.3 dBi. Meanwhile, the radiation patterns are stable throughout the operating bandwidth with low cross-polarization, sidelobe, and back lobe levels. The proposed wideband, high-gain, planar, and low-cost antenna is an attractive candidate for mmW applications.

A Field Calibration Solution to Achieve High-Grade-Level Performance for Low-Cost Dual-Frequency GNSS Receiver and Antennas.

Low-cost dual-frequency receivers and antennas have created opportunities for a wide range of new applications, in regions and disciplines where traditional GNSS equipment is unaffordable. However, the major drawback of using low-cost antenna equipment is that antenna phase patterns are typically poorly defined. Therefore, the noise in tropospheric zenith delay and coordinate time series is increased and systematic errors may occur. Here, we present a field calibration method that fully relies on low-cost solutions. It does not require costly software, uses low-cost equipment (~500 Euros), requires limited specialist expertise, and takes complex processing steps into the cloud. The application is more than just a relative antenna calibration: it is also a means to assess the quality and performance of the antenna, whether this is at a calibration site or directly in the field. We cover PCV calibrations, important for deformation monitoring, GNSS meteorology and positioning, and the computation of PCOs when the absolute position is of interest. The method is made available as an online web service. The performance of the calibration method is presented for a range of antennas of different quality and price in combination with a low-cost dual-frequency receiver. Carrier phase residuals of the low-cost antennas are reduced by 11–34% on and 19–39% on , depending on the antenna type and ground plane used. For the cheapest antenna, when using a circular ground plane, the residual is reduced from 3.85 mm before to 3.41 mm after calibration, and for from 5.34 mm to 4.3 mm. The calibration reduces the Median Absolute Deviations (MADs) of the low-cost antennas in the vertical direction using Post Processed Kinematic (PPK) by 20–24%. For the cheapest antenna, the MAD is reduced from 5.6 to 3.8 mm, comparable to a geodetic-grade antenna (3.5 mm MAD). The calibration also has a positive impact on the Precise Point Positioning (PPP) results, delivering more precise results and reducing height biases.

Dual-Polarized Antenna With Dual-Differential Integrated Feeding for Wideband Full-Duplex Systems

A new two-port dual-polarized planar antenna with an integrated feeding circuit for in-band full-duplex (FD) (IBFD) applications is presented. The antenna consists of four H-shape slots, stacked patches for enhanced bandwidth (BW), and a separate layer of two differential (0° and 180° split) power dividers connected using vertical transmission lines which define the feeding system. The multilayer antenna is well matched from about 2.2 to 2.5 GHz with isolation values from about 40 to 60 dB. When compared to similar IBFD antenna systems, the proposed configuration provides a higher isolation BW (10%) and higher gain (7.8 dBi) whilst adopting a simple feeding network. Also, by using the proposed feeding circuit, the manufactured antenna does not require any external cables and couplers. This simplifies the structure and reduces the number of cable connections. This allows for other analog-based self-interference reduction schemes for further improvements in the transmit and receive data link. In addition, the proposed antenna design was extended to a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$4 \times 1$ </tex-math></inline-formula> array. These dual-differential IBFD antenna systems are a good alternative to more conventional FD designs which typically require external coupler-based feeding. In addition, the operating BWs and isolation values offered by these S-band systems can support new data link possibilities for beam steering and future IBFD wireless networks by low-cost antenna and feeding circuit integration.

Dual Band GNSS Antenna Phase Center Characterization for Automotive Applications

High-accuracy Global Navigation Satellite System (GNSS) positioning is a prospective technology that will be used in future automotive navigation systems. This system will be a composite of the United States' Global Positioning System (GPS), the Russian Federation's Global Orbiting Navigation Satellite System (GLONASS), China Beidou Navigation Satellite System (BDS) and the European Union’s Galileo. The major improvement in accuracy and precision is based on (1) multiband signal transmitting, (2) carrier phase correction, (3) Real Time Kinematic (RTK). Due to the size and high-cost of today’s survey-grade antenna solutions, this kind of technology is difficult to use widely in the automotive sector. In this paper, a low-cost small size dual-band ceramic GNSS patch antenna is presented from design to real sample. A further study of this patch antenna illustrates the absolute phase center variation measured in an indoor range to achieve a received signal phase error correction. In addition, this low-cost antenna solution is investigated when integrated into a standard multi-band automotive antenna product. This product is evaluated both on its own in an indoor range and on a typical vehicle roof at an outdoor range. By using this evaluation file to estimate the receiver position could achieve phase motion error-free result.

