Half-mode Substrate Integrated Waveguide Research Articles

Not half bad

Researchers from the Samsung Electronics Network R&D Center in Shenzhen, China, have fabricated and tested a prototype compact substrate-integrated-waveguide (SIW) cavity multiple-input-multiple-output (MIMO) antenna with potential applications in 5G communications. The triangular half mode design achieves an enhanced bandwidth by merging together two coupled modes in the required operating band and boasts high isolation and radiation efficiency. Since it was first introduced a decade ago, SIW technology has drawn significant attention from researchers, with particular appeal in the antenna community. It can be fabricated in planar form using periodic metallic vias and has the advantages of high-Q factor and high-power capacity. In addition to this, cavity antennas resonating at cavity modes and radiating energy through opened cavity edges or etched slots are well-known for good radiation performance. The SIW cavity antenna is an antenna type created by introducing SIW technology into a cavity antenna design. Antennas transmitting and receiving wireless signals are important components in communication systems. The SIW cavity antenna can not only combine the attractive characteristics of conventional cavity antennas, such as good radiation performance and unidirectional radiation pattern, and but also offers the advantages of planar SIW technology, such as low profile, convenient fabrication, and easy integration with planar circuits. Author Bing-Jian Niu in anechoic chamber holding the proposed antenna. Analytical model of the proposed SIW cavity antenna. The SIW cavity antenna reported in the teams published Letter is designed for MIMO applications. By etching three slots, a half-mode SIW cavity was divided into four eighth-mode sub-cavities. Two large sub-cavities are excited by two coaxial ports to construct two antenna elements and cavity energy is coupled from the excited sub-cavities to the unexcited sub-cavities to enhance bandwidth. Thus, a compact two-element MIMO antenna with enhanced bandwidth can be designed and achieved. As is well-known, MIMO antennas have been widely adopted in modern wireless systems. Co-author Bing-Jing Niu, however, notes that: “Two major challenges faced in the design are narrow bandwidth and poor isolation among antenna elements. In our proposed design, three slots are etched in the half-mode SIW cavity. The width, length, and position of these slots are carefully selected in our Letter.” To meet the stringent requirements on antenna fabrication for wearable and portable devices, antenna designs are becoming more and more complex. Compact two-element MIMO antennas with enhanced bandwidth and high isolation are in great demand. With an enhanced bandwidth of 160 MHz, high isolation of 19.5 dB, antenna gain of 4.9 dBi, and radiation efficiency of 72.8%, the proposed SIW cavity MIMO antenna has good specifications and properties, making it suitable for potential applications for forthcoming fifth-generation wireless communications. Etched slots in the antenna provide new perspectives and opportunities for designing SIW cavity antennas, which not only radiate cavity energy into free space but also control the coupling between adjacent sub-cavities. The challenges the group overcome were the ideal selection of slot width, length, and position to optimise their prototype for its intended applications. In the proposed design, a wide rectangle slot is considered as the de-coupler to enhance the antenna isolation while two narrow T-shaped slot are utilised as the coupler to enhance the impedance bandwidth. The novel design makes it possible to increase the channel capacity and link reliability in wireless communication channels. In the short term, this work is expected to be utilised in the sub-6 GHz band. In the longer term, massive MIMO antenna based on SIW cavities will likely be successfully developed and integrated successfully into communication networks. Mr Niu discusses the groups upcoming work and views on the future of the field: “To improve the conformal performance of planar antennas, we are considering liquid crystal polymers (LCP) as a manufacturing substrate. It has the ability to support 3D integration and low tangents up to and including millimetre-wave (MMW) applications. In addition, to improve the MIMO performance, multiple-element MIMO antennas such as four-element and eight-element, have been developed in our own research group. As one of the most pervasive core technologies, massive MIMO antennas will lead to an accelerated pace of research and development in wireless communication with the promise of significant new breakthroughs over the next decade. An unprecedented number of antennas result in major technical challenges as well as new opportunities in antenna design, channel propagation, electronic components and circuit design, and communication theory. We hope the SIW cavity antenna is a good candidate to address this issue.”

