Dual-band Substrate Integrated Waveguide Research Articles

Dual-Band SIW Antenna with High Frequency Ratio for UAV Detection Applications

A dual-frequency antenna based on substrate integrated waveguide (SIW) for unmanned aerial vehicle (UAV) applications is proposed, which provides a new idea for the design of multi-frequency antennas by stimulating multiple high-order modes. A group of fan-shaped patches are added to the circular slots on both sides of the dumbbell slots to form modified dumbbell slots. Two resonant modes are excited by this slot structure, and a dual-frequency response is achieved. Different opening angles and offset angles of fan-shaped patches can cause the deviation of the dual-frequency response bands. Therefore, the antenna working frequency band can be freely designed within a certain frequency band, which improves the flexibility of antenna design. The designed antenna is analyzed theoretically and optimized by simulation. Finally, the antenna was manufactured, and the experimental results were basically consistent with the simulation optimization results. The antenna worked in the X-band and the Ku-band, and the relative working bandwidth of the two bands was 6.06% (9.6–10.2 GHz) and 1.41% (14.06–14.26 GHz), respectively. The maximum gain of simulation in low frequency and high frequency operating bands is 5.9dBi and 6.13dBi, respectively.

Dual-Band Substrate Integrated Waveguide Filters Based on Multi-Mode Resonator Overlapping Mode Control

In this paper, a multi-mode resonator (MMR) overlapping mode control technique is proposed to realize dual-band substrate-integrated waveguide (SIW) bandpass filters (BPFs). A pair of via perturbations and two kinds of slotlines are introduced to control the overlapping modes. Five resonant modes TM110 (a pair of degenerate modes), TM210 (a pair of degenerate modes) and TM020 are perturbed to realize the dual-band filters. The degenerate modes can be rearrange by the via perturbations, and the overlapping modes can be adjusted by the slotlines. Thus, two kinds of dual-band filters can be realized in a single resonant cavity. Then a two-cavity dual-band filter is proposed to realize better out-band suppression and return loss performance. The proposed two-cavity dual-band BPF is synthesized, designed, fabricated, and measured, realizing the 3-dB fractional bandwidth (FBW) of 6.1% and 7.7% at Q-band and V-band, respectively.

Modeling and Analysis of Novel CSRRs-Loaded Dual-Band Bandpass SIW Filters

Dual-band substrate integrated waveguide (SIW) bandpass filter (BPF) operating at 6 GHz and 12 GHz is presented. The two identical complementary split-ring resonators (CSRRs) make up the resonant unit. And the two CSRRs are strongly coupled. For the first time, two resonant units are horizontally etched on the upper metal of SIW. The equivalent circuit model of the novel dual-band SIW BPF is established and analyzed in detail. To realize the miniaturization design of the filter, a dual-band half-mode SIW BPF is proposed. The center frequencies of the passbands are located at 4.56 GHz and 9.36 GHz. The filter exhibits the characteristics of higher slope selectivity, lower insertion loss, wider 3 dB fractional bandwidths and compact size.

Dual-band substrate integrate waveguide slot antenna for 5G applications

The current fifth generation (5G) and millimeterwave technologies are urgently needed to provide huge bandwidth, dual-bands, multi bands, high gain and high directivity radiation pattern beams antennas. However, antennas at millimeterwave suffer from radiation loss and component loss with narrow bandwidth, especially when it is implemented using microstrip structures. Different transmission lines such as waveguide and substrate integrated waveguide (SIW) are studied and introduced for realizing antennas at millimeterwave bands. SIW structures are good candidate for implementation of antenna due to its property of low loss transmission line comprises the properties of microstrip and waveguide technology. However, SIW antennas and structures at millimeterwave have unwanted radiation losses comes from the vias holes. In addition, the vias separation distance is depended on waveguide size, which leads to a bigger size for massive antenna array network at proposed 26 GHz and 28 GHz. Hence, this paper proposed a dual band, compact size, and optimal SIW antenna structure to reduce the vias losses and provides higher bandwidth and gain at 26 GHz and 28 GHz. The proposed design is implemented using three slots to achieve the dual band property and increases the return loss. The proposed design is simulated and studied using CST software. The outcomes of dual-band response at 26 GHz and 28 GHz with a return loss more than 10 dB and a fractional bandwidth of 15% are achieved. A good gain around 8 dB is achieved. These results give a promising solution for realizing a full antenna array based on SIW technology at millimeterwave and 5G technology.

