Corporate Feed Network Research Articles

High-Efficiency Broadband Planar Array Antenna with Suspended Microstrip Slab for X-Band SAR Onboard Small Satellites

In this paper, a high efficiency broadband planar array antenna is developed at X-band for synthetic aperture radar (SAR) on small satellites. The antenna is based on a multi-layer element structure consisting of two dielectric substrates made of Taconic TLY-5 and three copper layers (i.e., the parasitic patch (top layer), the active patch (middle layer), and the ground plane (bottom layer)). The parasitic patch resides on the bottom surface of the upper TLY-5 substrate while the active patch is printed on the top surface of the lower substrate. A Rohacell foam material is sandwiched between the top layer and the middle layer to separate the two dielectric substrates in order to achieve high directivity, wideband, and to keep the antenna weight to a minimum as required by the SAR satellite application. To satisfy the required size of the antenna panel for the small SAR satellite, an asymmetric corporate feeding network (CFN) is designed to feed a 12 × 16 planar array antenna. However, it was determined that the first corporate feed junction at the center of the CFN, where higher amplitudes of the input signal are located, contributes significantly to the leaky wave emission, which degrades the radiation efficiency and increases the sidelobe level. Thus, a suspended microstrip slab, which is simply a wide and long microstrip line, is designed and positioned on the top layer directly above that feed junction to prevent the leaky waves from radiating. The experimental results of the antenna show good agreement with the simulated ones, achieving an impedance bandwidth of 12.4% from 9.01 to 10.20 GHz and a high gain above 28 dBi. The antenna efficiency estimated from the gain and directivity eclipses 51.34%.

A high gain 16 × 16 Ka-band circularly polarized planar array antenna

In this article, a wide band circularly polarized microstrip array antenna with a gain of 26.5 dBiC at 29 GHz is developed and presented. The antenna structure contains six layers including the feeding and radiating layer. Modelling and experimental validations are performed on a 256 elements (16-by-16) antenna array. The proposed antenna comprises of corner truncated square patches that are fed at one feed point using the bottom layer corporate-feed network. The array exhibits S11<-10 dB over the frequency range 25–32.6 GHz (26.4%), axial ratio (AR) < 3 dB over 26.9–32 (17.3%) GHz and < 6° Half-Power Beamwidth (HPBW). The array antenna is fabricated through a multi-layer PCB process and has a size of 120 × 150 × 0.863 mm3. The measured results prove that the proposed antenna is a promising candidate for popular Ka-band applications like 5G and satellite communications.

Design of highly‐directive Night‐flowering Jasmine‐shaped printed radiator based array for Ku‐band applications†

SummaryThis article presents a four‐elements linear array of highly directive radiators for Ku‐band satellite applications. The antenna array's sole element is a newly introduced nature‐inspired Night‐flowering Jasmine‐shaped radiator. The proposed single element gives an appreciably decent gain and shallow cross‐polarization (x‐pol.) level along its main beam direction. The array's corporate feed network is designed in a precise manner to achieve a low level of loss and better bandwidth response. The fabricated sole antenna resonates at 17.95 GHz and offers a peak‐gain and return‐loss bandwidth of 11.54 dBi and 537 MHz, respectively. Similarly, 16.69 dBi absolute gain and 756‐MHz bandwidth have been achieved from the array geometry at 17.96 GHz resonating frequency. The prototypes' electromagnetic compatibility (EMC) is validated by their computed correction factor (CF) values, and those are becoming 43.73 and 38.57 dB/m, respectively. The measured cross‐pol. of both prototypes, along the entire HPBW region, is below −35 dB. The prototypes offer a reasonably good radiation efficiency of 92.09% and 97.25%, respectively. Both the prototype's measured results make an excellent agreement with the simulated outcomes.

