Proposed Ultra-wideband Antenna Research Articles

Investigations on Input Impedance and Radiation Pattern of a UWB Antenna for Microwave Imaging

Investigations carried out on the Input Impedance and Radiation Pattern of an Ultra-wideband (UWB) antenna are presented in this study. The proposed antenna is fabricated on an FR4 printed circuit board with a rectangular aperture. Major applications of UWB technology are presented. The fundamental characteristics of the antenna, such as input impedance, return loss, radiation pattern, and realized gain, are obtained. Investigations on how to improve the directivity of the proposed antenna are also presented in this study. The antenna demonstrates good impedance bandwidth (S11≤ -10dB) from about 4GHz to 10.6GHz, except in the case when the width _W_ of the T-shaped stub was varied. A commercial simulation tool – CST Microwave Studio – is used for the optimization of the proposed antenna. The proposed antenna operates almost over the entire UWB band (3.1-10.6GHz), except at lower frequencies of 3.1-4GHz. The response of the designed UWB signal starts at 3.1-10.6GHz, giving a good performance between 4GHz to 10.6GHz with an operational bandwidth of 6.6GHz. The input impedance is well matched, as a return loss of 10dB is obtained between 4-10.6GHz. The return loss decreases even more at 4-5GHz and at 8-10GHz, which means that the proposed UWB antenna transmits a high percentage of its power while a very low power is reflected back.

A novel octagonal slot circular compact ultrawideband antenna with detailed frequency and time-domain analysis

With time, the device's reliance on wireless communication and its users grows tremendously. The ultrawideband (UWB) technology offers a 7.5 GHz uncontrolled bandwidth. Because it allows for larger data rates over a short distance, UWB technology is the current and future requirement of new generation mobile networks. As a result, a novel octagonal slot circular compact UWB antenna with detailed frequency and time-domain analysis is proposed in this research. Throughout the UWB range, the hexagonal-shaped circular radiator aids in reaching better S11 parameters (S11-10 dB). The modified trapezoidal like partial ground plane allows for a wide bandwidth. The proposed UWB antenna operates at frequencies ranging from 3.2 to 13.1 GHz, allowing for a bandwidth of 9.9 GHz and a fractional bandwidth of 121.4%. Voltage standing wave ratio (VSWR) is seen to be in the range of 1 to 2 throughout this UWB range. Throughout the operational bandwidth, the antenna's gain ranges from 2.8 to 4.1 dB. The suggested UWB antenna has the advantages of being small, having superior impedance matching, a simple design, and having a high gain, all of which can be used to deploy the antenna for the aforementioned purposes.

Design and analysis of a super compact UWB antenna for accurate detection of breast tumors using monostatic radar‐based microwave imaging technique

AbstractThis article proposes a low‐profile ultra‐wideband (UWB) antenna for breast tumor detection using the monostatic radar‐based microwave imaging (RBMI) technique. The proposed UWB antenna consists of a circular patch and ground plane along with a modified tapered feed line having a total size of 13 × 9 × 1.6 mm3. The designed antenna operates from 4 to 11 GHz based on a −10 dB reflection coefficient with a peak gain of 9.5 dBi at 4.8 GHz. Experimental validation is carried out after fabricating the prototype of the UWB antenna and the breast mimic. The measured backscattered signals are captured using the vector network analyzer (E‐5063A) by keeping the antenna at 10 mm from the breast phantom. After that, post‐processing of the measured data is done to detect the exact depth and location of the malignant tissue. The proposed antenna uses UWB band frequency of operation because it has some unique features, that is, it provides immunity to multipath fading, has a simple design, has a low cost of fabrication, and has biological friendliness. Moreover, due to the proposed antenna's resonance at a lower resonant frequency better depth of penetration is achieved in human body phantoms and the proposed antenna provides specific absorption rates (SAR) of 0.877 W/kg over 1 g of tissue at 4.8 GHz, which is an acceptable limit for SAR as per FCC guidelines. Therefore, the proposed antenna and monostatic RBMI technique are good candidates for breast tumor detection.

Bandwidth and Gain Enhancement of a CPW Antenna Using Frequency Selective Surface for UWB Applications

In this article, a single-layer frequency selective surface (FSS)-loaded compact coplanar waveguide (CPW)-fed antenna is proposed for very high-gain and ultra-wideband applications. At the initial stage, a geometrically simple ultra-wideband (UWB) antenna is designed which contains CPW feed lines and a multi-stub-loaded hexagonal patch. The various stubs are inserted to improve the bandwidth of the radiator. The antenna operates at 5-17 GHz and offers 6.5 dBi peak gain. Subsequently, the proposed FSS structure is designed and loaded beneath the proposed UWB antenna to improve bandwidth and enhance gain. The antenna loaded with FSS operates at an ultra-wideband of 3-18 GHz and offers a peak gain of 10.5 dBi. The FSS layer contains 5 × 5 unit cells with a total dimension of 50 mm × 50 mm. The gap between the FSS layer and UWB antenna is 9 mm, which is fixed to obtain maximum gain. The proposed UWB antenna and its results are compared with the fabricated prototype to verify the results. Moreover, the performance parameters such as bandwidth, gain, operational frequency, and the number of FSS layers used in the proposed antenna are compared with existing literature to show the significance of the proposed work. Overall, the proposed antenna is easy to fabricate and has a low profile and simple geometry with a compact size while offering a very wide bandwidth and high gain. Due to all of its performance properties, the proposed antenna system is a strong candidate for upcoming wideband and high-gain applications.