Compact Dual-Band Dual-Mode SIW Balanced BPF With Intrinsic Common-Mode Suppression

In this letter, a compact dual-band dual-mode substrate integrated waveguide (SIW) balanced band-pass filter (BPF) with intrinsic common-mode (CM) suppression is designed by using a single perturbed SIW circular cavity. The vias and slot perturbations are introduced to tune the resonant modes TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">010</sub> , TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">110</sub> (a pair of degenerate modes), and TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">210</sub> of a circular cavity. Thus, they can be used to form two differential-mode (DM) passbands with independently adjustable center frequencies and bandwidths. The SIW can be seen as a natural balun with intrinsic CM suppression. Furthermore, the planar differential excitation structure is designed to excite the perturbed SIW cavity. The CM noise cannot excite SIW cavity due to the characteristics of hybrid electromagnetic boundary. Finally, a compact dual-band dual-mode SIW balanced BPF at 8 and 10 GHz is designed and fabricated, and the measured results show good agreement with the simulated ones.

Compact dual-band SIW filters loaded with double ring D-shaped resonators for sub-6 GHz applications

In this paper, a compact substrate integrated waveguide (SIW) based dual-band filter which utilizes the dual resonance provided by asymmetric double-ring D-shaped resonators that are incorporated on the upper metallic layer of SIW is communicated. The two passbands are generated well below the cut-off frequency of the SIW due to evanescent mode propagation. Such propagation is responsible for the substantial miniaturization of the filter as well. Two types of two-pole dual-band filters are designed that exhibit low insertion loss, wide out-of-band-rejection, compact size, easy fabrication and integration with other microwave components. To validate the proposed idea, three filter prototypes working around 2.66 and 3.54 GHz are designed, fabricated for demonstration and experimentally tested. Parametric analysis is performed to verify the dependence of filter parameters on the proposed filter prototype. Expected agreements are achieved between the experimental and simulated results. The proposed filter finds applications in the upcoming 5G sub-6 GHz communication.

Miniature Dual-Band Substrate Integrated Waveguide Slotted Antenna Array for Millimeter-Wave 5G Applications

A compact substrate integrated waveguide (SIW) antenna array that operates at 28 GHz and 38 GHz is proposed for fifth generation (5G) applications. The proposed array consists of four SIW cavities fabricated on one single layer of substrate. Each cavity implements a rhombic slot and a triangular-split-ring slot, resonating on TE101 and TE102 modes at 28 GHz and 38 GHz, respectively. In comparison with dual-band SIW antennas in the literature, the proposed configuration depicts a miniature footprint (28.7 × 30.8 mm2) without stacking substrates. To excite the four cavities with equal power, a broadband power divider that supports the propagation of TE10 mode is designed. Accordingly, the impedance bandwidths are 26.6–28.3 GHz and 36.8–38.9 GHz. The measured realized peak gain over the lower and higher bands is 9.3–10.9 dBi and 8.7–12.1 dBi, respectively. The measured half-power beam widths (HPBWs) at 28 GHz and 38 GHz are 20.7° and 15.0°, respectively. Considering these characteristics, including dual bands, high gain, narrow beam widths, miniaturization, and single layer, the proposed antenna array is a suitable candidate for millimeter-wave 5G communication systems with the flexibility in switching operating frequency bands against channel quality variations.

A novel dual-band bandpass SIW filter loaded with modified dual-CSRRs and Z-shaped slot

In this paper, a novel dual-band bandpass substrate integrated waveguide (SIW) filter has been presented by loading two modified dual complementary split ring resonators (CSRRs) and a Z-shaped slot on the top side of SIW. The modified dual-CSRR structure is obtained by folding its outer ring, adding T-shaped branch to its inner ring and placing the splits of the inner and outer rings of CSRR in the same direction. The modified structure allows the electromagnetic wave to propagate in the passband below the cutoff frequency of the waveguide. Compared with conventional CSRR of the same size, it has two passbands and work at a lower frequency. A dual-band bandpass filter is proposed by placing two proposed dual-CRSSs face-to-face on the top side of SIW. In order to improve the performance of the filter, the Z-shaped slot is introduced to enhance the electromagnetic coupling, thus increasing the transmission zero point, broadening the passband and enhancing the flatness in the band, and realizing the center frequency shift of the passband to the left. To validate the design and analysis, a dual-band bandpass SIW filter loaded with two modified dual-CSRRs and a Z-shaped slot is manufactured and measured. The first pass band of the filter has a center frequency of 1.94 GHz, a 3 dB band width of 0.28 GHz, the second pass band has a center frequency of 4.85 GHz and a 3 dB band width of 0.13 GHz, which is basically consistent with the simulation results.