Design of A Ka-Band 3D-Printed Dual-Polarization Magnetoelectric Dipole Antenna Array with Low Sidelobe

A Ka-band dual-polarization magnetoelectric (ME) dipole antenna array based on three-dimensional (3D)-printed technology with low sidelobe level (SLL) is proposed in this paper. The metal posts and cross-slots are explored to build a novel subarray with 2 × 2-unit ME-dipoles as the basic element. Creatively, a square waveguide to cross-slots transition with a pyramid horn cavity structure is investigated to feed the ME-dipole subarray. Furthermore, two types of power-tapering corporate-feed networks with laminated structures are used to design an 8 × 8-unit low-SLL array. The fabricated array has a relative bandwidth (VSWR &lt; 2) of 14.3% and 17.1%, with a realized gain higher than 25.8 dBi and 26.1 dBi for the H-pol. and V-pol., respectively. The maximum radiation efficiency for both arrays is 73.2%. The measured first sidelobe levels are less than –17.5 dB for both polarizations. With competitive performance and low fabrication cost, the proposed dual-polarization ME-dipole antenna array would be valuable for polarization-agile radar and communication systems.

Wearable Metasurface Antenna based on Electrically‐small Ring Resonators for WBAN Applications

This letter proposes a novel wearable metasurface antenna (MSA) based on electric ring resonators (ERR) for 5.8 GHz wireless body area network (WBAN) applications. All substrates of the proposed design are made from the semi-flexible Rogers RT5880 material. To achieve size miniaturization, 6 × 8 ERR elements are placed on a flat surface connected through a corporate-feed network. The total dimensions of the proposed MSA are 120 × 90 × 1.574 mm3 (2.2λ0 × 1.69λ0 × 0.029λ0). Furthermore, an average efficiency of 79.9%, and a peak gain of 12.82 dBi with a stable radiation pattern have been realized in the operating band. The performance of the proposed MSA is analyzed in close proximity to the human body tissue. The experimental results show good agreement with the numerical data. With all these features, the proposed design is a good candidate for wearable WBAN applications.

Performance Analysis of Microstrip Antenna with Several Feed Networks for Satellite Communication

The modern wireless communication systems demand significantly higher bandwidth with a highly directive antenna for better performance. For this purpose, the feed networks such as Series Feed (SF), Corporate Feed (CF), and Corporate-Series Feed Network (CSFN) in the design of antennas play a vital role. Therefore, in this paper, rectangular microstrip antennas with inner ring slot, two semi-circular slots on both sides of the microstrip, and two director elements have been designed. The proposed antennas in four sets with different shapes for satellite communication operate at the Ku-band frequency. In this design, copper (annealed) has been used as material for the ground plane. The substrate material of this proposed antenna is Rogers RT5880, with a dielectric constant at 2.2. Moreover, the probe feed technique has been used in this antenna, further followed by SF, CF, and CSFN networks. The presented design is simple, compact, and very economical with optimal gain and bandwidth. The structure parameters of this proposed antenna are numerically computed. The antenna features are simulated by CST Microwave Studio, a commercial simulator based on finite integration techniques that support the numerical analysis. Further, the antenna performances based on the considered feeding techniques of the proposed antenna have been compared.

On the Use of Ridge Gap Waveguide Technology for the Design of Transverse Stub Resonant Antenna Arrays.

This paper presents some considerations on the design of a novel antenna consisting of the combination of a transverse stubs (TS) array excited by Ridge Gap Waveguides (RGWs), as well as a discussion of the experimental results obtained from a prototype that was manufactured and measured. A combination of Continuous Transverse Stubs (CTSs) is used as the starting point. Subsequently, the CTSs are modified to include some metallic blockers that split each CTS into a combination (array) of shorter TSs. This is performed in order to excite each individual TS column using a different RGW; thus, ensuring a close to uniform field distribution in the transverse plane of the TS arrays. Hence, the directivity of the antenna is increased. As a series-feed configuration is considered, the antenna keeps a resonant behaviour, having a narrow-band response. A Corporate Feeding Network (CFN) using the aforementioned RGW technology placed in the same layer as the rest of the antenna is included in the design. The radiating area of the antenna is, finally, with a simulated peak gain of 26.2 dBi and a Side Lobe Level (SLL) below −13 dB. A prototype is manufactured and tested. The simulated and measured radiation patterns maintain similar shapes to those of the simulations, with very similar angular widths in both main planes, although the frequency corresponding to the highest directivity changes to 31.8 GHz. A matching bandwidth of 517 MHz and a gain of 24.5 is, finally, achieved at that frequency.