Compact SIW cavity MIMO antenna with enhanced bandwidth and high isolation

A compact substrate-integrated-waveguide (SIW) cavity multiple-input–multiple-output (MIMO) antenna with enhanced bandwidth and high isolation is proposed. It is based on a triangle half-mode SIW cavity with one open edge and two edges shorted by metallic vias. By etching three slots, the single cavity can be divided into four eighth-mode sub-cavities. Two large sub-cavities with the same size are excited by two coaxial ports to construct two antenna elements and a wide slot between them is utilised as the de-coupler. Therefore, high isolation can be obtained. On the other hand, cavity energy can be coupled from the excited sub-cavities to the unexcited sub-cavities due to two narrow T-shaped slots serving as the couplers. Therefore, enhanced bandwidth can be achieved by merging two coupled modes into the required operating band. A fabricated prototype centring at 3.51 GHz has been measured. With a compact size of 0.59λ 0 × 0.59λ 0 , enhanced bandwidth of 160 MHz, high isolation of 19.5 dB, the antenna gain of 4.9 dBi, and radiation efficiency of 72.8%, the proposed design has potential applications for fifth-generation communication.

A Novel Quasi-elliptic Bandpass Filter Using Half-mode Substrate Integrated Waveguide Cavities

A fourth-order cross-coupled bandpass filter (BPF) using three half-mode substrate integrated waveguide (HMSIW) cavities and a spurious resonance is proposed. The HMSIW cavity is derived from diamond-shaped SIW; a new spurious resonance mode is built by adding post-wall irises between the two coupled HMSIW cavities and the resonance of spurious mode is analyzed. From the demonstration, an X-band cross-coupled quasi-elliptic filter is designed, simulated, and fabricated. The measured results are in good agreement with simulated results.

A novel super compact half‐mode substrate‐integrated waveguide filter using modified complementary split‐ring resonator

A novel super compact filter based on half-mode substrate-integrated waveguide (HMSIW) technology loaded by the modified complementary split-ring resonator (MCSRR) is proposed. The working principle of the proposed filter is based on the evanescent-mode propagation technique. According to this technique, by loading the complementary split-ring resonator (CSRR) on the metal surface of the substrate-integrated waveguide (SIW) structure, an additional passband below the SIW cutoff frequency can be obtained. In order to miniaturize the physical size of the conventional CSRR, a new method is introduced. In the proposed MCSRR unit-cell, the meander slots are carved inside all of the interior space of the ring. Accordingly, the length of the slot is increased which leads to an increase in the inductor and capacitor of the proposed structure without occupying the extra space. Therefore, the electrical size of the proposed MCSRR unit-cell is reduced. Consequently, the resonance frequency of the proposed MCSRR unit-cell is decreased compared to the conventional CSRR with the same sizes. Namely, the lower resonance frequencies can be achieved by using this technique without increasing the size of the unit-cell. In order to confirm the miniaturization technique, two HMSIW filters loaded by the proposed MCSRR unit-cell are designed, fabricated, and experimental verifications are provided. The results show that a miniaturization about 67% is achieved.

On-chip GaN-on-SiC VCO using a tunable substrate integrated waveguide loaded with complementary split ring resonator

ABSTRACTThis paper presents an S-band voltage-controlled oscillator (VCO) using a tunable half-mode substrate integrated waveguide (HMSIW) loaded with complementary split ring resonator (CSRR) in GaN-on-SiC high-electron-mobility transistor technology. A varactor connected to the center of the outer conductor of the HMSIW-CSRR changed the effective capacitance, resulting in a resonance frequency shift but a fixed transmission zero. Therefore, the S-band VCO can be tuned by the HMSIW-CSRR using harmonic suppression. The tunable HMSIW-CSRR VCO exhibited a frequency tuning range of 3.55–3.98 GHz with a varactor voltage of 0–6 V. The maximum output power was 21.1 dBm and rf-to-dc efficiency was 12.8% at 3.98 GHz. The lowest phase noise was −117 dBc/Hz with 1-MHz offset at a 3.56 GHz carrier frequency with 30.55 dBc of harmonic suppression.

