Substrate Integrated Waveguide Leaky Wave Research Articles

High Gain and Wide-Angle Continuous Beam Scanning SIW Leaky-Wave Antenna

A novel substrate integrated waveguide (SIW) adopting a leaky-wave antenna (LWA) for continuous beam scanning for tri bands is presented. For continuous beam scanning (CBS), optimization of different parameters associated with the unit cell has been carried out. Apart from this, optimal impedance matching is also obtained with the help of the characteristic impedance of the waveguide. The proposed SIW LWA scans from −58° to + 59° along with 14.50 dBi gain when the frequency changes from 10 GHz to 18.22 GHz and provides a scanning rate of 14.23. The beauty of the suggested antenna is its smaller size and high gain, along with a wider scanning range (117°) capability. This antenna’s final prototype has been fabricated, and the measurement results are matched with the simulation results.

A high‐gain miniaturized half‐mode substrate integrated waveguide leaky wave antenna with integrated phase inverter

A <scp>high‐gain</scp> miniaturized <scp>half‐mode</scp> substrate integrated waveguide leaky wave antenna with integrated phase inverter

Multibeam SIW Leaky-Wave Antenna with Beam Scanning Capability in Two Dimensions

This paper presents a 2D multibeam antenna (2D-MBA) for two-dimensional scanning of space with fully passive elements using the substrate integrated waveguide (SIW) leaky-wave antenna (LWA) and Rotman lens for telecommunication applications. An LWA structure with 19 slot elements based on SIW in the frequency range of 14.5–22.5 GHz was designed to scan theta angles from −60 to +35 degrees, and a wideband Rotman lens was designed with five inputs, five outputs, and eight dummy ports to scan phi angles from −30 to +30 degrees. Finally, for two-dimensional space scanning, a five-element SIW LWA array was combined with a Rotman lens, and the whole structure was simulated and implemented in full-wave CST software. By optimizing the structure, the return losses of the input ports were below −10 dB, and the maximum measured gain was 20.3 dBi.

A Novel SIW Leaky-Wave Antenna for Continuous Beam Scanning from Backward to Forward

A novel, periodic, leaky-wave array antenna using substrate-integrated waveguide (SIW) technology is proposed for continuous beam scanning applications. For this purpose, a periodic structure with the ability to radiate from backward to forward is proposed. The unit cell of this periodic structure includes a longitudinal slot and an H-plane discontinuity. The H-plane step discontinuity is suggested to suppress the open stopband (OSB) and enable continuous beam scanning from backward to forward through the broadside. The impedance matching technique is used to suppress the open stopband. In contrast to phased array antennas, this form of antenna is distinguished by its ability to scan without requiring a complex feeding network. These antennas are used for different factors such as scanning the beam, determining the direction of arrival, avoiding collisions, indoor communications, etc. A prototype of the proposed antenna was fabricated for experimental characterization. The overall physical dimensions of the fabricated antenna are 7.9 mm × 128 mm. The results demonstrate that an adequate level of agreement between measurement and simulation is satisfactory. The results indicate that the suggested antenna can scan continuously in the frequency range of 14.5 to 22.5 GHz between −60 and +57.5 degrees through broadside with a maximum gain of 16 dBi and radiation efficiency of 71%.

Substrate integrated waveguide leaky wave antenna with circular polarization and improvement of the scan angle

AbstractIn this paper, a leaky wave antenna is presented based on the substrate integrated waveguide structure. The proposed antenna has a periodic structure with a combination of rectangular and H‐shaped slots on the top of the antenna. By providing this new design for slots, a better angular scanning achieved rather than the previous designs from broadside to end‐fire, so that with this design, the leaky wave antenna can scan from 2.5 to 87° by changing the feeding frequency, which is the highest scanning angle relative to the design of uniform rectangular slots, the butterfly shaped slots and the H‐shaped slots. The proposed antenna was designed to have circular polarization in the entire operating frequency range.