A Wide-Band High-Efficiency Hybrid-Feed Antenna Array for mm-Wave Wireless Systems

A wide-band and high-efficiency planar antenna array with a novel hybrid-feed structure is proposed in this article. By combing the coaxial-line feed magneto-electric (ME) dipoles with the aperture coupled dielectric cavity, a hybrid-feed 2 × 2-unit ME-dipole sub-array is invented. The low-loss ridge gap waveguide (RGWG) corporate-feed network is used to replace the high-loss substrate-based feed networks and high-cost RWG feed networks. New forms of RGWG H-plane divider are designed to build the RGWG feed network. An 8 × 8-unit ME-dipole antenna array is designed and fabricated to verify the validity of the array. The radiation part consists of two layers of a low-cost printed circuit board (PCB), and the feeding part consists of two copper plates manufactured by computer numerical control (CNC) milling. Measured results show that a relative bandwidth of 16.4% with |S11| &lt; −10 dB is achieved, with a maximum radiation efficiency of 85%. The stable symmetric radiation patterns are observed in both the E-plane and H-plane, covering the operation band. Based on the measured results, a 16 × 16-unit ME-dipole antenna array is simulated. Results indicate that the proposed array has wide-band and high-efficiency features, which is suitable for large-scale array design in mm-wave wireless systems.

2x2 Grid Array Design with E-shaped Microstrip Elements

The paper proposes a work of four element in a 2×2 grid fashioned with E-shaped microstrip patch antenna with corporate fed .The paper compares the proposed design with four elements with a single element and a 2 element array design.All the three antenna designs use E shaped microstrip patch as an element. The design of the grid is achieved through the design of a single element, the design of a 1×2 array and finally the design of the 2×2 grid on an FR4 epoxy substrate of thickness 1.5 mm. A corporate feed network of microstrip lines is used to excite the array. The performance of each stage is studied in terms of the return loss parameter, the far field gain, and the beam-widths are observed in each case from simulation results. The resonant frequency in each case is 3.8 GHz. Through comparision of simulation results the paper shows that as the number of elements is increased, the beam-width reduces. In other words, the directivity is increased. Further, it is also observed that the gain and bandwidth is the minimum for the single patch, followed by that of the 1×2 array and the maximum for the 2×2 grid. Thus,it is ssen that the proposed four element antenna with corporate feeding performs better as compared to antennas with either only single patch element or two element array. The construction of the grid leads to increase in gain, bandwidth and directivity of the antenna.

Millimeter-Wave High-Gain Magneto-Electric Dipole Antenna Array With Pillbox Corporate Feed Network

This article presents a high-gain antenna array with the use of magnetoelectric (ME) dipole antenna elements operating at millimeter-wave frequencies. The proposed array achieves wide bandwidth, high gain, and low sidelobe level (SLL) in its planar structure. A highly efficient power divider consisting of pillbox transition and corporate feed network is introduced to produce equal phase but nonuniform power distributions to all array elements such that it can be for suppressing the SLL of the array. The radiating element is constituted by a cavity-backed slot-coupled ME dipole, which offers a wide impedance bandwidth and a stable radiation pattern. A prototype of the antenna array is fabricated and measured to verify the proposed design. The array achieves an impedance bandwidth of 20.8% (for the reflection coefficient ≤ -10 dB), covering the frequency range from 54.2 to 66.8 GHz. The average gain of the array is 28.5 dBi in its operating bandwidth, with a peak gain of 29.6 dBi at 65 GHz. The lowest E-plane SLL level over the entire bandwidth is -18 dB. This proposed antenna array has potential applications in long-distance millimeter-wave communications due to its merits of wideband, high gain, and low SLL features.

Designing of a 2x2 E-shaped Microstrip Patch Grid Antenna

In this work, a 2×2 grid of E-shaped patch antennas is proposed. The design of the grid is achieved through the design of a single element, the design of a 1×2 array and finally the design of the 2×2 grid on an FR4 epoxy substrate of thickness 1.5 mm. A corporate feed network of microstrip lines is used to excite the array. The performance of each stage is studied in terms of the return loss parameter, the far field gain, and the beam-widths are observed in each case from simulation results. The resonant frequency in each case is 3.8 GHz. It is observed that as the number of elements is increased, the beam-width reduces. In other words, the directivity is increased. Further, it is also observed that the gain and bandwidth is the minimum for the single patch, followed by that of the 1×2 array and the maximum for the 2×2 grid. Thus, the construction of the grid leads to increase in gain, bandwidth and directivity of the antenna.

