X-band Satellite Communication Research Articles

A quad port dual band notch UWB MIMO antenna using hybrid decoupling structure

A four-port dual-band notch ultrawideband (UWB) multiple input and multiple output (MIMO) antenna for automotive applications is presented. Initially, a circular patch monopole antenna is designed and optimized by embedding a rectangular stub onto the radiator and lowering the ground plane to realize the UWB frequency spectrum. The dual-band frequency notch, from 4.6 to 5.9 and 6.8–8.8 GHz, is achieved using a half wavelength slot onto the feedline and a pair of H-shaped stubs across the feedline, respectively, to cover WLAN and complete x-band satellite communication. Further, the designed dual-band notch UWB antenna is transformed to a four-port MIMO antenna with interelement spacing much smaller than λ/4 (λ at 3.1 GHz) and a size of 0.46 × 0.41 × 0.01 λ3. Isolation improvement is achieved by a hybrid decoupling technique comprising a distinctive neutralization line (NL) and defected ground structure (DGS). The average isolation of the proposed design is better than 22 dB. Characteristic mode analysis of the proposed antenna is performed to analyze the specific significant mode and their contribution to the antenna radiation. The antenna design's diversity and time-domain properties are analyzed and found suitable for automotive applications. The antenna's electromagnetic interaction with the electrically large structure is studied by mounting the antenna onto an open-source automobile model, and the gain is determined to be more than 6.1 dB at the antenna's resonant frequencies.

Dual band notched superwideband MIMO antenna for 5G and 6G applications

In this article, a compact super wideband multiple input multiple output (MIMO) antenna with dual band elimination feature is presented. The antenna element comprises of modified square shaped radiating element and coplanar waveguide (CPW) with asymmetric ground planes. A dual-port MIMO configuration is proposed for spatial diversity. It has compact size of dimensions 18 × 37.5 × 1.6 mm3. It has frequency band of impedance matching (VSWR < 2) from 3.9– > 150 GHz (%BW > 189.86 %). The radiator and feedline are loadedwith modified M- and U-shaped slots to achieve a band notch at 5.5 GHz (WLAN) and 7.5 GHz (X-band satellite communication), respectively. A modified staircase shaped structure is used between the two ports to achieve an intraport isolation of > 20 dB at maximum frequencies. The MIMO antenna has envelope correlation coefficient based on scattering parameters < 0.005, envelope correlation coefficient based on farfield parameters < 0.08, peak gain of 8.63dBi, Mean Effective Gain (MEG) < -3dB, multiplexing efficiency > -4.0 dB, channel capacity loss (CCL) < 0.4bits/sec/Hz to signify its suitability for MIMO applications. The measured and the simulated outcomes are found to be close to each other. The proposed antenna element and MIMO antenna structure will be suitable for Internet of Things (IoT), 5G, and 6G due to their superwideband (SWB) bandwidth, desirable radiation properties and diversity performance.

Highly compact UWB-MIMO antenna with sharp multi-stop band characteristics

With multi-band rejection characteristics, a new low-profile antenna of size 34 × 34 mm2 is conferred in this article. It consists of quad identical monopole elements (originated orthogonally), contributing ultra-wideband characteristics in the system. The single unit of the proposed design consists of a modified spinning-top shape radiator (MSTSR), excited by a tapered microstrip line feed (TMLF) and semi-circular ground. An excellent bandwidth of 3–12.9 GHz (where S11 < − 10 dB) is obtained at each port. By inserting the structure of four spiral coils, a sharp notch ranging from 7.9 to 8.5 GHz is achieved to filter the X-band satellite communication uplink. In addition, a circular spiral slot in the radiator near the ground plane creates a stop band at 7.35–7.565 GHz band (satellite communication downlink band). Furthermore, symmetrical rectangular trapezoid resonators and inverted symmetrical rectangular trapezoid structures near the feed line are responsible for the elimination of interferences at 5.5 GHz lower WLAN and 3.5 GHz WiMAX respectively. The FR-4 substrate used for the UWB-MIMO design fabrication process and fabricated results are found in good match with the simulated results. Also, the design provides good performance metrics such as total active reflection coefficient, diversity gain, channel capacity loss, isolation, and envelope correlation coefficient.

