Substrate Integrated Waveguide Technique Research Articles

Highly selective filtering power divider using substrate integrated waveguide technique for radar applications

<p><span>This article exhibits a filtering power divider designed with substrate integrated waveguide (SIW) technique, having the power dividing as well as filtering functionalities. In the design band-pass performance is realized by merging SIW structure having high-pass response and complementary split ring resonator (CSRRs) with parallel tank LC resonant response and the dumbbells shape defected ground structure (DGS) with high out of band rejection characteristics. The anticipated structure serves as both a power divider and a filter, it reduces both the cost and the size of the system. Structure is constructed and tested to confirm the design functionality. The measurement result shows the return loss of -25.94 dB with 3-dB fractional bandwidth of 2.85% at 14 GHz.</span></p>

Design and Analysis of Sierpinski Fractal Antennas for Millimeter‐Wave 5G and Ground‐Based Radio Navigation Applications

ABSTRACTThe paper describes compact fractal antennae combined with ground defected structures (DGS) and substrate integrated waveguide (SIW) techniques for enhancing resonate and multiband behavior concerning bandwidth, gain, and radiation in the desired mm‐wave region. Based on the proposed antennae, multiple good notches over wide bands depict a good radiation pattern. The antennae's ultra wide bandwidths (UWB) are 16, 16, and 11.4 GHz concerning resonant frequencies 26.34, 30.35, 34.5, 36.65 GHz; 25.8, 32.2, 35.3 GHz; 30.22, 37.68 GHz, of concerning antennae ant 1 (FA1), 4 (FA2), and 6 (FA3), respectively. The proposed antenna (FA3) with the SIW technique has a peak gain of 5.9 dBi and a peak front‐to‐back ratio of 20 dB, respectively. The proposed antennas are targeted to cover the practical contribution aspect, including advanced 5G bands support (24–40 GHz), broadband spectrum, frequency agility, low 3 dB beamwidth, interference reduction, and medical application suitability, respectively. The proposed antennae also cover the desired mm wave 5G region with different resonating notches over ultra‐wide bandwidth, such as n257, n258, n259, n260, and n261, and ground‐based radio navigation applications. Results are validated with vector network analyzer, spectrum analyzer, and power sensor in the presence of absorber, respectively.

The Riblet Short-Slot Coupler Using Substrate Integrated Waveguide (SIW) for High-frequency Applications

Substrate Integrated Waveguide (SIW) involves the conductive via holes immersed in a dielectric substrate that connects two substrate plates. This article presents a new SIW technique to enhance the operational bandwidth of the Riblet Short-Slot coupler. To demonstrate the proposed SIW technique, two Riblet Short-Slot couplers are designed and investigated at two different high-frequency ranges, Ku-band and K-band. The bandwidth of the proposed couplers is improved by introducing multiple layers of SIW vias at the center of the couplers’ side wall. Applying this approach minimizes the leakage loss between vias, indicating an improved overall operating bandwidth of 36.31% and 26.32% for Ku-band and K-band, respectively. All vias in both prototypes are realized using an alternative method, without using the Plated-Through-Hole Printed-Circuit-Board (PTH-PCB) machine. In addition, experimental results agree well with the simulated results.

Antipodal Vivaldi Antenna with enhanced gain and improved radiation patterns for 5G-IoT applications using metamaterial and Substrate Integrated Waveguide

An analysis of a novel antipodal Vivaldi antenna (AVA) with constant high gain and enhanced radiation patterns is presented in this paper. The antenna consists of a 1 × 4 AVA array, fed by substrate integrated waveguide (SIW). Next, the corrugations are added to the AVA array with SIW (AVAS) to increase the gain up to 1.5 dBi. Further gain enhancement and radiation pattern improvement are achieved by incorporating square-shaped split-ring resonator (SRR) metamaterial at the aperture of the AVAS array with corrugations (AVAS-C). The designed AVAS-C array with metamaterial (AVAS-CM) provides an enhanced gain of 16.2 ± 0.8 dBi over the 37.9 GHz to 45 GHz frequency range. Also, the proposed AVAS-CM array gives stable radiation patterns. Its front-to-back ratio (FBR) is above 21.3 dB, the sidelobe level (SLL) is below −13.6 dB, and E-plane beam titling is ±1∘. In compact devices, an antenna with low FBR and SLLs is essential to avoid radiations in the wanted directions to alleviate the degradation of electronic components. This paper presents the first time use of the SIW technique for improving the radiation pattern characteristics of the AVA array. Experimental and simulated results show that it is suitable for compact 5G-IoT devices.

