Substrate Integrated Waveguide Antenna Research Articles

A Compact, Wideband, Two-Port Substrate-Integrated Waveguide Antenna With a Central, Double-Slotted, Metallic Plate Flanked by Two Paired of Corrugations for Radar Applications

This communication proposes a compact, wideband, two-port substrate-integrated waveguide (SIW) antenna with a central, double-slotted metallic plate flanked by two paired corrugations for radar applications. The proposed antenna uses a two-layer structure, with a slotted metallic plate with corrugations on the top layer and an FR-4 substrate SIW on the bottom layer. The antenna has compact dimensions of 63 mm $\times$ 54 mm ( $2.32\lambda _{0} {\times}\,\, 1.99\lambda _{0}$ ) with a low profile of 7 mm ( $0.26\lambda _{0}$ ). To understand the operating principle of the two-port SIW antenna clearly, modal analysis is performed for single-port SIW antenna. The antenna satisfies a −10 dB reflection coefficient from 10.15 to 11.58 GHz. Although the separation between the two central slots is minimized to 4 mm ( $0.14\lambda _{0}$ ), the isolation performance remains excellent (less than −30 dB). The gain enhancement, with a narrow beam pattern for radar applications, is realized using constructive superposition of in-phase electromagnetic energy from the two slots. In addition, because the antenna has two ports, it also has a beam scanning function from −12° to +12° in its boresight direction. The experimental and simulated results from the proposed antenna are in good agreement.

Design of reconfigurable integrated substrate integrated waveguide (SIW) filter and antenna using multilayer approach

This article presents an integrated technique for reconfigurable substrate integrated waveguide (SIW) and reconfigurable patch antenna by using the varactor diodes. A reconfigurable SIW filter and reconfigurable patch antenna were integrated using the multilayer technique into a single structure in order to realize the integration technique. Design and validation of an equivalent circuit with the varactor diode is presented to study the tunable mechanism. A good performance between the simulated and measured results was achieved. This proposed structure of the reconfigurable integrated SIW filter and antenna is useful for wireless communication systems especially in telecommunication technology.

Compact One-Sixth Mode Substrate Integrated Waveguide Based Antennas for Wireless Communication and Public Safety Systems

The authors have chosen a hexagonal SIW cavity and designed it to resonate at the fundamental TM01 mode at 5.9 GHz. The cavity is then bisected along its diagonal to produce a semi-hexagonal half-mode substrate integrated waveguide antenna, having a center frequency of 5.57 GHz lying within IEEE 802.11a WLAN U-NII 2C band. The half-mode SIW antenna depicts a gain of 5.5 dBi. A furthermore division of the full mode parent hexagonal resonator into six equal parts, each an equilateral triangle, constitutes the one-sixth mode of the parent cavity. This one-sixth mode SIW antenna operates at the resonating frequency of 5.4 GHz unlicensed band producing a gain of 5.38 dBi and finds suitable application in wireless communication systems. The antenna is further miniaturized with the inclusion of double T-shaped slot. This miniaturized antenna resonating at 4.96 GHz with a gain of 4.99 dBi is very apt in its use for public safety systems in the IEEE 802.11j 4.9 GHz band. Each of the structures is studied parametrically in great detail and the antenna prototypes are fabricated on Arlon AD270 substrate. HFSS software is used to simulate and analyze all of the antenna parameters. The simulated and measured results tallied against are found to be in good agreement with each other.

Dual-Band and Polarization-Flexible CRLH Substrate-Integrated Waveguide Resonant Antenna

A dual-band and polarization-flexible substrate-integrated waveguide (SIW) resonant antenna based on composite right-/left-handed (CRLH) structure is presented in this letter. The proposed antenna consists of a CRLH SIW resonator and dual feeding lines. A slot and surface-mount technology capacitors on the top metallic layer of SIW resonator provide necessary reactance to realize multiresonance CRLH structure. Due to the intrinsic multiband characteristic of a CRLH structure, the proposed antenna can provide dual-band broadside radiations. Polarization flexibility is realized by two orthogonal feedlines. Utilizing the CRLH resonator instead of the conventional square resonator, such as patch antenna, allows antenna miniaturization. The electrical lengths of the sidewalls for the proposed square SIW resonant antenna are 75% (for first resonant mode) and 44% (for second resonant mode) shorter than that of the previously proposed dual-band polarization-flexible SIW antenna. To highlight the unique advantages, the dual-band circularly polarized antenna array based on the proposed antenna element is presented. Dual-band circularly polarized radiation is supported by the dual-band CRLH transmission-line-based feeding network.