Broadband and efficient patch array antenna fed by substrate integrated waveguide feed network for Ku‐band satellite applications

A new class of multi-layer microstrip patch antenna (MPA) array fed by substrate integrated waveguide (SIW) cavities is presented for Ku-band applications. An efficient compact multi-layer SIW feeding network is designed, which has lower losses than the conventional corporate feeding network based on microstrip lines or coplanar waveguides. A 4 × 4 array consists of four stacked layers, including three based on the SIW technology as a feeding network and one layer for the radiating antenna array. Each layer can easily be fabricated from a dielectric substrate and processed using the printed circuit board (PCB) technology. Afterward, all the PCB laminates are stacked together and tied by screws. The measured antenna operates from 11.2 to 13.6 GHz achieving 19.35% bandwidth. The measured peak gain at 12.5 GHz is 17.1 dBi, equivalent to 71.47% aperture efficiency. The fabricated array exhibits several advantages: broadband, low cost, compactness, high radiation efficiency, high aperture efficiency, and lightweight, which makes it a candidate for Ku-band satellite applications.

LTCC-Integrated Dielectric Resonant Antenna Array for 5G Applications.

A millimeter-wave dielectric resonator antenna array with an integrated feeding network and a novel alignment superstrate in Low Temperature Cofired Ceramics (LTCC) technology is presented. The antenna array consists of 16 cylindrical DR antenna (CDRA) elements operating at 28 GHz for mm-Wave 5G applications. The array is fed by an inverted microstrip corporate feeding network designed and built in the same LTCC stack as the resonators. A grooved and grounded superstrate is introduced to facilitate the alignment of the individual array elements while enhancing the overall performance of the antenna array. The performance of the proposed stack is evaluated numerically and compared with measured data. Measured results show an impedance bandwidth of 9.81% at 28.72 GHz with a maximum realized gain of 15.68 dBi and an efficiency of 88%, and are in excellent agreement with simulations.

Ka-band planar slotted waveguide array based on groove gap waveguide technology with a glide-symmetric holey metasurface

The design of a planar slot array in groove gap waveguide technology implemented by glide-symmetric holes as Electromagnetic Band Gap structure is here presented. Despite the advantages of using holes instead of pins in terms of manufacturing simplicity and cost,the larger size of the holes compared to pins needs to be considered when designing slot arrays without grating lobes. A 1 to 4 corporate feed network is designed using this technology as well. Corrugations are included to further reduce the grating lobes. Experimental results support the viability of the proposed concept for designing glide-symmetric planar arrays of any size.

Triangular Slot-Loaded Wideband Planar Rectangular Antenna Array for Millimeter-Wave 5G Applications

This paper presents a design of a triangular slot-loaded planar rectangular antenna array for wideband millimeter-wave (mm-wave) 5G communication systems. The proposed array realizes an overall size of 35.5 × 14.85 mm2. To excite the array elements, a four-way broadband corporate feeding network was designed and analyzed. The proposed array offered a measured impedance bandwidth in two different frequency ranges, i.e., from 23 to 24.6 GHz and from 26 to 45 GHz. The single-antenna element of the array consists of a rectangular patch radiator with a triangular slot. The partial ground plane was used at the bottom side of the substrate to obtain a wide impedance bandwidth. The peak gain in the proposed array is ≈12 dBi with a radiation efficiency of &gt;90%. Furthermore, the array gives a half-power beamwidth (HPBW) of as low as 12.5°. The proposed array has been fabricated and measured, and it has been observed that the measured results are in agreement with the simulated data.

Wireless communication applications of the variable inclination continuous transverse stub array for Ku‐band applications

A wideband and continuous beam steering variable inclination continuous transverse stub antenna array is presented in the communication. The proposed antenna consists of a continuous transverse stub (CTS) array and a line source generator (LSG). These two parts are designed and optimized separately. The LSG structure is generated by a Pillbox transition. The CTS array is composed of 20 radiating slots and is fed by a corporate-feed network. The corporate-feed network adopts a series-parallel hybrid structure to realize lower profile and high-efficiency performance. The relative rotation movement between the CTS array and the LSG generates a phase gradient on the radiation part such that the proposed antenna can obtain a continuous beam in the upper hemisphere. Based on the array synthesis encryption sampling technology theory, the relationship between the mechanical rotation angle and the beam direction is analysed and obtained. To validate the antenna concept, the antenna is fabricated and measured. The simulation and measurement results are in good agreement. Through the rotation of the CTS array, the designed antenna achieves a ±56°scan. The measured results show that the array can achieve an impedance bandwidth of 16% in Ku-band at the centre frequency of 12 GHz with 67% aperture efficiency. The proposed antenna has the characteristics of low profile, high efficiency, large coverage, and wideband, which is well suited for mobile satellite communication.