Slots and stubs incorporated annular ring-shaped compact microstrip antenna with circular polarization characteristics for wireless UWB communication systems

A circularly polarized (CP) antenna with ultra-wideband resonance and a broad axial ratio bandwidth is designed for UWB communication systems. The prescribed design comprises of a modified annular ring-shaped radiator and a modified step-graded slots loaded partial ground plane. The projected antenna is prototyped on FR4 substrate of 35 × 30 × 1.6 mm3. To achieve wide axial ratio bandwidth, a rectangular vertical slot is inserted into the radiating patch and two stubs are embedded into the monopole ground plane, which is configured with step graded rectangular slots. The simulation results are verified by testing the fabricated protype. The proposed design operates at UWB spectrum with an ultra-wide impedance bandwidth (IBW) of 134.57%, centered at 10.7 GHz, covering 3.5 GHz to 17.9 GHz frequency spectrum. Furthermore, it demonstrates circular polarization characteristics with a broad axial ratio bandwidth (ARBW) of 96.29% expanding from 3.5–10 GHz (6500 MHz). Its peak gain reaches to 8.7 dBi and a maximum radiation efficiency of 95% is achieved within the operating band. The results (measured and simulated) obtained in terms of S11, axial ratio, gain and efficiency and radiation patterns exhibit high agreement. The presented antenna could be a suitable choice for 5.5 GHz Worldwide Interoperability for Microwave Access (Wi-Max), 5.2/5.8 GHz Wireless local area network (WLAN), X-band satellite communication (downlink: 7.25–7.745 GHz, uplink: 7.9–8.4 GHz), UWB communication systems, and other applications in microwave C, X, Ku bands due to its superior characteristics.

Reconfigurable graphene antenna for a network cognitive radio: A novel solution for X-band satellite communications

This study introduces a graphene-based antenna tailored for X-band satellite communication within a cognitive radio network. Leveraging graphene's distinctive traits high conductivity and mechanical flexibility, the antenna design achieves reconfigurability in frequency, polarization, and radiation pattern. This adaptability enables dynamic adjustments to environmental shifts, bolstering the efficiency and dependability of satellite communication. Operating on software-defined radio technology, the cognitive radio system monitors and allocates the available frequency spectrum, allowing real-time adjustments to antenna parameters. Given the widespread usage of the X-band in satellite communications, this antenna proposal stands as an appealing solution for such systems. Its potential applications encompass providing broadband access in remote regions, supporting emergency communication networks, facilitating maritime and aeronautical communications, and enabling self-sustaining wireless networks. The approach involves a novel graphene antenna with slots to facilitate frequency reconfigurability. At 9 GHz, the graphene antenna achieves a gain of 6 dBi, surpassing the 4.3 dBi gain of a copper antenna. By varying the chemical potential of graphene from 0 to 4 eV, we achieved a high gain of 6.4 dBi at 9 GHz and an excellent reflection coefficient of −42 dB at 11.63 GHz. The graphene antenna's improved gain and tuning capabilities surpass traditional materials, showcasing adaptability across diverse frequencies, promising versatility for varied communication needs, and enhancing overall system reliability and effectiveness.

Triple-Band Notched Ultra-Wideband Microstrip MIMO Antenna with Bluetooth Band.

In this paper, a novel ultra-wideband UWB antenna element with triple-band notches is proposed. The proposed UWB radiator element operates from 2.03 GHz up to 15.04 GHz with triple rejected bands at the WiMAX band (3.28-3.8 GHz), WLAN band (5.05-5.9 GHz), and X-band (7.78-8.51 GHz). In addition, the radiator supports the Bluetooth band (2.4-2.483 GHz). Three different techniques were utilized to obtain the triple-band notches. An alpha-shaped coupled line with a stub-loaded resonator (SLR) band stop filter was inserted along the main feeding line before the radiator to obtain a WiMAX band notch characteristic. Two identical U-shaped slots were etched on the proposed UWB radiator to achieve WLAN band notch characteristics with a very high degree of selectivity. Two identical metallic frames of an octagon-shaped electromagnetic band gap structure (EBG) were placed along the main feeding line to achieve the notch characteristic with X-band satellite communication with high sharpness edges. A novel UWB multiple-input multiple-output (MIMO) radiator is proposed. The proposed UWB-MIMO radiator was fabricated on FR-4 substrate material and measured. The isolation between every two adjacent ports was below -20 dB over the FCC-UWB spectrum and the Bluetooth band for the four MIMO antennas. The envelope correlation coefficient (ECC) between the proposed antennas in MIMO does not exceed 0.05. The diversity gains (DG) for all the radiators are greater than 9.98 dB.