Band pass filter size reduction by implementing substrate integrated waveguide technique

Pass Band Filter with precise selectivity is one of the major requirements of MMIC circuits. The major challenge while designing is size. This paper presents a size reduction technique for the Pass Band Filter by implementing SIW (Substrate Integrated Waveguide). The simulated results for the based filter show size reduction as resonance is shifting at the lower side of the frequency range. The passband filter without SIW is having resonance at 8.4GHz with return loss -26dB. After Implementing SIW results show resonance frequency at 7.2 GHz with a return loss of -23.86 dB without affecting the selectivity of the pass band filter. For Design Simulation, Ansys HFSS is used.

Design and packaging of polarization diversity 3D-UWB MIMO antenna with dual band notch characteristics for vehicular communication applications

In this article, the design, fabrication, testing, and packaging of a Substrate Integrated Waveguide(SIW) based polarization diversity 3D eight-port Ultra-Wideband (UWB) MIMO antenna introduced with dual-band notch characteristics for vehicular communication applications. In this proposed UWB MIMO design, we employed a SIW technique to achieve UWB bandwidth with a compact size of 60 × 60 mm3. The SIW based metallic via integrated with L-shaped parasitic slot stub and radiator to notch the WLAN and L-shaped stub connected at the ground plane to notch the X-band. The SIW based radiators are placed in the vertical and horizontal plane to realize the polarization diversity. In addition to providing polarization diversity, the antenna’s direction also contributes a reliable link with communication equipment. The antenna performance metrics such as reflection coefficient(Sii), mutual coupling(Sij), the peak gain, radiation pattern, radiation efficiency, Envelope Correlation Coefficient (ECC), Diversity Gain (DG), Total Active Reflection Coefficient (TARC), Channel Capacity Loss (CCL) and Mean Effective Gain(MEG). The proposed 3D antenna performance analyzed when mounted inside the different types of housing. Hence, the proposed polarization diversity antenna is suitable for vehicular communication applications.

A circularly polarized microstrip patch antenna with enhanced bandwidth based on substrate integrated waveguide techniques

In this article, a circularly polarized (CP) microstrip patch antenna (MPA) is proposed. The antenna adopts a substrate integrated waveguide (SIW) cavity and a microstrip patch as the feed structure and the radiator, respectively. In consequence, the patch dominates the radiation and improves the radiation efficiency, while the asymmetric SIW cavity enhances the bandwidth and generates a pair of degenerate modes, which provide the quadrature phase shift that the CP radiation requires. By this mean, the proposed antenna not only brings up a novel feed structure for CP MPA and improves its effective bandwidth, but also circumvent the limitation of the SIW cavity slot antenna, which is low radiation efficiency. Plus, the presented antenna remains the advantages of SIW structure, including high Q factor, high integrate compatibility, and so forth. The antenna was fabricated and measured, and the presented antenna exhibits an impedance bandwidth of 12% (from 2.09 to 2.36 GHz), an axial ratio bandwidth of 7.73% (from 2.15 to 2.32 GHz) with a minimum gain of 7.89 dB. The experiment results indicate a good agreement with the simulation.

Substrate Integrated Transmission Lines: Review and Applications

This paper presents a general overview of substrate integrated transmission lines, from the perspective of historical background and progress of guided-wave structures and their impacts on the development of microwave circuits and integration solutions. This is highlighted through a technology roadmap involving the categorized five generations of microwave circuits. In particular, the substrate integration technologies are reviewed and discussed with focus on technical features, design highlights, component developments, structures evolution, and systems integration. A number of examples are presented to showcase some of the selected milestone research and development activities and accomplishments in connection with substrate integrated transmission line technologies, with particular focus on substrate integrated waveguide (SIW) techniques. Practical applications and industrial interests are also presented with key references and technical results, which show more and more product developments in the end-user sectors. It can be found that the popularity of SIW techniques is closely related to the achieved seamless integration of planar and non-planar structures into a unified design space, thereby allowing the possibility of combining major advantages of all the structures while alleviating their potential drawbacks. The future perspectives of the substrate integration technology are discussed through five major research directions, which suggest potential impacts in the development of future generations of circuits and systems such as system-on-substrate (SoS).