A Single-Layer Dual-Frequency Shared-Aperture SIW Slot Antenna Array With a Small Frequency Ratio

This study provides a solution to achieve a single-layer dual-frequency shared-aperture slot antenna array with a small frequency ratio (FR) based on a substrate integrated waveguide (SIW) technology. Cavity resonator principles are applied to a distinctive SIW antenna array cavity to obtain dual operational frequencies on two separate ports while sharing the same radiation aperture. A 24-element SIW array prototype is designed and fabricated to validate the solution. The prototype has dual frequencies and a shared aperture with a small FR of 1.03 while maintaining a single-layer planar configuration and low cost. The two ports operate at 5.701 and 5.888 GHz. Reasonable parameters are obtained from the simulation and measurements, and there is a good agreement between the results.

A Simple Technique for Open-Stopband Suppression in Periodic Leaky-Wave Antennas Using Two Nonidentical Elements Per Unit Cell

A simple technique is presented for the complete suppression of the open stopband in periodic leaky-wave antennas using two similar but nonidentical elements per unit cell. With the technique, one needs only to optimize the distance between the two elements and the dimension of the second element, starting with a quarter of the period and the dimension of the first element. With the simple design procedure, the technique is practical and effective for the open-stopband suppression for various periodic leaky-wave antennas. Two periodic leaky-wave antennas with the technique are demonstrated. The first one is a new developed substrate-integrated waveguide antenna with two nonidentical transverse slots per unit cell. The antenna has a wide scanning range from the backward endfire to the forward direction and does not suffer from blind scanning points at endfires (if it is placed on an infinite ground plane). The antenna is theoretically investigated. The simulation and measured results are consistent with the theoretical results. The second one is a microstrip combline leaky-wave antenna, in which each unit cell contains two nonidentical open-ended stubs. The two examples validate that the technique proposed in this paper can completely eliminate the open stopband in periodic leaky-wave antennas.

Closely spaced MIMO antenna based on substrate‐integrated waveguide technology

AbstractIn this letter, a compact array system for multiple‐input‐multiple‐output (MIMO) applications is designed, based on substrate integrated waveguide (SIW) technology. In order to verify the potential of the proposed antenna as a MIMO application, 2 types of 4‐element SIW antenna are placed in a compact space. Four isosceles triangle (type 1) and rectangle (type 2) SIW antennas, consisting of metallic vias at 1 side and slit at the other side, are used as radiating elements. The side‐to‐side distance of the elements is only 0.006 λ0. The peak gain of these patterns is −3 dBi. The envelope correlation coefficient is calculated from the measured 3D patterns and shows good MIMO performance. The proposed antenna achieves both a significant reduction of size and mutual coupling by metallic vias.

A compact planar circularly polarized eighth-mode substrate integrated waveguide antenna

AbstractA compact and planar broadband circularly polarized (CP) eighth-mode substrate integrated waveguide (EMSIW) antenna is proposed in this paper. An isosceles right triangular waveguide with one electric sidewall (located on one of its catheti) and two magnetic sidewalls (located on the other two edges of the triangle) is presented to investigate the characteristics of the EMSIW. The closed-form mode solutions of the electromagnetic field components and the cut-off frequencies are derived for all propagating modes in this triangular waveguide. The simulated electromagnetic field distribution is consistent with the analytical results. The resonant frequencies of the EMSIW cavity are then determined. A CP antenna consisting of four EMSIW elements is designed, fabricated, and measured. The measured 3-dB axial ratio bandwidth of the antenna is 21.6% from 4.72 to 5.86 GHz. Within this frequency range, the measured reflection coefficient is below −10 dB, and the measured peak gain in circular polarization at broadside is 6.89 dBic at 5.1 GHz.

Increasing the bandwidth of cavity-backed SIW antennas by using stacked cavities

AbstractThis paper presents a technique to increase the bandwidth in substrate integrated waveguide (SIW) cavity-backed antennas, inspired by the design of cavity filters. The proposed structure consists of a slot antenna backed by two cavities, located one on top of the other and coupled through a slot. To demonstrate the bandwidth increase, a standard cavity-backed SIW antenna, with a rectangular slot etched in the top metal plane, has been designed, manufactured, and measured. Subsequently, a similar antenna was developed, by doubling the substrate thickness with the aim to improve the bandwidth. Finally, the new topology of two-cavity SIW antenna has been implemented and compared with the two previous ones. Simulation and experimental results show that the proposed two-cavity antenna exhibits a bandwidth twice as large as the standard SIW cavity-backed antenna.

High-gain narrow-band slotted antenna based on ENZ SIW structure

The development of a slotted substrate integrated waveguide antenna with an epsilon near zero (ENZ) material is presented. Here, an ENZ waveguide structure is used in the design. The ENZ material is used to realize unconventional tunneling of electromagnetic energy with ultra-thin subwavelength channels and it is considered to attain a highly directive narrow band antenna. The effect of the various parameters of the antenna is studied by simulation. A prototype is fabricated and the measurement results are compared with the simulated values.