Miniaturised substrate integrated waveguide cavities in dual‐band filter and diplexer design

The contribution of this study is to develop a miniaturised substrate integrated waveguide (SIW) cavity resonator with two evanescent-mode resonances. The circuit area of the developed dual-frequency SIW cavity is only 9.2% that of its conventional SIW cavity counterpart. A dual-band filter is implemented from using two miniaturised SIW cavity resonators. The two-passband frequencies can be independently controlled. Two transmission zeros are created by the two sides of each passband for enhancing the signal selectivity. A diplexer is also designed from using the proposed SIW cavities. A dual-band filter and a diplexer are built for experimental verification. Agreements between measured and simulated data are observed. To the best of the authors' knowledge, the designed dual-band filter and diplexer have achieved the best circuit area efficiency in the categories of dual-band SIW cavity filters and diplexers.

Dual-Band (28,38) GHz Coupled Quarter-Mode Substrate-Integrated Waveguide Antenna Array for Next-Generation Wireless Systems

A novel dual-band substrate-integrated waveguide (SIW) antenna array topology is proposed for operation in the 28 and 38 GHz frequency bands. Four miniaturized quarter-mode SIW cavities are tightly coupled, causing mode bifurcation, and yielding an antenna topology with four distinct resonance frequencies. A pair of resonances is assigned to both the 28 and 38 GHz band, achieving wideband operation in both frequency ranges. Moreover, owing to the exploited miniaturization technique, an extremely compact array topology is obtained, facilitating easy and straightforward integration. The computer-aided design process yields a four-element antenna array that entirely covers the 28 GHz band (27.5–29.5 GHz) and 38 GHz band (37.0–38.6 GHz) with a measured impedance bandwidth of 3.65 and 2.19 GHz, respectively. A measured broadside gain of 10.1 dBi, a radiation efficiency of 75.75% and a 3 dB beamwidth of 25° are achieved in the 28 GHz band. Moreover, in the 38 GHz band, the measured broadside gain amounts to 10.2 dBi, a radiation efficiency of 70.65% is achieved, and the 3 dB beamwidth is 20°.

A compact dual-band bandpass SIW filter using uniplanar combination of the CRLH and resonant type metamaterials

ABSTRACTA new manner of obtaining dual bandpass behaviour in substrate-integrated waveguide (SIW) using a uniplanar combination of composite right/left-handed (CRLH) transmission line and complimentary double split single ring resonator (CDSSRR) is presented and analysed in this paper. The proposed dual band structure has the advantage of miniaturisation due to the presence of both the passbands below the characteristic cutoff frequency of the SIW.A high passband transmission zero overcomes the poor frequency selectivity, and the two resonant frequencies are independently controllable. There are very low insertion losses in both passbands as compared to DGS structures and fabrication simplicity is ensured due to an intact ground. The potential for application of the proposed structure to the design of completely planar miniaturised dual band bandpass metamaterial filters has been verified by fabricating a two-stage filter based on the proposed combination. The measured results are in good agreement with the simulation results.

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.

Dual‐band substrate integrated waveguide bandpass filter utilising complementary split‐ring resonators

A novel dual-band substrate integrated waveguide (SIW) bandpass filter (BPF) based on complementary split-ring resonators (CSRRs) is proposed. It consists of an SIW dual-mode cavity loaded by two additional CSRRs on its top layer. Both TE 102 and TE 201 modes in the cavity can be excited by the proper positions of the feeding lines. Two additional CSRRs are etched on the top layer coupled with the TE 102 and TE 201 modes, respectively, to achieve the dual-frequency operation. Four transmission zeros are generated in the vicinity of the passbands to improve the selectivity. To validate the design concept, a dual-band SIW BPF operating at 7.89 and 8.89 GHz is designed, simulated and measured. The measured results are in good agreement with the simulations.

An independently reconfigurable dual-mode dual-band substrate integrated waveguide filter.