Characteristics Mode Analysis-Inspired Compact UWB Antenna with WLAN and X-Band Notch Features for Wireless Applications

A compact circular structured monopole antenna for ultrawideband (UWB) and UWB dual-band notch applications is designed and fabricated on an FR4 substrate. The UWB antenna has a hybrid configuration of the circle and three ellipses as the radiating plane and less than a quarter-lowered ground plane. The overall dimensions of the projected antennas are 16 × 11 × 1.6 mm3, having a −10 dB impedance bandwidth of 113% (3.7–13.3 GHz). Further, two frequency band notches were created using two inverted U-shaped slots on the radiator. These slots notch the frequency band from 5–5.6 GHz and 7.3–8.3 GHz, covering IEEE 802.11, Wi-Fi, WLAN, and the entire X-band satellite communication. A comprehensive frequency and time domain analysis is performed to validate the projected antenna design’s effectiveness. In addition, a circuit model of the projected antenna design is built, and its performance is evaluated. Furthermore, unlike the traditional technique, which uses the simulated surface current distribution to verify functioning, characteristic mode analysis (CMA) is used to provide deeper insight into distinct modes on the antenna.

Selection of Suitable Dielectric Substrate for Miniaturization of Microstrip Patch Antenna Using DGS Fractals

Background: Antennas size reduction with good performance characteristics is an essential part of designing a microstrip patch antenna (MPA) to select a suitable dielectric substrate. Methods: A conventional MPA is designed at 10GHz frequency, and later Minkowski fractal (1st iteration) defected ground structure (DGS) technique is applied for size reduction. The design is made to keep the radiation and reflection characteristics in contention. Results: A miniaturized MPA with 11% size reduction has been simulated using HFSS. The simulation results show the realization and selection of the substrate materials in the design process. Here, five different substrates are judiciously implemented and later compared. The comparison is made based on return loss, bandwidth, impedance, gain and efficiency Conclusion: We found a miniaturized MPA using the proposed first iteration of Minkowski fractal DGS. This MPA is suitable for X-band satellite communication and may be applied in government institutions, civil, military, monitoring weather, air traffic, defence tracking, maritime vessel traffic, etc., due to conformal and planar shape with reduced electrical length at 10GHz operating frequency

Characteristic Mode Analysis-Based Compact Dual Band-Notched UWB MIMO Antenna Loaded with Neutralization Line.

The advancement of electronic gadgets makes it possible for a device to be multipurpose, which calls for attributes such as compactness and larger bandwidth, with improved data transfer rate. This paper introduces the compact, closely placed two-port dual band-notched UWB antenna using a neutralization line as a decoupling structure. The projected antenna design comprised a circle and rectangle embedded monopole radiator with the defected ground structure to attain the UWB spectrum. Further dual notches are attained by carving the U-shape and inverted U-shape slots on the feedline and radiator. The dual band-notched UWB antennas are placed with the separation of 3.8 mm (0.04 λ; λ is computed using 3.4 GHz frequency). The coupling effect between the close proximity elements is decoupled using the neutralization line. The presented antenna has overall dimensions of 21.5 × 28 × 1.6 mm3 (0.24 × 0.31 × 0.01 λ3) and exhibits S11 below −10 dB from 3.4–11.9 GHz, with isolation better than 16 dB throughout the impedance bandwidth. The antenna also provides frequency band rejection of 4.5–5.3 GHz and 7.2–9 GHz covering the WLAN and entire X-band satellite communication. The projected antenna is explored through characteristic mode analysis, time-domain characteristics, and MIMO diversity features to analyze the effectiveness and usefulness of the antenna. The group delay is less than 1 ns except for the frequency rejection band and fidelity factor greater than 0.96. The projected antenna exhibits MIMO diversity metrics ECC < 0.3, DG > 9.6 dB, MEG < −3 dB, TARC < −10 dB, CCL < 0.3 bps/Hz, and ME < −2 dB across the operational frequency, except for the notched bands. The designed two-port antenna is validated by printing on an FR4 substrate. The simulated and measured findings are in line with and appropriate for MIMO wireless applications.