Half‐mode substrate‐integrated waveguide based band‐pass filter for C band application

AbstractDesign and development of half mode substrate integrated waveguide (HMSIW) for a C band application is proposed here. First SIW structure is designed and developed for the cut‐off frequency 5 GHz, and then HMSIW structure is designed and developed from the same structure. Simulated and measured results of both the structures are compared for the verification. A band pass filter (BPF) is designed using HMSIW structure based on transverse slots. Tuning of frequency is carried out by changing the slot length. All the simulation is carried out with the use of high frequency structure simulator (HFSS). BPF provides the pass band from the frequency range of 7.1 to 7.2 GHz with insertion loss less than 2 dB and return loss more than 22 dB. HMSIW structure is further optimized by inserting parallel RLC resonator in between two transverse slots. Measured results are similar with the simulated one.

Compact dual‐mode dual‐band HMSIW bandpass filters using source–load coupling with multiple transmission zeros

Compact dual-mode dual-band bandpass filters (BPFs) with multiple transmission zeros (TZs) using over-mode half-mode substrate integrated waveguide (HMSIW) resonators are presented. Each passband built by TE001 or TE201 has three TZs introduced by source–load coupling and low-/high-order mode cross-coupling between TE001 and TE201 to improve the frequency-selectivity. The equations that determined the TZs are built. Perturbation slots realise the independent-control of frequency ratio. Dual-mode dual-band BPFs are designed, fabricated and measured, and the simulated results agree with the measured results well.

Design and experimental verification of dual‐Fed, self‐diplexed cavity‐backed slot antenna using HMSIW technique

A dual-fed low-profile self-diplexed slot antenna is proposed for 5.2/5.8 GHz applications. The antenna mainly comprises a half-mode substrate integrated waveguide (HMSIW)-based cavity, loaded with a slot and microstrip feedlines. A radiating slot is etched on the upper metal cladding of the HMSIW cavity which splits the cavity into two sections. When each section is excited by using two orthogonally placed feedlines, it generates two frequency bands around 5.2 and 5.8 GHz. By finely tuning the antenna dimensions, a very high isolation of better than 30 dB is realised between the input-ports. Thereby, the proposed antenna exhibits the self-diplexing property. Finally, the proposed antenna is fabricated and the experimentally tested. The experimental results show a close mutual agreement with simulations. Moreover, the antenna shows unidirectional, stable and similar radiation characteristics at both the operating frequencies with maintaining planar configuration. The proposed design provides an easier, compact and a more cost-effective solution for RF front-end components and substitutes the conventional complex diplexer networks.

Wideband HMSIW‐based slotted antenna for wireless fidelity application

In this study, a wideband half-mode substrate integrated waveguide (HMSIW)-based cavity-backed slot antenna is proposed for Unlicensed National Information Infrastructure (U-NII, 5.180-5.825GHz) band. To reduce the size of the antenna, an HMSIW backing cavity is used. An epsilon-shaped radiating slot is etched on the top plane of the cavity to achieve a wide -10dB impedance bandwidth of 13.2% (5.092-5.817GHz). A planar exponential tapered feeding technique is used to excite the slot. A wideband is realised by coupling of hybrid mode, TM 210 mode, and modified TM 020 modes at the resonant frequencies of 5.2, 5.5, and 5.8GHz, respectively. The size of the proposed design including a feeding network is 56mm × 32mm (1.4 λ g1 × 0.8 λ g1 ). The proposed design is fabricated and experimentally tested. The experimental results show gains of 6.6, 6, and 5.5 dBi and efficiencies of 91, 89, and 87% at the frequencies of 5.2, 5.5, and 5.8GHz, respectively, with front-to-back ratio better than 15dB. Moreover, the proposed antenna shows a unidirectional radiation pattern including the advantages of low-profile and lightweight with planar integrity which makes the proposed antenna a favourable candidate for wireless fidelity application.

Tunable Bandstop HMSIW Filter With Flexible Center Frequency and Bandwidth Using Liquid Crystal

This paper reports on a tunable bandstop filter (BSF) with both flexible center frequency and bandwidth. The tunable BSF is based on half-mode substrate integrated waveguide (HMSIW), of which the broadside is coupled with reconfigurable resonators. Using liquid crystal (LC) material as the substrate, a tunable stopband could be obtained by adjusting the bias voltage of the interdigitated microstrip resonator on LC. In order to increase the tunable range of stopband bandwidth, two additional open resonators are implemented at the broadside of HMSIW cavity. For practical validation, the bandstop HMSIW filter using LC is designed and fabricated. Numerical results demonstrate that,by adjusting the voltages of three resonators on LC, either the lower or the higher cutoff frequency could be controlled independently, leading to the flexible and independent tuning ranges of both center frequency from 4.9 to 5.4 GHz and 3-dB bandwidth of stopband from 1.2 to 1.8 GHz (@5.1 GHz).