A Dual-Band and Low-Cost Microstrip Patch Antenna for 5G Mobile Communications

This paper investigates the numerical and experimental analysis of a low-cost and dual-band microstrip patch antenna for the fifth generation (5G) mobile communications. The numerical analysis of the proposed antenna is performed using the computational electromagnetic simulator (CEMS) software which is based on the finite-difference time-domain (FDTD) and CST software which is based on the finite integration technique (FIT). The performance of the proposed antenna designed and fabricated on a low-cost FR-4 substrate is verified with the simulated and measured results. The antenna operates at dual frequency bands which are 24 and 28 GHz. The antenna maximum gain values are 3.20 dBi and 3.99 dBi in the x-y plane at 24 and 28 GHz, respectively. The proposed antenna provides almost omni-directional patterns suitable for 5G mobile communication devices.

High gain antenna for n260- & n261-bands and augmentation in bandwidth for mm-wave range by patch current diversions

PurposeA compact low-cost antenna structure is proposed to augment the impedance-bandwidth in mm-wave range. Beside it, the paper also aimed to enhance high gain for n260 and n261-bands, suitable for futuristic communication systems.Design/methodology/approachDesign consists of radiating patch and a partial ground plane with semi-circle arc for smooth flow of current. The lower corners of patch are gradually clipped away to make the patch nearly elliptical. Further, two tilted slots at an angle α = 15° are etched at the edges of the patch to augment bandwidth for mm-wave range. These slots divert the periphery current of semi elliptical patch towards center portion of antenna which ensures the participation in radiation of central portion of patch. The upper corners are also clipped away to limit the copper losses and smoothly flow of current. The proposed antenna is designed using HFSS and it is structured on inexpensive FR4 substrate of size 27.5 × 20 mm2.FindingsIt supports enormous −10 dB bandwidth of 5.86–40GHz (148.89%) even though use of high loss-tangent material and high gain for 28 GHz (27.50–28.35 GHz) n261–band and 37 GHz (37–38.6 GHz) and 39 GHz (38.6–40GHz) n260–bands with a peak-gain of 8.76 dBi, 10.8 dBi and 9.92 dBi, respectively.Originality/valueThe proposed methodology of design is very useful to enhance impedance bandwidth to cover all C–, X–, Ku–, K– and Ka–band even though use of low cost material with high loss tangent. In recent literature, the designs were implemented with a costly material and having very low loss tangent and covers partial suggest bands.

Performance Evaluation of Low-Cost Multi-Frequency GNSS Receivers and Antennas for Displacement Detection

Low-cost Global Navigation Satellite System (GNSS) receivers are currently used in various engineering applications. These low-cost devices are regarded as suitable sensors for applications in areas with a high risk of instrument damage. The main objectives of this research were to identify the size of displacements that can be detected in relative and absolute positioning modes by low-cost GNSS instruments and to compare the results of selected antennas. Additionally, geodetic and low-cost GNSS instruments were compared in the level of observations. For this study, low-cost SimpleRTK2B V1 boards, which house ZED-F9P GNSS chips, and three low-cost antennas, namely, Survey, Tallysman TW3882, and Survey Calibrated, were selected. While antenna calibration parameters are known for the last antenna, this is not the case for the first two. For testing purposes, a geodetic network consisting of four points was established; horizontal and vertical movements were imposed by a special mechanism with high accuracy. In relative positioning mode, the results indicate that the Survey Calibrated antenna can detect horizontal and vertical displacements with sizes of 4 mm, and 6 mm, respectively. In the detection of horizontal displacements, the performance of the Survey antenna was not as good as that of Tallysman, and the sizes of detected displacements were 6 mm and 4 mm for the first, and second antennas, respectively. Vertical displacements of 9 mm were detected using both Survey and Tallysman antennas. In absolute positioning mode, Survey Calibrated also had better performance than the Tallysman antenna, and spatial displacements of 20 mm or greater were detected by low-cost GNSS instruments. The observations made with low-cost and geodetic GNSS instruments were compared, and the latter showed better performance. However, the differences in cycle slips and the noise of phase observations were inferior. Considering their cost and proven performance, it can be concluded that such sensors can be considered for setting up a highly accurate but low-cost geodetic monitoring system.

Antenna Design and Fabrication with Circular Microstrip Patch: A Review

The paper presents a review on antenna designing and fabrication techniques with Microstrip Patch (MSP) development. The requirements of MSP are remote controlling, mobile communication, space communication and all wireless communication areas. Aim of this development is to provide a new approach of the designing and simulation of circularMSP for 5.8 GHz operating frequency. CST MICROWAVE STUDIO (MWS) facilitates the quick and accurate analysis of high frequency (HF) antennas which gives the responses and results before fabrication of actual patch with complete technology for 3D EM. FR-4 glass epoxy material board is used for fabrication which is admired and adaptable highpressure thermoset plastic laminate grade with superior strength to weight ratios. Circular MSP is easy to fabricate, portable, lightweight and low cost antenna. N9923A Field Fox RF VNA (Vector Network Analyser) were used for studying and testing all the parameters of fabricated MSP.