Miniaturized ultra-wideband filter with independently controlled notch bands for 5.1/6/8 GHz wireless applications.

A novel three-mode step impedance resonator (TSIR) is developed to design a miniaturized multi-pole microstrip planar ultra-wideband (UWB) filter with independently controlled notched bands at different frequencies is presented in this work. The basic UWB filter consists of four L-shaped λ/4 short-circuited stubs operating in the range of i.e. 2.7 to 12.1 GHz with fractional bandwidth (FBW) 127%, and the TSIR is constructed using two T-shaped λ/2 open ended step impedance resonator (SIR) and one λ/4 short-circuited uniform impedance resonator (UIR) is coupled to the basic UWB design in order to achieve the stopbands performance at 5.1 GHz, 6 GHz, and 8 GHz, to supress the unwanted bands of WLAN, Wi-Fi 6E, and X-band satellite communication system, respectively. Commercial full-wave electromagnetic (EM) software HFSS-13 was used to design an ultra-compact structure having size 0.07 λg×0.02 λg on Rogers RT/Duroid 5880 substrate to justify good agreement between simulated and measured S-parameters.

Two‐port ring shaped MIMO antenna with quad‐band

This article presents a quad-band multiple-input multiple-output antenna with two-element. Its radiator, composed of four rings, realizes multi-band function, and isolation between the two antenna elements is improved by using the cross-shaped defective ground structure and the goblet shaped stub at the center of the back ground plane. The total size of the design is only 25 mm × 32 mm, but it can obtain good performance in the four frequency bands (4.6-5.0 GHz, 6.82-7.83 GHz, 10.3-10.8 GHz, and 14.1-16.96 GHz), which can be concluded from the simulation and measurement results on the desired bands: (a) the input reflection coefficient (S11) less than −17 dB, (b) the isolation (S21) better than −15 dB, (c) the envelope correlation coefficient below 0.04 and the peak gain greater than 1.23 dBi. The proposed antenna is suitable for wireless communication of small unmanned aerial vehicle operating in the beyond-line-of-sight range. The first of the four bands (4.6-5.0 GHz) is used for 5G cellular network communication and the other three bands can be applied for downlink of X-band (7.25-7.75 GHz) satellite communication, X-band (8-12 GHz) and Ku-band (12-18 GHz) satellite communication, respectively.

Compact Ultrawide Band Metamaterial-Inspired Split Ring Resonator Structure Loaded Band Notched Antenna

A novel compact size ultrawide band planar antenna with band notched characteristics is present. The band rejection characteristic is achieved by loading a pair of metamaterial inspired rectangular split ring resonator (SRR) near the feed line and by etching the SRR slots on a radiating patch. The simulated and measured results reveal that the proposed antenna exhibits the impedance bandwidth over the ultrawide band (UWB) frequency range from 3.1 to 14 GHz with the voltage standing wave ratio less than 2 except for band stop bands at 3.29 to 3.7 GHz (WiMAX band), 3.7 to 4.10 GHz (C-band), 5.1 to 5.9 GHz (WLAN band), and 7.06 to 7.76 GHz (downlink X-band satellite communication), respectively. The proposed antenna fabricated on low-cost FR-4 substrate has compact size of 24 × 20 × 1.6 mm3. The simulation results are compared with measured results and demonstrate good agreement with stable gain over pass bands. The proposed antenna also exhibits dipole-like radiation pattern in E-plane and omni-directional pattern in H-plane. These results led to conclusion that the presented antenna is a suitable candidate for ultrawide band UWB applications with desired band notch characteristics.