Low‐profile substrate integrated waveguide (SIW) cavity‐backed self‐triplexed slot antenna

A low-profile self-triplexed slot antenna is proposed for multiple system integrations. The antenna comprises of hybrid substrate integrated waveguide (SIW) cavity (a combination of a half-mode circular and half-mode rectangular SIW), radiating slot, and feeding network. A slot is imprinted on the upper metal-layer of the SIW which splits the cavity into three radiating sections. It offers tri-frequency bands when each section is excited separately. By finely tuning the antenna dimensions, it produces three frequency-bands around 5.57, 7.17, and 7.65 GHz simultaneously utilizes a single slot with maintaining the intrinsic input-port isolation better than 20 dB. This property helps to introduce the self-triplexing phenomenon. Compared with the conventional multiband antennas that use an extra circuitry to ensure the port isolations, this design preserves compactness and easy to integrate with planar circuits Moreover, the proposed antenna is fabricated and the measured results mutually agreed with the simulated counterparts. The proposed design can be a feasible option for mobile transceiver applications.

Half-Mode Substrate-Integrated Waveguides and Their Applications for Antenna Technology: A Review of the Possibilities for Antenna Design

Since its first introduction about a decade ago, the halfmode substrate-integrated waveguide (HMSIW) has gained enormous interest from researchers, with particular appeal in the antenna community. This is essentially due to the offered advantage of size reduction compared to a full SIW but more importantly to the intrinsic availability of an open aperture in the basic geometry. A great amount of effort has been spent on investigating this structure?s characteristics and its potential for integrated antenna designs, which can be efficient up to the millimeter-wave range. This article aims to provide a comprehensive snapshot of the literature on HMSIW antennas, including structure variations, analysis methods, and applications. A broad variety of HMSIW antennas covering a wide range of applications are systematically categorized, namely, into traveling-wave antennas, resonant cavity antennas, and HMSIW-fed antennas. Conclusively, the HMSIW is a versatile structure for numerous antenna applications.

Angular Bend Half Mode Substrate Integrated Waveguide (HMSIW) Based Band-Pass Filter with Multiple Transmission Zeroes

Design methodology of 90° bend half mode substrate integrated waveguide (HMSIW) band pass filter (BPF) is presented in this paper. Edge wall reflections caused due to the waveguide bend has been minimized by providing 135° bend within the waveguide via wall. Array of reactive longitudinal periodic structures are integrated over the HMSIW BPF to obtain transmission zeroes within the pass-band. The elemental properties such as gap between the periodic structure from via wall, gap between group of periodic elements and gap between elemental periodic slots are analysed to formulate their effect over the transmission bandwidth and the stop-band attenuation for each modes of the BPF. Bandwidth > 2 GHz with insertion loss < 1 dB is achieved within all modes of the BPF. The measured results are compared with the simulated outcomes and the concept is validated.

Theoretical and Experimental Investigation of HMSIW-Based High-Speed Data Transmission System Using QPSK Scheme

Half-mode substrate integrated waveguide (HMSIW) is a high-pass transmission line, which can be easily integrated into planar circuits. Compared with SIW, HMSIW features wider relative bandwidth and smaller size. The quadrature phase-shift keying (QPSK) scheme can double the signal transmission rate compared with a simple mixing scheme. In this paper, an HMSIW with 8–24-GHz frequency band is designed and fabricated, and then a high-speed data transmission system using the QPSK scheme is implemented based on the HMSIW. The mathematic modeling of the system is provided to analyze time-domain response and crosstalk of the system, and then accurate control of the amplitude and the phase is realized by the introduction of amplifier and phase shifter. Hence, the amplitude attenuation caused by the loss of the components and phase differences has been compensated, and the crosstalk caused by the phase differences has been eliminated. The above-mentioned modeling is validated by experimental results. Comparisons are also made between the system with and without the amplifier/phase shifter. It is shown that the system can transmit the signal with 15-Gb/s data rate by one physical channel. A high data rate and low bit error rate are obtained in the proposed system.