Substrate integrated waveguide leaky wave antenna using longitudinal slots for seamless wide angle scanning with enhanced gain

In this article, a substrate integrated waveguide (SIW) based double longitudinal slots loaded leaky wave antenna (LWA) is presented. Unit cell of the proposed antenna consists of two longitudinal slots with quarter wavelength distance apart from each other for impedance matching at broadside frequency, providing suppressed open-stop band and seamless scanning. Both the slots participate in radiation resulting higher gain. Novelty of the design lies in using two longitudinal slots per unit cell to get higher gain and optimum design to provide wide angle scanning. Dispersion diagram and equivalent electrical circuit have been used to get insight of the behavior of the unit cell. An array of 19 such unit cell of length 11 λ0 (λ0 wavelength corresponds to lowest operating frequency) is used to realize the LWA. The proposed antenna can scan seamlessly from backward to forward direction through broadside with enhanced gain. The antenna can scan 840 (from −640 to 200) with a maximum gain of 16.5 dB and minimum radiation efficiency 66% in the frequency range 10.5 to 17.5 GHz. Finally, a prototype is fabricated, and measurements are done to verify the antenna performances.

Substrate Integrated Waveguide Based Leaky Wave Antenna for High Frequency Applications and IoT

Background &amp; Objective: Internet of things devices managed by wireless networks so that higher data rates can be achieved. With increase in demand of usage of Internet microwave signals are capable for delivering the demand. However these high frequency waves needs a waveguide to propagate otherwise they get affected due to atmospheric attenuation and rain fade. A modified structure of rectangular waveguide is used named as Substrate Integrated Waveguide (SIW). Methods: In this paper, the work has been carried out taking SIW and Leaky Wave Antenna. The dielectric substrate was taken as carbon. Modeling of SIW Leaky wave Antenna is done by making C shaped Slots. Design steps for modeling LWA were orderly pursued also optimized with various equations followed by Finite Element Method based modeling. A range of frequency as input is taken from 7 GHz to 11 GHz to take the analysis of design modeled. Results: The result shows the electric field intensity and radiation pattern is directly proportional with frequency while the return loss is acceptable for applied frequency range. Conclusion: The proposed antenna can radiate in omni directional radiation pattern hence can be used to connect devices with IoT.

Substrate Integrated Waveguide based Leaky Wave Antenna

Leaky Wave Antennas (LWAs) allow electromagnetic wave to leak along its structure. LWAs being low profile have been effortless to fabricate. The SIW can be designed by inserting two rows of metallic via on a dielectric material which work as a wall to prevent the radiation. CRLH property can be generated by cutting the slot on the upper stub which provide the capacitance.In this paper, a periodic CRLH based C-shaped SIW-LWA is proposed which operates in a single band between the frequencies of 13.2 to 15.5 GHz. With the help of SIW and CRLH property designed antenna scans in continuous backward to forward direction with suppressed stop band. This paper shows a substrate integrated waveguide (SIW) based on leaky wave antenna (LWA) including better gain, efficiency and backward to forward beam steering. The periodic C-shaped slot substrate integrated waveguide leaky wave antenna (SIW-LWA) are made-up and the calculated and replicated results acknowledges marvellously. It seems that there is a good contract between them. The beam steering of SIW-LWA is from-60 degree to 29 degree when frequency sweeps from 13.2 GHz to 15.5 GHz. The SIW-LWA offers the peak value of gain as 5.733 dB and peak value of efficiency are 77.545%. The broad side radiation will be at 14 GHz. Below 14 GHz the antenna works as a LH material and scans negative angles and above 14 GHz antenna works as RH material and scans positive angle.This antenna, substrate integrated waveguide leaky wave antenna (SIW-LWA), is proposed only to obtained better beam steering so as to use for such application where beam scanning is used.

Improved Design of Uniform SIW Leaky Wave Antenna by Considering the Unwanted Mode

An improved design for the uniform substrate integrated waveguide (SIW) long slot leaky wave antenna (LWA) is presented in this communication. To achieve the desired sidelobe level (SLL), beamwidth and beam direction, proper distributions for leakage constant and phase constant should be created along the slot. An accurate calculation of leakage and phase constants is performed by considering an unwanted mode, in addition to the leaky mode, along the uniform LWA structure. Considering this unwanted mode in the design procedure results in good consistency between the desired and designed radiation patterns. The presented LWA realizes a Taylor distribution with predefined SLL of -25 dB at 17 GHz. The radiation pattern, amplitude distribution, and phase distribution of the designed antenna are compared with the desired ones. This comparison shows the high accuracy of the proposed design procedure. Measurement results are also presented at 16.5, 17, and 17.5 GHz for validation of the design procedure.