Compact filtering power divider based on corrugated third‐mode circular SIW cavities

AbstractIn this article, a compact single‐layer filtering power divider based on third‐mode circular substrate integrated waveguide (SIW) cavities is proposed. The third‐mode SIW technique is introduced to divide an SIW cavity into three cavities and get 66% size reduction. The proposed power divider is composed of three third‐mode circular SIW cavities within a circuit with the size of a circular SIW cavity. The power is coupled from the input cavity to two output cavities through the electric coupling, separately. To achieve a more size reduction, the designed cavities are corrugated along the cutting planes. By increasing the length of the corrugated edges, the center frequency can be easily shifted to lower frequencies. In order to prove the proposed design procedure, the presented power divider with a second‐order bandpass filtering response is designed and fabricated. Reasonable agreements between the measured and simulated results are found. The measured results show that the power divider achieves an insertion loss of 1.2 dB at 5.61 GHz, return loss of higher than 14 dB, and 3‐dB fractional bandwidth of 7.8%. The results show that this power divider has the advantages of the compact size, high selectivity, and single‐layer structure.

New miniaturized Wilkinson Power Divider based on a new Half Mode Substrate Integrated Waveguide and CRLH-TL

Objectives: In this study, two new power splitters integrated with a novel half mode substrate integrated waveguide (HMSIW) and composite right/left-handed transmission lines (CRLH-TL) cells are presented, realized and compared to a conventional Substrate Integrated Waveguide (SIW) one. Methods: The SIW technology is characterized by a high Q factor and a low return loss, but it suffers from the massive size particularly in low frequencies bands, so to achieve practically 50% miniaturization in size with keeping the high performances of the SIW technique, HMSIW origins from SIW has been utilized. otherwise, so as to reduce the HMSIW device, size, Composite Right/Left-Handed Transmission Lines (CRLH-TL) cells are applied. The designs are printed on a Roger RT/duroid 6010 and performed within an HFSS environment based on the finite element method (FEM). Simulations and measurements of the three power dividers are presented over a frequency band from 2.2 GHz to 2.6 GHz. Findings: The novel proposed component achieves about 70% and 90% of size reduction compared to, respectively, the HMSIW and SIW power splitters. The simulated and measured results are in close agreement. Application: Compared to the SIW power divider and the HMSIW one the novel proposed device is characterized by a compact size and an easy fabrication process. So that it will enable a convenient reduction of size, loss and cost in millimeter-wave and microwave systems.Keywords: Power Divider, HMSIW, SIW, CRLH-TL Cells, Tapered Transition

Four-Way Filtering Power Divider Using SIW and Eighth-Mode SIW Cavities With Ultrawide Out-of-Band Rejection

A four-way filtering power divider (PD) based on a substrate-integrated waveguide (SIW) is presented. This structure is composed of two layers of the dielectric substrate. The eighth-mode SIW (EMSIW) technique is used to make four cavities in the upper substrate. In addition, an SIW cavity is provided in the lower substrate. To achieve an efficient transition between the two layers, four rectangular slots are etched on the middle metal planes. A circular slot is etched on the top metal layer of the EMSIW cavities to suppress the higher operating modes. To prove the validity, a four-way PD with a second-order bandpass filtering response is designed and fabricated. The measured results show that the PD achieves an insertion loss of 1.3 dB at 3.5 GHz, a return loss of higher than 17 dB, a 3-dB fractional bandwidth of 7.75%, and an out-of-band rejection of greater than 26 dB from 3.92 to 16.5 GHz. The results show that this PD has the advantages of compact size, high selectivity, and ultrawide out-of-band rejection.