A novel half mode substrate integrated waveguide leaky‐wave antenna with continuous forward‐to‐backward beam scanning functionality

A half-mode substrate integrated waveguide (HMSIW) leaky-wave antenna with a folded ground is proposed in this article to realize continuous beam scanning from backward to forward direction. This leaky-wave antenna is designed within its scanning region from −27° to 23° as the operating frequency increases from 10 to 14 GHz. In addition, this antenna has a high radiation gain even at broadside. As a folded ground is used to reduce the energy leakage from the open boundary in HMSIW, the transverse size of the proposed antenna could be further miniaturized against other reported HMSIW leaky-wave antennas. Our results show that the radiation gain of the antenna can stably vary from 10 to 11.5 dB by using the open-stopband suppressed technique at broadside. Measured results are found in good agreement with simulated ones over a wide frequency range.

Compact four-element MIMO SIW cavity backed slot antenna with high front-to-back ratio

In this article, a novel design of single layer, compact, multiple input multiple output (MIMO) half-mode substrate integrated waveguide (HMSIW) cavity backed quad element slot antenna with high front-to-back ratio (FTBR) is proposed. The proposed antenna consists of four rectangular SIW cavities with semi-taper radiating slots. The antenna elements are placed in a fashion to achieve high isolation. This antenna is designed for WLAN vehicular communication system to cover the frequency range of 5.84 GHz to 5.96 GHz. It has high front to back ratio (FTBR) of more than 25 dB without using any external metallic reflector. It has more than 37 dB isolation in between orthogonal elements and more than 24 dB in between parallel elements. The envelop correlation coefficient (ECC) and diversity gain are 0.003 and 9.99 dB respectively in between all the elements. Moreover, the antenna has high gain and efficiency of more than 8 dB and 94%, respectively, in 10 dB impedance bandwidth. It can be tuned in a wide range of frequency.

A broadband filter based on hybrid spoof surface plasmon and half‐mode substrate integrated waveguide structure

In this article, a novel design way of wideband bandpass filter (BPF) is proposed. A hybrid sharing waveguide based on spoof surface plasmon (SSP) and half-mode substrate integrated waveguide (HMSIW) is developed. With low-pass feature of SSP and high-pass feature of HMSIW, the proposed waveguide is a BPF naturally and the filter bandwidth can be controlled by adjusting parameters easily. A filter sample is fabricated for verification and the measured 3-dB bandwidth is 46%. The proposed new concept of filter design is attractive and can be used to develop different wideband BPFs.

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.

Miniaturized half mode SIW diplexer loaded by CSRR

This article proposes a novel high-performance and compact size diplexer that implemented by the half-mode substrate integrated waveguide and loaded by complementary split ring resonator. The diplexer operates below the characteristic cutoff frequency of the waveguide. High isolation, low loss, low cost, easy fabrication, miniaturization of size, and integration with other circuits are remarkable attributes of the structure. A higher number of poles and better out of band response causes to give valuable results. Designing steps equivalent circuit, simulation and experimental results are presented. Simulation and measurement results are in good agreement.

Slow-Wave Half-Mode Substrate Integrated Waveguide 3-dB Wilkinson Power Divider/Combiner Incorporating Nonperiodic Patterning

A half-mode substrate integrated waveguide (HMSIW) with developed microstrip polyline unit cells etched on the waveguide surface is investigated in this letter. Modified analysis of the effective electrical parameters analysis is proposed. By applying the modified retrieval method, effective permittivity and permeability are extracted accurately to further describe the influence of the proposed structure, as well as slow-wave effect. Then, a compact 3-dB Wilkinson power divider/combiner based on polyline-patterned slow-wave HMSIW is developed for broadband microwave applications. The prototype achieves a fractional bandwidth of 91.7%, with the amplitude and phase variations less than 0.5 dB and ±4°, respectively. Compared with some reported SIW and HMSIW power divider, this letter achieves a size reduction of 40% and a bandwidth enlargement over 50%, illustrating its suitability for practical broadband applications.