Half Mode Substrate Integrated Waveguide Leaky Wave Antenna with Broadside Gain Enhancement for Ku-Band Applications

Half Mode Substrate Integrated Waveguide Leaky Wave Antenna with Broadside Gain Enhancement for Ku-Band Applications

Compact bilayer substrate integrated waveguide leaky wave antenna with dumbbell‐shaped slot based on the TE 20 mode

In this article, a compact dual layer leaky wave antenna array is simulated and constructed using the substrate integrated waveguide (SIW) based on the TE20 mode at the X- and Ku-bands. The proposed antenna is designed by creating dumbbell-shaped slots on the upper layer of the SIW. These slots have increased the antenna bandwidth so that the proposed antenna has a bandwidth of 9.5 to 13.7 GHz and a fractional bandwidth of 36%. In addition, to excite the TE20 mode, an SIW power divider is used in the feeding network of the antenna located in the bottom layer. Moreover, the gain and directivity are other advantages of the proposed antenna so that at 12.5 GHz the antenna peak gain reaches to 15.7 dB. Antenna beam scanning angle is from 5° to 81°. This antenna is simulated and analyzed by the CST Microwave Studio software. The obtained results from the antenna test lab confirm the simulation results.

Planar SIW Leaky Wave Antenna With Electronically Reconfigurable E- and H-Plane Scanning

This paper reports on a novel technique of switching radiation characteristics electronically between E- and H-planes of planar Substrate Integrated Waveguide Leaky Wave Antennas (SIW-LWAs). The leaky wave mode is achieved through increasing the pitch of bounding metallic via posts on one side of SIW transmission section. The radiation switching is achieved by extending the top and bottom metallic planes to a distance of 1 mm along the leakage side. The extended section acts as a parallel plate section which is conveniently connected or disconnected from the leaking side of SIW through PIN diodes. The `ON' state of PIN diodes extends the metal guides and results in the H-plane leakage whereas `OFF' state of PIN diodes truncates the extended metal earlier and alter the leakage line boundary condition towards E-plane. The whole concept is validated by series of simulations followed by the realization and testing of the SIW-LWA. The measured radiation pattern scans about 54° in the E-plane between 10.0 GHz to 11.7 GHz, and 58° in the H-plane from 9 GHz to 10.6 GHz. The proposed topology is a suitable candidate for remote sensing and airborne applications.

Complementary Split Ring Resonator Loaded Substrate Integrated Waveguide Leaky Wave Antenna

In this paper we present the design of a leaky wave antenna based on Substrate Integrated Waveguide (SIW) loaded by Complementary Split Ring resonator (CSRR). The proposed antenna is designed for 5G application with a center frequency around 28 GHz. The antenna is implemented on Roger RT/Duriod 5880. The loading CSRRs are designed to resonate at 28 GHz. The design is simulated by using both High-Frequency Simulation Software (HFSS) and Computer Simulation Technology (CST) for verification. Experimental measurements are also presented.

Dual-Beam and Tri-Band SIW Leaky-Wave Antenna With Wide Beam Scanning Range Including Broadside Direction

In this letter, a novel dual-beam and tri-band leaky-wave antenna (LWA) based on substrate integrated waveguide (SIW) structure is proposed, which has the capability of wide beam scanning range including broadside direction. The antenna consists of two kinds of periodic structures which can excite two -1st spatial harmonic waves and result in two radiation beams simultaneously. Through theoretical dispersion diagram analysis of the unit cells of two periodic structures and by applying the techniques of impedance-matching and reflection-cancelling, the open-stopbands at broadside are suppressed. Then the main beam of the proposed LWA can scan from backward to forward through broadside when frequency changes. Moreover, a tri-band application can be achieved in the dual-beam antenna by optimization of the second periodic structure. The measured results validate that the proposed SIW LWA has three operating frequency bands. In band 1 from 8.6 to 9.2 GHz, there is one beam scanning from 42° to 71° in the forward, in band 2 from 10 to 12 GHz, there is one beam scanning from -40° to 4° in the backward, and in band 3 from 12.5 to 15 GHz, there is a dual-beam scanning from -55° to 54° including broadside direction, which show good agreements with the simulated results.