Triple band-stop characteristics from an aperture coupled modified Pythagorean tree fractal-based UWB-MIMO antenna integrated with complementary hexagonal spiral defected ground structure

In this manuscript, an aperture-coupled two-port modified Pythagorean tree fractal antenna is modeled and experimentally examined for ultra-wideband applications with triple-band-stop functionality. The proposed array is configured on two 37.5 × 81.5 mm2 FR-4 substrates where the upper substrate incorporates two modified Pythagorean tree fractal radiators and the lower substrate consists a feed network. The notable feature of the proposed Pythagorean tree fractal is the elimination of the base square (0th iteration level) which lowers the total fractal height by 12.11 mm. The multiband response generated by the fractal geometry is extended to a wide operational band by converting the apertures etched from the ground into the hexagonal spiral geometry. The proposed array offers 96.8% fractional bandwidth (3.7–10.64 GHz) with an optimum port-to-port isolation (S21 ≤ −16.1 dB) characteristics. Further, to reject the interfering narrow bands namely downlink C-band satellite communication, WLAN and uplink X-band satellite communication, each feedline is defected with two L-shaped slits, a U-shaped slot and split-ring resonators respectively. Various diversity metrics are investigated which are found to lie within their standard limits. The fabricated prototype (with and without band-notches) is tested and compared with simulated results which show a good similitude, thereby ensuring the feasibility of the proposed array for ultra-wideband and interference rejection operation in a real-world scenario.

An Inset-Feed On-Chip Frequency Reconfigurable Patch Antenna Design with High Tuning Efficiency and Compatible Radome Structure for Broadband Wireless Applications

A novel, dual edge-shaped frequency reconfigurable antenna with a highly compact size is proposed, using microstrip line-based inset-feed mechanism. The presented antenna uses cost-effective ROGER substrate with a thickness of 0.787 mm and has been studied for its gain and radiation pattern in the radome structure presence. The antenna resonates within the range of 3 GHz to 9 GHz approximately, with maximum tuning efficiency of 43 % at 6.5 GHz, covering the major wireless applications of aviation service and wireless local area network (WLAN) in the upper segment of S-band along with worldwide interoperability for microwave access (WiMAX), long-distance radio telecommunications, and X-band satellite communication. The proposed antenna works resourcefully with a reasonable gain of 2.3 dBi at 5.04 GHz, significant bandwidth of 2800 MHz (maximum at 6.5 GHz), directivity, and reflection coefficient. The proposed multiband reconfigurable antenna along with radome structure using ABS material has been investigated under high-frequency simulation environment of HPEEsof of ADS (by Keysight Technologies) and 3d radiation pattern (far-field gain, directivity and power calculations) have been obtained using momentum and EMDS simulators of ADS. The final implementation size (without radome structure) for the patch design comes out to be 23 mm X 26 mm large.

MIMO Dual Sensing Antenna with Notch Characteristics

Design of MIMO antenna with having notch band characteristics between 2.5 GHz-3.7 GHz and 7.7 GHz-8. 6 GHz in the Ultra-wide band operating range from 2.3 GHz-9.96 GHz. For getting notch bands in UWB frequency bands, parallel stubs are kept in the ground to separate the radiating patch elements. The parallel stubs placed in the ground plane improved isolation to 18 dB. The ECC less than 0.01 at the frequency band and the DG is close to 9.5 dB. As the antenna is designed on the flexible polyimide substrate it undergone for bending analysis for different angles like 300,600 and 900. The prototyped antenna measured results providing good agreement with the simulated once obtained from commercial HFSS tool. The obtained band notching characteristics will object some of the frequency applications like WLAN, WiMAX and X-band satellite communication.