A Novel Manufacturing Process for Compact, Low-Weight and Flexible Ultra-Wideband Cavity Backed Textile Antennas.

A novel manufacturing procedure for the fabrication of ultra-wideband cavity-backed substrate integrated waveguide antennas on textile substrates is proposed. The antenna cavity is constructed using a single laser-cut electrotextile patch, which is folded around the substrate. Electrotextile slabs protruding from the laser-cut patch are then vertically folded and glued to form the antenna cavity instead of rigid metal tubelets to implement the vertical cavity walls. This approach drastically improves mechanical flexibility, decreases the antenna weight to slightly more than 1 g and significantly reduces alignment errors. As a proof of concept, a cavity-backed substrate integrated waveguide antenna is designed and realized for ultra-wideband operation in the [5.15–5.85] GHz band. Antenna performance is validated in free space as well as in two on body measurement scenarios. Furthermore, the antenna’s figures of merit are characterized when the prototype is bent at different curvature radii, as commonly encountered during deployment on the human body. Also the effect of humidity content on antenna performance is studied. In all scenarios, the realized antenna covers the entire operating frequency band, meanwhile retaining a stable radiation pattern with a broadside gain above 5 dBi, and a radiation efficiency of at least 70%.

Coupled Eighth-Mode Substrate Integrated Waveguide Antenna: Small and Wideband With High-Body Antenna Isolation

A novel antenna design for wideband operation is presented, consisting of a system of two coupled miniaturized eighth-mode resonant radiating cavities with a low-complexity feeding network. The design methodology relies on the virtual magnetic boundaries along the symmetry planes of a rectangular waveguide resonator, for size reduction, and the frequency bifurcation of two tightly coupled resonators, for bandwidth enhancement. After discussing its operating principle, a prototype targeting wearable applications is designed, manufactured, and validated. Multiband operation is achieved with simultaneous coverage of the 2.4-GHz ISM band and the LTE-7 up- and downlink-bands. Measurements in free-space and on-body scenarios validate the antenna’s performance. A bandwidth of 414 MHz (16.2%) is measured, as well as a maximal gain of 4.7 dBi. The directive patch-like radiation pattern and the ground plane topology lead to high body-antenna isolation and good on-body performance. Impedance bandwidth and radiation pattern remain stable when the antenna is worn by a person and bent around a cylinder to mimic deformation.

Circularly‐polarised cavity‐backed wearable antenna in SIW technology

This study presents a circularly-polarised substrate-integrated waveguide (SIW) antenna implemented using a textile substrate and operating at 2.45 GHz, in the industrial, scientific, and medical frequency band. The antenna topology is based on a folded cavity with an annular ring as a radiating element, and it permits to obtain compact size and low sensitivity to the environment, without deteriorating the radiating performance. These characteristics, together with the choice of adopting a textile substrate, make the SIW antenna suitable for the integration in wearable systems for body-centric applications. The electromagnetic performance of the proposed antenna achieved in simulations was verified through the measurement of the device in an anechoic chamber. The circularly-polarised antenna exhibits a maximum gain of 6.5 dBi, a radiation efficiency of 73% and a very high front-to-back ratio.

Wideband excitation technology of substrate integrated waveguide TE 30 mode and its antenna application

An excitation technology of TE 30 mode in substrate integrated waveguide (SIW) and its application for designing a compact Yagi-Uda antenna array is proposed. Coplanar waveguide (CPW) structure is adopted as the input and two slots of CPW are further extended in the SIW along the third lines in the longitudinal direction to convert the electromagnetic field pattern between the slot and SIW. Therefore, TE 30 mode is successfully excited. A Yagi-Uda antenna array fed by the SIW operating at TE 30 mode is fabricated and measured. A broad impedance bandwidth of 46% (| S 11 | <; -10 dB) ranging from 7.8 to 12.4 GHz is achieved with obtaining a maximum gain of 8.5 dBi. Compared with the traditional SIW antenna array based on TE 10 mode, the higher mode excitation technology not only simplifies the feeding network but also reduces the difficulty of processing.

LTCC-Integrated $H$ -Plane Bends for THz Antenna-in-Package Solution

We present a compact terahertz antenna-in-package solution using a substrate integrated waveguide (SIW), which connects an integrated circuit (IC) to an SIW antenna. To suppress the leakage of electromagnetic waves due to bending a low-temperature cofired ceramic (LTCC) substrate, an H-plane bend SIW in the LTCC was investigated using the E-plane split-block technology. We introduced an IC with a CPW-to-waveguide transition into the hollow SIW. The insertion loss, estimated by measuring a back-to-back transition with the H-plane-bend SIW, is 1.6 dB at 300 GHz, and 49-GHz bandwidth with less than 10-dB return loss is achieved.