Substrate integrated waveguide leaky wave antenna with low cross polarization in X‐Ku band

In this article, a balanced symmetrical low cross polarization (X-pol) substrate integrated waveguide (SIW) based leaky wave antenna (LWA) is presented. The unit cell of the LWA consists of transverse and longitudinal slots, which provide series and shunt resonant elements, essentially required to radiate at broadside direction efficiently. The radiating slots are arranged in a way such that the unit cell is symmetrical around the centerline so as to achieve the low X-pol levels. Moreover, the shape of the longitudinal slots are changed and optimized to match the unit cell impedance to the characteristic impedance of the SIW. Parametric constraints of the radiating slots are studied for achieving the continuous beam scanning and the best low X-pol in the presented LWA. The final presented LWA is capable of continuous beam scanning from −28° to +30° within a frequency range of 9.5-15.2 GHz including broadside at 12.2 GHz. Moreover, the X-pol levels are better than −40 dB all over the scanning frequency range. Finally, the antenna prototype is fabricated and tested. Simulated and measured results are in good agreement. The maximum gain of the antenna measured is 13.8 dB.

Complex beam steering from substrate integrated waveguide leaky wave antenna array

A wideband single-beam/dual-beam leaky wave antenna (LWA) system based on periodic composite right-left handed substrate integrated waveguide is presented in this article. The proposed array can be a good candidate for tracking applications and intelligent protection systems. The system is contributed by installing in parallel two different antenna structures. The first antenna transmits in the frequency band 6.9-11 GHz where the second antenna radiates in the band 8.9-13.8 GHz, the frequencies of the broadside radiation are allocated at 7.8 and 10.2 GHz for the first and the second LWA, respectively. The results demonstrate the potential of the proposed system to continuously steer a single or a dual beams from −72° to 73°. The antenna system has a flexible beam scanning mechanism, good radiation efficiency, and maximum gain of 15.2 dBi. The simulation and the measurement results match well with the theoretical analysis described in the article.

Asymmetric Substrate Integrated Waveguide Leaky Wave Antenna with Open Stop Band Suppression and Radiation Efficiency Equalization through Broadside

Asymmetric Substrate Integrated Waveguide Leaky Wave Antenna with Open Stop Band Suppression and Radiation Efficiency Equalization through Broadside

Substrate integrated waveguide leaky wave antenna with tuned placement of meandering long slot

ABSTRACTThis paper proposes a hybrid method to determine the location and shape of a meandering radiating slot on the substrate integrated waveguide (SIW). At first, different shapes of the long slot are compared with each other to achieve an appropriate shape for a better radiation pattern. Afterwards, the fine-tuned location of the obtained long slot is calculated using curve-fitting techniques. Six-order polynomial and Gaussian functions are applied to approximate the slot coordination on the broad wall of SIW. A leaky wave antenna with the proposed approach is designed and fabricated to establish a 62° beam direction from the broadside of the antenna at 15.9 GHz central frequency and 400 MHz bandwidth. The simulation and experimental results are compared to evaluate the effectiveness of the proposed method. The antenna has a gain about 14 dB and an efficiency of 89% in the desired bandwidth.

CONTINUOUS BEAM SCANNING IN SUBSTRATE INTEGRATED WAVEGUIDE LEAKY WAVE ANTENNA

CONTINUOUS BEAM SCANNING IN SUBSTRATE INTEGRATED WAVEGUIDE LEAKY WAVE ANTENNA

Investigations of SIW Leaky-Wave Antenna for Endfire-Radiation With Narrow Beam and Sidelobe Suppression

A new substrate integrated waveguide (SIW) leaky-wave antenna is investigated for endfire-radiation with a narrow beam and sidelobe suppression. Maximum directivity conditions for endfire-radiation from line sources with different amplitude distributions are theoretically discussed as a design aid. Interestingly, for endfire beams it is seen that designs that have a lower sidelobe level can also have a higher directivity, contrary to what is normally encountered for broadside beams. An SIW leaky-wave antenna with tapered transverse slots on only the top and bottom planes is presented. Compared with a previous leaky-wave antenna having uniform transverse slots on the top plane, the presented leaky-wave antenna has a main beam that can radiate exactly at endfire and also has a lower sidelobe level. The design of the low sidelobe antenna is based on the leaky mode, which loses physical significance as the beam is scanned to the endfire direction. Nevertheless, the antenna retains a good beam shape and a low sidelobe level when it radiates at endfire. A prototype is made, and measured results are consistent with theoretical and simulated results.