WITHDRAWN: A novel WLAN and X-Band rejected elliptical slot loaded metamaterial inspired antenna

Abstract The present study exhibits the frequency rejection at WLAN and X-Band by including square split ring resonator (SSRR) metamaterial structure and elliptical slot. The notched bands have been achieved by incorporating a pair of square split ring resonator (SSRR) metamaterial near the radiating patch and elliptical slot on the radiating patch. The rejection of WLAN band (5.15–5.825 GHz), Downlink X-band satellite communication system (7.36–8.06 GHz) and uplink X-band (9.54–10.38 GHz) has been achieved. The rejected frequencies can be supervised by the tuning the dimension of the metamaterial and elliptical figured slot. The simulated results are obtained by using high frequency simulation software (HFSS). Antenna performance parameters like Reflection coefficient (S11) and gain are obtained and simulated results show favourable radiation efficiency. The radiation patterns and surface current distribution are also obtained at different frequencies.

A compact CPW-fed wideband antenna with circular fractal elements for multiband operations

In this article, a compact flower-shaped CPW-fed antenna is designed for a multiband application. The proposed antenna is created by adding circular fractal elements to edges of the octagon and a slot is created with a similar structure of smaller dimension which is responsible for multiband resonance. The antenna has a compact size of 25 mm × 25 mm, and it exhibits four resonance frequency bands at 2.82 to 6.43 GHz, 7.36 to 8.52 GHz, 11.21 to 12.2 GHz, and 14.05 to 15.83 GHz, respectively. Various antenna characteristics parameters like return loss, VSWR, impedance, radiation pattern, current distribution, substrate material properties are discussed. Antenna design can be used for different applications such as WiMAX (IEEE 802.16), WLAN (IEEE 802.11b, 802.11a/g), INSAT, fixed satellite, ITU band, X-band satellite communication, TV broadcasting, BSS, FSS, and Ku-band.

A compact CPW-fed wideband antenna with circular fractal elements for multiband operations

In this article, a compact flower-shaped CPW-fed antenna is designed for a multiband application. The proposed antenna is created by adding circular fractal elements to edges of the octagon and a slot is created with a similar structure of smaller dimension which is responsible for multiband resonance. The antenna has a compact size of 25 mm × 25 mm, and it exhibits four resonance frequency bands at 2.82 to 6.43 GHz, 7.36 to 8.52 GHz, 11.21 to 12.2 GHz, and 14.05 to 15.83 GHz, respectively. Various antenna characteristics parameters like return loss, VSWR, impedance, radiation pattern, current distribution, substrate material properties are discussed. Antenna design can be used for different applications such as WiMAX (IEEE 802.16), WLAN (IEEE 802.11b, 802.11a/g), INSAT, fixed satellite, ITU band, X-band satellite communication, TV broadcasting, BSS, FSS, and Ku-band.

A compact fractal dual high frequency band notched UWB antenna with a novel SC-DGS

A compact and novel fractal dual band notched UWB antenna with time domain characteristics is presented. A tapered microstrip fed circular fractal radiating patch along with a novel semi circular defected ground structure produce − 10 dB bandwidth from 3.73 to 16.7 GHz. The proposed antenna is a miniature size of 16 × 21 mm2 and is printed on FR-4 substrate with two high frequency notched bands from 7.29–7.76 GHz to 9.53–11.17 GHz to notch X-band satellite communications link by incorporating L and C-shaped parasitic elements respectively. The proposed antenna exhibits a uniform gain of 2–4.26 dBi, flat group delay around 1.2 ns, and peak radiation efficiency about 96% in operating frequencies makes it suitable for wireless UWB portable devices.

A superstrate loaded aperture coupled dual-band circularly polarized dielectric resonator antenna for X-band communications

AbstractA superstrate loaded cylindrical dielectric resonator antenna is developed and demonstrated for dual-band circular polarization. The proposed antenna employs a microstrip-fed rotated cross-shaped slot coupling technique for exciting the dielectric resonator (DR). The design is developed in a straight forward way. Firstly, the DR is coupled with a conventional plus-shaped slot and operates in linear polarization mode at 7.4 and 11.2 GHz. Secondly, the slot is rotated by 10° to enable out-of-phase excitation and ensure circular polarization at the above-mentioned frequencies. In the third step, a square dielectric superstrate is placed above the DR which creates multiple reflection and enhance the gain up to ~8 dBi in both the frequencies without affecting other performances. The development stages are discussed in detail. The proposed design is demonstrated through prototype fabrication and characterization. This antenna can be used for X-band satellite communications.