A novel circularly polarized cavity backed SIW antenna with capability to change polarization diversity by a reconfigurable polarizer structure

This article examines a substrate integrated waveguide (SIW) cavity-backed circularly polarized diversity antenna. In the proposed novel antenna, parasitic patch and reconfigurable diodes are used to change polarization diversity from left hand to right hand and vice versa, respectively. In addition to, what makes distinctive proposed antenna in compared with similar works, is ability to change linear polarization from a SIW slot to circularly polarization by a parasitic patch. Chopping off two diagonally opposite corners makes the resonance frequency of the mode along this diagonal to be higher than that for the mode along the unchopped diagonal. By exciting parasitic patch with a slot along axes of it the orthogonal modes are generated which causes to CP. The comparison between simulation and measurement results validate antenna design. The measured impedance BW (VSWR < 2) for state 1 and 2 are 22.18% (11.86-14.82 GHz) and 21.68% (11.88-14.77 GHz), and The measured 3-dB AR BW for states 1 and 2 are about 11.46% (11.43-12.82 GHz) and 11.23% (11.43-12.79 GHz), respectively. Finally, the measured maximum gain is 9.81 dBic.

One-dimensional leaky-wave antenna producing multiple beams

In this paper, far-field pattern of one-dimensional leaky-wave antenna (LWA) is directly synthesized by sinusoidally modulating surface currents of the antenna. Due to the characteristic of light cone in distinguishing surface waves and radiation waves, the numbers of the beams are selectable depending on the modulations. A one-dimensional substrate integrated waveguide (SIW) antenna producing two beams are designed and fabricated. Measurements agree very well with the simulations, indicating the validity of the presented synthesizing method as well as the practicalities of the presented SIW antenna.

Broadband Dual Circularly Polarized Substrate Integrated Waveguide Antenna

In this letter, a broadband dual circularly polarized substrate integrated waveguide (SIW) antenna is proposed. The proposed antenna consists of a quarter mode SIW cavity, two open-stubs and defected ground structures (DGSs). The antenna has two ports. One of them provides left-hand circular polarization and the other provides right-hand circular polarization. Circular polarization is obtained from TE202 mode of the quarter mode resonator. The cavity loaded with two perpendicular open-stubs at the corner provides dual mode resonance, which is then utilized to increase circular polarization bandwidth of the antenna. Furthermore, DGSs are used to improve isolation between the ports. The measured 3 dB axial ratio (AR) bandwidth of the antenna is approximately 11.2% at 12.5 GHz with a return loss more than 10 dB over the band.

Terahertz MMICs and Antenna-in-Package Technology at 300 GHz for KIOSK Download System

Toward the realization of ultra-fast wireless communications systems, the inherent broad bandwidth of the terahertz (THz) band is attracting attention, especially for short-range instant download applications. In this paper, we present our recent progress on InP-based THz MMICs and packaging techniques based on low-temperature co-fibered ceramic (LTCC) technology. The transmitter MMICs are based on 80-nm InP-based high electron mobility transistors (HEMTs). Using the transmitter packaged in an E-plane split-block waveguide and compact lens receiver packaged in LTCC multilayered substrates, we tested wireless data transmission up to 27 Gbps with the simple amplitude key shifting (ASK) modulation scheme. We also present several THz antenna-in-packaging solutions based on substrate integrated waveguide (SIW) technology. A vertical hollow (VH) SIW was applied to a compact medium-gain SIW antenna and low-loss interconnection integrated in LTCC multi-layer substrates. The size of the LTCC antennas with 15-dBi gain is less than 0.1 cm3. For feeding the antenna, we investigated an LTCC-integrated transition and polyimide transition to LTCC VH SIWs. These transitions exhibit around 1-dB estimated loss at 300 GHz and more than 35 GHz bandwidth with 10-dB return loss. The proposed package solutions make antennas and interconnections easy to integrate in a compact LTCC package with an MMIC chip for practical applications.

A novel circularly polarized half mode circular substrate integrated waveguide antenna using meandered strip feeding technique

A technique to design a compact half mode substrate integrated circular cavity (HMSICC) cavity backed antenna is presented in this letter. The proposed antenna achieves left-handed circularly polarized(LHCP) using a crossed slot, The feeding meandered stripline on the middle layer are able to achieve better impedance match and axial ratio bandwidth. Measured results show that the prototype achieves a bandwidth of 10.5% for −10dB return loss, axial ratio(AR) bandwidth is about 3% with maximum gain of 6.5dBi. © 2016 Wiley Periodicals, Inc. Int J RF and Microwave CAE 26:668–673, 2016.