A Novel Dual-Polarized Continuous Transverse Stub Antenna Based on Corrugated Waveguides—Part I: Principle of Operation and Design

Continuous transverse stub (CTS) arrays represent a high-performance and affordable solution for fixed-beam and scanning flat antenna systems, though intrinsically linearly polarized. In these systems, the polarization is controlled using add-on polarization converters or combining cross-connected CTS arrays. This two-part article presents a novel parallel-fed CTS antenna which achieves dual-linear polarization using, instead, a single array and two orthogonally polarized excitation fields. In this article, it is shown that, due to modal coupling, standard parallel-plate waveguides (PPWs) are not suitable as building blocks of the proposed antenna. Therefore, an alternative waveguide, the corrugated PPW (CPPW) is introduced. The dispersion characteristics of such CPPW are investigated. Guidelines to independently design the dispersion properties of the two propagating modes and avoid the excitation of higher order modes are provided. Based on this study, the design and simulated performance of a Ka-band array of eight long slots parallel-fed by a dual-mode CPPW corporate-feed network are described. An extensive experimental validation of the concept is presented in Part II.

Study and Analysis of Rectangular Microstrip Patch Antenna at 28GHz for 5G Applications

—Fifth generation (5G) is the next major phase of mobile telecommunications standards beyond the current 4G, which will operate at millimeter-wave frequency band. In any wireless device, the performance of radio communications depends on the design of an efficient antenna. This paper presents designs for rectangular microstrip antennas (single element, two elements, four elements and eight elements at 28 GHz), where 28GHz is one of the standard frequencies of the 5G communications. For better impedance matching, corporate feeding network is used in array configuration. Microstrip line and patch are etched on RT Duroid 5880 (dielectric constant of 2.2 and a height of 0.5 mm) substrate material. Array antenna improves various performance parameters, namely, return loss characteristics, impedance bandwidth, gain, directivity, and radiation pattern. It is observed an improvement in most parameters. From the simulation results of eight elements array configuration, it is increased of 95.15% gain and directivity as compared to a single element configuration. It is also noticed that there is an increase of 148.54% in impedance bandwidth as compared to a single element configuration. There is decreased of beamwidth in 52.06 % as compared to a single element. Thus, proposed eight elements microstrip patch array with modified corporate feeding is effective candidate for future 5G applications.

E-Band Full Corporate-Feed 32 × 32 Slot Array Antenna With Simplified Assembly

This letter presents a high-gain 32 × 32-element full corporate-feed array antenna using a simplified assembly of only two split blocks. This is made possible by a new feeding configuration which eliminates the cavity-backed layer used in conventional designs. E-plane T-junctions, as well as the single-ridge waveguide output structure, are used in the full corporate-feed network to reduce its size. This helps to realize the one-to-one corresponding excitation between the output port of the feed network and the radiation slots. In addition, a transition structure from single-ridge waveguide to double-ridge waveguide is employed to improve the impedance matching bandwidth of the radiation part. For demonstration, a prototype is designed, fabricated, and measured. Experimental results show that the array antenna achieves an impedance bandwidth of 19% (71-86 GHz) with input reflection coefficient better than -13 dB, the antenna efficiency of over 76.4%, and peak gain of better than 38.4 dBi over the entire operating band.

Dual-Band Single-Layer Slot Array Antenna Fed by K/Ka-Band Dual-Mode Resonators in Gap Waveguide Technology

This letter presents a 4 × 4 single-layer dual-band array antenna operating in the K- and Ka-band using gap waveguide (GW) technology. Radiating elements consist of I-shaped slots located on the top plate of the antenna and backed by a novel coaxial cavity with the dual-frequency operation. The antenna presents two ports, one for each band, and radiates a directive far field pattern with linear polarization. A single-layer wideband corporate-feed network is used to excite the cavities. In addition, a diplexer is integrated as part of the network to separate both working bands. Experimental results show impedance and radiation pattern bandwidths larger than 2 GHz in both bands.