Precise water level measurements using low-cost GNSS antenna arrays

Abstract. We have developed a ground-based Global Navigation Satellite System Reflectometry (GNSS-R) technique for monitoring water levels with a comparable precision to standard tide gauges (e.g. pressure transducers) but at a fraction of the cost and using commercial products that are straightforward to assemble. As opposed to using geodetic-standard antennas that have been used in previous GNSS-R literature, we use multiple co-located low-cost antennas to retrieve water levels via inverse modelling of signal-to-noise ratio data. The low-cost antennas are advantageous over geodetic-standard antennas not only because they are much less expensive (even when using multiple antennas in the same location) but also because they can be used for GNSS-R analysis over a greater range of satellite elevation angles. We validate our technique using arrays of four antennas at three test sites with variable tidal forcing and co-located operational tide gauges. The root mean square error between the GNSS-R and tide gauge measurements ranges from 0.69–1.16 cm when using all four antennas at each site. We find that using four antennas instead of a single antenna improves the precision by 30 %–50 % and preliminary analysis suggests that four appears to be the optimum number of co-located antennas. In order to obtain precise measurements, we find that it is important for the antennas to track GPS, GLONASS and Galileo satellites over a wide range of azimuth angles (at least 140∘) and elevation angles (at least 30∘). We also provide software for analysing low-cost GNSS data and obtaining GNSS-R water level measurements.

Performance Comparison of Microstrip Patch Antenna Using h-BN Nanoceramic Substrate and FR4 Substrate

The recent communication receiver requires compact size, low cost, less weight and high-performance antenna for broadband applications. This paper compares the performance of the microstrip patch antenna designed using h-BN nano ceramic substrate with antenna designed using FR4 substrate. In this proposed new substrate is developed using powder metallurgy principle. Simulated and experimental results shows that proposed substrate for patch antenna in S-band applications achieve good resonance at two different frequencies 2.2 and 2.6 GHz with reflection coefficient of −35 and −40 dB respectively. Same antenna structure using FR4 structure is achieving good resonance at multiple frequency and broadband characteristics in C-band and X-band of the radio spectrum.

Performance Analysis of a GNSS Multipath Detection and Mitigation Method With Two Low-Cost Antennas in RTK Positioning

Global navigation satellite system (GNSS) plays a vital role in high-precision positioning whereas detecting and mitigating carrier phase multipath error is still a significant challenge. Multipath error is closely related to the users&#x2019; environment, so it is difficult to mitigate by traditional differencing techniques. In this paper, we discuss the possibility and potential performance of multipath detection and mitigation with low-cost antennas in real-time kinematic (RTK) positioning. We employ two low-cost antennas and assume that the baseline length is known. We employ the carrier phase, ephemeris, and baseline length to detect the observed and estimated baseline vectors&#x2019; consistency in real-time. A reasonable threshold is proposed to detect the satellite signals with the multipath effect, then we eliminate these signals and use the remaining satellite signals for RTK positioning to mitigate multipath. The experiments are carried out in the open environment without multipath and the environment with specular multipath. Experimental results show that the false alarm rate of this method is entirely consistent with the theoretical value. When the number of satellites is six and eight, this method can reduce the RMS (root mean square) of positioning error by approximately 64&#x0025; and 49&#x0025;, respectively. At the same time, this method can improve the ambiguity success rate to above 99&#x0025;.

Wideband hyperbolic flat lens in the Ka-band based on 3D-printing and transformation optics

A flat wideband lens antenna operating in the Ka band is presented. The design corresponds to the transformation of a hyperbolic lens via quasi-optic transformation into a flat lens. The implementation of the lens is made using 3D printing technology as it allows cheap and precise manufacturing of the complicated shapes obtained with the transformation. The required refractive indices are calculated and implemented with varying infill percentages of the used filaments in each transformed layer. The experimental results show excellent agreement with the simulations, including low losses. The presented design is a low-cost antenna with the measured gain above 23 dBi in the whole Ka band (26.5–40 GHz).

Testing the Performance of Multi-Frequency Low-Cost GNSS Receivers and Antennas.

Global Navigation Satellite System (GNSS) low-cost multi-frequency receivers are argued as an alternative to geodetic receivers for many applications. Calibrated low-cost antennas recently became available on the market making low-cost instruments more comparable with geodetic ones. The main goal of this research was to evaluate the noise of low-cost GNSS receivers, to compare the positioning quality from different types of low-cost antennas, and to analyze the positioning differences between low-cost and geodetic instruments. The results from a zero baseline test indicated that the u-blox multi-frequency receiver, namely, ZED-F9P, had low noise that was at the sub-millimeter level. To analyze the impact of the antennas in the obtained coordinates, a short baseline test was applied. Both tested uncalibrated antennas (Tallysman TW3882 and Survey) demonstrated satisfactory positioning performance. The Tallysman antenna was more accurate in the horizontal position determination, and the difference from the true value was only 0.1 mm; while, for the Survey antenna, the difference was 1.0 mm. For the ellipsoid height, the differences were 0.3 and 0.6 mm for the Survey and Tallysman antennas, respectively. The comparison of low-cost receivers with calibrated low-cost antennas (Survey Calibrated) and geodetic instruments proved better performance for the latter. The geodetic GNSS instruments were more accurate than the low-cost instruments, and the precision of the estimated coordinates from the geodetic network was also greater. Low-cost GNSS instruments were not at the same level as the geodetic ones; however, considering their cost, they demonstrated excellent performance that is sufficiently appropriate for various geodetic applications.