In this paper, a novel perturbation approach for implementing the independently reconfigurable dual-mode dual-band substrate integrated waveguide (SIW) filter is proposed. Dual-frequency manipulation is achieved by adding perturbation via-holes (the first variable) and changing the lengths of the interference slot (the second variable) in each cavity. The independent control of the upper passband only depends on the second variable while the lower passband is independently tuned by combining the two variables. Using such a design method, a two-cavity dual-band SIW filter is designed and experimentally assessed with four via-holes and an interference slot in each cavity. The dual-band filter not only has a frequency ratio (fR) ranging from 1.14 to 1.58 but also can be considered as a single passband one with a tunable range of 40.5% from 1.26 GHz to 2.12 GHz. The scattering parameters |S11| and |S21| are in the range of -10.72 dB to -37.17 dB and -3.67 dB to -7.22 dB in the operating dual bands, respectively. All the simulated and measured results show an acceptable agreement with the predicted data.

Dual-Band Dual-Mode Substrate Integrated Waveguide Filters with Independently Reconfigurable TE101 Resonant Mode.

A novel perturbation approach using additional metalized via-holes for implementation of the dual-band or wide-band dual-mode substrate integrated waveguide (SIW) filters is proposed in this paper. The independent perturbation on the first resonant mode TE101 can be constructed by applying the proposed perturbation approach, whereas the second resonant mode TE102 is not affected. Thus, new kinds of dual-band or wide-band dual-mode SIW filters with a fixed or an independently reconfigurable low-frequency band have been directly achieved. In order to experimentally verify the proposed design method, four two-cavity dual-band SIW filters, which have different numbers of perturbation via-holes in each cavity, and a two-cavity dual-band SIW filter, which includes four via-holes and eight reconfigurable states in each cavity, are designed and experimentally assessed. The measured results indicate that the available frequency-ratio range from 1 to 1.3 can be realized by using four two-cavity dual-band SIW filters. The center frequency of the first band can be tuned from 4.61 GHz to 5.24 GHz, whereas the center frequency of the second one is fixed at around 6.18 GHz for the two-cavity dual-band SIW filter with four reconfigurable states via-holes. All the simulated and measured results show an acceptable agreement with the predicted data.

Design of dual band and dual‐polarised dual band SIW cavity backed bow‐tie slot antennas

A novel design technique to implement dual band substrate integrated waveguide (SIW) cavity backed planar slot antenna is presented. The proposed antenna uses a combination of multiple SIW cavities of different size connected through coupling window in the common sidewall of the cavities. The cavities are loaded with long bow tie shaped slots to achieve higher bandwidth of the antenna. The placement of long bow tie slots helps to generate multiple hybrid modes which can be tuned by varying slot dimensions. First, two SIW cavities loaded with bow-tie slots are used to excite four closely placed hybrid modes in X band (8–12 GHz) to realise dual band response with a bandwidth of 600 MHz (7.2%) and 888 MHz (8.74%) and a gain of 5.3 and 4.4 dBi, respectively. The design is further extended using a set of four SIW cavities arranged as two pair of coupled SIW cavities along with bow-tie slots and placed in orthogonal orientation to implement dual band dual polarised slot antenna while maintaining its planar configuration. The proposed antenna exhibits a bandwidth of 390 MHz (3.9%) and 790 MHz (7.29%) with a gain of 6.1 and 5.4 dBi, respectively.

Novel Defected Ground Structure and Two-Side Loading Scheme for Miniaturized Dual-Band SIW Bandpass Filter Designs

This letter reports a novel back-to-back E-shaped defected ground structure (DGS) and two-side loading scheme for miniaturized dual-band substrate integrated waveguide (SIW) bandpass filter (BPF) designs. The SIW loaded by novel DGS supports evanescent-mode wave propagation below the cut-off frequency of SIW, while achieves two transmission poles at the passband and two controllable transmission zero points. Furthermore, the novel loading scheme by loading different-sized DGS resonators on two sides of SIW is proposed for dual-band BPF designs. To validate the design and analysis, a 2.4/5.2 GHz filter prototype was designed. In good agreement with theoretical results, the measured results of the dual-band filter achieve insertion losses of 3.6 and 3.1 dB, and fractional bandwidths of 5.8% and 6.45% at 2.4 and 5.2 GHz, respectively. The filter size is only 408 mil × 420 mil.

A compact dual-band bandpass SIW filter

A novel method for the design of substrate integrated waveguide (SIW) dual-band bandpass filter is presented in this paper. Dual-band response is achieved by TE101 mode and diagonal TE201 (TE102) mode. The resonant frequency of TE101 mode can be adjusted by the location of perturbation vias while the resonant frequency of diagonal TE201 (TE102) mode keeps unchanged. A design example with second-order filter response is given and verified by experiments. The vertically stacked SIW resonators are used here to save the size.