Partially Filled Substrate Integrated Waveguide-Based Microwave Technique for Broadband Dielectric Characterization

A novel partially filled substrate integrated waveguide (PFSIW)-based generalized microwave technique for broadband characterization of dielectric materials is presented. The proposed technique is based on the newly derived closed-form analytical formulation to extract the complex permittivity of test specimens placed in the PFSIW structure. The analytical formulations are further improved by developing an empirical model, which especially helps in extracting the loss tangent of the low-loss test specimen in the specified frequency band. The PFSIW structure along with appropriate planar microstrip transition section operating in the X-band region is designed using the full-wave electromagnetic solver, the CST-MWS. The designed substrate integrated waveguide (SIW) structure is fabricated on the commercially available FR-4 substrate, and accordingly, the S-parameters are measured under the unloaded condition which is in close agreement with the corresponding simulated data. Finally, a robust calibration methodology for the PFSIW structure is proposed by designing and fabricating a set of SIW calibration standards, which basically helps to translate the measured S-parameters to the sample interface by removing the effect of microstrip feed section. A number of standard planar RF substrates and dielectric specimens are measured using the designed PFSIW structure, and a close agreement between the extracted permittivity of these samples with their reference values shows the applicability of the proposed SIW technique.

Design of Ku-band power divider using Substrate Integrated Waveguide technique

A Ku-band Substrate Integrated Waveguide power divider is proposed. In this work, the SIW power divider is designed with T-junction configuration. The SIW technique enables the power divider to have low insertion loss, low cost and features uniplanar circuit. An additional of metallic via hole is added in the center of the junction to improve the return loss performance of the Tjunction SIW power divider. The simulated input return losses at port 1 are better than 27 dB, and features equal power division of about -3.1 dB ±0.4 dB at both output ports across frequency range of 13.5-18 GHz. The SIW power divider is fabricated, and the measurement results show acceptable performances. Since there are some losses contributed by the SMA connector of the fabricated SIW power divider prototype, an additional SIW transmission line is simulated and fabricated to analyze the connector loss.

Realization of dielectric loaded waveguide filter with substrate integrated waveguide technique based on incorporation of two substrates with different relative permittivity

In this paper a new structure based on substrate integrated waveguide (SIW), called incorporated substrate integrated waveguide (ISIW), has been used to implement the dielectric loaded waveguide filter in planar structure. Conventional waveguide filter and dielectric loaded waveguide filter have been realized with SIW and ISIW technique, respectively. The use of ISIW structure has reduced the size of the filter, required precision in designing process and the cost of manufacturing process, at the cost of increasing the losses. Thus, while the size of filter and the cost of manufacturing process reduce significantly, there is no need to build the particular dielectric material as resonator and integration with other microstrip devices will be much easier too. Two different excitation mechanism have been considered to cancel the spurious response in the desired frequency band. The SIW and ISIW filters have been fabricated and fairly compared with waveguide filters. Advantages and disadvantages of ISIW structure have been scrutinized in detail. Good agreement between the simulated and measured frequency response of proposed filters has been shown.

Half Mode Substrate Integrated Waveguide Cavity based RFID Chipless Tag

This study presents the design of a compact Radio Frequency Identification chipless tag, with reduced size, important quality factor and improved results. The proposed prototype is based on Substrate Integrated Waveguide technology using the Half-Mode Substrate Integrated Waveguide technique to reduce the tag size by the half and preserve the same response. Further, the operating frequency band is from 5.5 to 8 GHz inside a compact surface of 1.3 × 5.7 cm². The frequency domain approach is adopted based on the frequency shift coding technique.

A novel compact and high performance bandpass filter based on SIW and CMRC technique

Based on the substrate integrated waveguide (SIW) and compact microstrip resonant cell (CMRC) technique, a compact and high performance planar bandpass filter (BPF) is proposed in this paper. The SIW cavity, which has the advantages of high quality and low insertion loss, provides a highpass characteristic. The CMRC structure etched on the top metal plane of the SIW cavity behaves as a lowpass filter, and it can also effectively reduce the dimension of the filter. In order to improve the out-of-band rejection and sharpen skirt selectivity, the open circuit lines at the input and output ports of the filter are introduced. Moreover, the bandwidth and center frequency of the proposed filter can be flexibly tuned by adjusting the cutoff frequencies of the SIW and CMRC separately. As a verification, a representative BPF having a center frequency of 4.54GHz and a 3dB bandwidth of 1.39GHz is designed, fabricated, and experimentally evaluated. The simulated and measured results are in good agreement.