Wideband and High-Gain D-Band Antennas for Next-Generation Short-Distance Wireless Communication Chips

This article presents two kinds of low-cost antennas for D-band short-distance wireless communication applications. Both the antennas are excited by a substrate integrated waveguide (SIW) feed line based on the printed circuit board (PCB) process. The first type is a stainless-steel-based horn antenna, fabricated by electric-discharging machining (EDM) process and selective laser melting (SLM) 3-D printing, respectively, for reducing cost. To integrate the horn antennas with the SIW feed line, a wideband transition structure from SIW to the rectangular waveguide is designed by suppressing higher order eigenmodes. The experimental data show that the integrated horn antenna can achieve 18.9% (129.5-156.5 GHz) -10 dB impedance bandwidth and a peak gain of 15.46 dBi. The second type of antenna is a single-layer rectangular patch antenna fed by SIW. By locally widening the SIW feed line to generate an equivalent shunt capacitance instead of using complex resonators, a wide impedance bandwidth can be realized. The measured -10 dB impedance bandwidth and the peak gain of the patch antenna are 20.8% (125.3-154.4 GHz) and 7.26 dBi, respectively. The two proposed antennas can provide comparable performance for different application requirements under the premise of a low fabrication cost.

Design of low-cost microstrip patch antennas with robust optimization

ABSTRACT This paper presents a robust optimization method to design patch antennas that consider uncertainties from the substrate electromagnetic properties and the manufacturing equipment. The robust optimization method is proposed to design an antenna that uses FR-4 as a substrate, addressing the uncertainties originated from the lack of standardization of this material properties and errors in the manufacturing process of the antenna. By addressing these uncertainties, robust design can result in a low-cost antenna with good performance that is less sensitive to deviations in the defined project variables. The optimization scheme used in this paper is based on NSGA-II, and the robustness of its solutions is quantified with the standard deviation of samples from the performance parameters in the uncertainty set from the design parameters. Two prototypes of patch antennas, one with linear and the other with circular polarization are designed, built, and measured.

A Dual-Band Printed Dipole Antenna for Unidirectional Radiation

This paper presents a dual-band printed dipole antenna for unidirectional radiation. The antenna is designed for the Wireless Local Area Network (WLAN) system that operating on both the frequency ranges of 2.400 – 2.483 GHz and 5.15 – 5.85 GHz. Radiated elements of the antenna are flat conductors on the surface of FR4 printed circuit board. All elements are on the same side of FR4. Coaxial line is chosen for feeding. It makes the antenna good matching and easy to assembly. The antenna is simulated by computer program before fabricating a prototype. It provides omni-directional radiation but has a direction with the gain about 5 dBi at the central of both operating frequencies. It is appropriate for the system that desired the signal to radiate surround but has some direction together. The size of the antenna is 44.0 × 60.0 mm2. Advantages of the antenna are low profile structure, light weight, and can be fabricated with cheap material. So, it is a low-cost antenna.

A Method to Develop Flexible Robust Optically Transparent Unidirectional Antennas Utilizing Pure Water, PDMS, and Transparent Conductive Mesh

A method to realize low-cost, optically transparent, flexible, and unidirectional antennas is presented in this article. The key to the method is making a flexible transparent reflector made using a new method—injection of pure water into a flexible transparent cavity that is made out of polydimethylsiloxane (PDMS) polymer and integrating the flexible reflector with a flexible dipole made of transparent conducting mesh. This method is simple and inexpensive. Hence, it is useful for large-scale production of transparent, flexible, robust, and low-cost antennas as well as RF/microwave components for wearable body-area networks and other such systems that require flexible and transparent components. To validate the method, an antenna operating in the 2.45 GHz band was designed, fabricated, and tested under various conditions. Its measured gain is 3.2 dBi and efficiency is 51%. To the best of our knowledge, this is the first water-based transparent flexible antenna. Due to the shielding effect of the water-based reflector, it produces a low specific absorption rate (SAR) in the human body when it is worn, as expected from a unidirectional antenna. Furthermore, it is investigated and confirmed that the use of pure water in the reflector makes the antenna significantly more efficient as opposed to salt water.