Developing high performance Q‐band planar filters using the multilayered substrate integrated waveguide technique

ABSTRACTIn this article, a novel planar multilayer Q‐band band‐pass filter is presented by cascading a low‐pass filter (LPF)and a high‐pass filter (HPF). The HPF is designed by utilizing the high‐pass behavior of the substrate integrated waveguide, and the LPF is realized by using millimeter‐wave lump‐element resonators. Since the insertion loss resulted by the millimeter‐wave planar resonators, which resonate in‐band and have a limited quality factor, is avoided by using the cascaded high‐/low‐pass architecture, the proposed filter has a small insertion loss. Moreover, a flexible bandwidth can be achieved by properly adjusting the cutoff frequencies of the HPF and LPF. As a demonstration, a band‐pass filter having a center frequency of 42.5 GHz and a fractional bandwidth of 11.76% is designed, fabricated, and measured. Good agreement is obtained between simulated and measured results. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:698–703, 2017

Design and Implementation of a Planar Polarization-Reconfigurable Antenna

In this letter, a planar low-profile 2 × 2 polarizationreconfigurable antenna array using complementary square splitring antenna element based on substrate integrated waveguide technique is proposed for wireless applications. p-i-n diodes are adopted in the design for switching the radiation polarization. Three types of polarizations including linear polarization (LP), left-hand circular polarization, and right-hand circular polarization can be achieved by properly controlling the states of the two p-i-n diodes. A 2 × 2 rotated-element array is developed to demonstrate the feasibility of array application. Prototype of the 2 × 2 antenna array is manufactured and tested. The measured and simulated results verify the performance of the proposed antenna. The measured results show that the antenna array has an impedance bandwidth (S 11 <; -10 dB) of 7.98-8.75 GHz and a 3-dB axialratio bandwidth of 8.18-8.45 GHz for the two CP modes, and has an impedance bandwidth of 8.01-8.24 GHz for the LP mode. The measured maximum gains of the two CP modes and the LP mode are 10.47, 9.9, and 10.75 dBi, respectively. This polarizationreconfigurable antenna has a good performance and a single-layer structure, which can be used for wireless communication systems.

A Collimated Surface-Wave-Excited High-Impedance Surface Leaky-Wave Antenna

This letter presents a novel high-impedance surface (HIS)-based leaky-wave antenna excited by collimated surface wave (SW). The proposed antenna consists of two identical SW launchers (SWLs) and an HIS structure. Regarding the SWL, it is based on an offset-fed parabolic reflector. By using the substrate-integrated waveguide technique, the reflector system is integrated in the planar substrate. For the HIS, it is formed by a periodically arranged rectangular microstrip patch array. The proposed SWL can generate collimated SW with the $\rm {TM_0}$ propagation mode. With the perturbation of the HIS, the guided SW can be transformed to $m$ = $-$ 1 space-harmonic-mode leaky wave. In addition, in order to obtain efficient broadside radiation, an additional secondary slit is properly designed in each unit cell of the HIS to suppress the open-stopband effect. A prototype of the proposed antenna is demonstrated by both full-wave simulation and experimental verification. Continuous beam scan can be realized from $-36^\circ$ to $+35.5^\circ$ within the frequency range of 16–22 GHz.

Low-Profile Circularly Polarized Cavity-Backed Antennas Using SIW Techniques

Two single fed low-profile cavity-backed slot antennas and an antenna array for circular polarization (CP) applications are introduced. By employing the substrate-integrated waveguide (SIW) and half-mode SIW (HMSIW) techniques in antenna designs, low-profile cavity-backed structures are realized using the low-cost standard printed circuit board process. First, a novel spoon-shaped slot antenna is proposed to realize CP radiation based on the SIW cavity. Then, to minimize the antenna size and achieve the impedance bandwidth enhancement, the HMSIW cavity is introduced to realize a cavity-backed semicircle slot antenna (SSA). The equivalence between the edge of the HMSIW cavity and the longitude slot curved on the surface of the SIW cavity is proposed to guide the design process of the SSA. In addition, two hybrid modes are used to improve the impedance bandwidth of the SSA. Furthermore, a sequential rotation antenna array is introduced to validate the feasibility of the SSA for antenna array application. Finally, the proposed antennas and the antenna array are designed and fabricated at 28 GHz. The measured and simulated results agree very well.