Design and Analysis of Impulse Radio (IR) Based UWB Transmitter with Antenna

The use of ultra-wideband (UWB) in target detection, radar and wireless connectivity, specifically in the medical world, has attracted a lot of attention. The concept that the IR-UWB system does not necessarily require carrier signals is one of its most appealing features. IR-UWB can transmit information using short Gaussian monocycle pulses. In light of these advantages, this paper proposes a novel UWB transmitter system which consists of UWB signal generating circuits and UWB antenna, which work together to create entire UWB transmitter. It is based on impulses and has a simple architecture with low power consumption. The proposed transmitter is realized in Cadence tools with 90nm CMOS technology and proposed UWB antenna is simulated using Advanced Design System (ADS) simulator software. In addition, the transmitter circuit and the antenna are co-simulated using ADS software. The illustrated UWB transmitter uses a low-power supply and generates pulse amplitude with pulse duration of for the Gaussian monocycle pulse. Due to its increased output voltage swing and reduced power consumption when comparing to other circuits, the proposed architecture is functional and suitable for use in short-range wireless networks and medical applications.

Design of Compact Monopole Antenna with U-Shaped Defected Ground Structure (DGS) for UWB Application

This paper described the design of a compact printed monopole antenna with U-shaped Defected Ground Structure (DGS) for ultrawideband (UWB) application. The implementation of DGS facilitates in reduction of size and increases in antenna performance. The DGS and antenna design parameters are simulated using CST Microwave Studio 2020, and the measurement is carried out using R&S Vector Network Analyzer (VNA). The optimized design of the proposed UWB antenna with U-shaped DGS presented smaller in size (23.88mm x 29.10mm x 0.813mm) with a reduction of 32% compared to the conventional design, which fabricated on Rogers RO4003C substrate with a relative permittivity, εr = 3.38. Simulation results show that the proposed antenna provided a very wide range of frequency (3.2 - 20GHz), 144.8% of BW. The simulated and measurement results show good agreement.

Design of UWB Antenna for Multimedia and High-Speed Automotive Communication

This paper reveals a planar ultra-wideband (UWB) antenna with defective ground structure is designed and analyzed. A size of 24 × 24 × 1.6 mm3 circular shaped proposed UWB antenna uses FR-4 substrate covering the impedance bandwidth (S11 ≤ −10 dB) of 11 GHz ranging from 2.9 GHz to 13.9 GHz and also offers a peak gain of 5.1 dBi, more than 65% of efficiency in overall UWB operating band with omnidirectional radiation pattern. The simulated results of proposed UWB planar antenna have good performance, and is well-suited for high-speed and multimedia communications in vehicular environment.

SAR Evaluation of Flexible UWB Antenna for Wearable Applications

This manuscript appearance a compact and Ultra-Wideband (UWB) antenna for wearable applications. The proposed coplanar waveguide (CPW) feed circular configuration patch antenna is simulated on two different dielectric materials one flexible polyamide based Cordura fabric and other is FR-4, with small footprint of size 36 × 46 mm2. The antenna works in complete UWB band from 3.1 to 10.6 GHz. The performance of the antenna was examined in free space and three-layer human body phantom. This research work also presents the flexibility analysis of structure for both substrates. These examinations exhibited that proposed UWB antenna is an appropriate contender for wireless body area network (WBAN) operation.

A Compact Triple-Band UWB Inverted Triangular Antenna with Dual-Notch Band Characteristics Using SSRR Metamaterial Structure for Use in Next-Generation Wireless Systems

A compact triple-band operation ultra-wideband (UWB) antenna with dual-notch band characteristics is presented in this paper. By inserting three metamaterial (MTM) square split-ring resonators (MTM-SSRRs) and a triangular slot on the radiating patch, the antenna develops measured dual-band rejection at 4.17–5.33 GHz and 6.5–8.9 GHz in the UWB frequency range (3–12 GHz). The proposed antenna offers three frequency bands of operation in the UWB range, which are between 3–4.17 GHz (~1.2 GHz bandwidth), 5.33–6.5 GHz (~1.17 GHz bandwidth), and 8.9–12 GHz (~3.1 GHz bandwidth), respectively. The higher resonating frequency band can be tuned/controlled by varying the width of the triangle slot, while the medium operational band can be controlled by adjusting the width of the SSRR slot. Initially, the simulated S-parameter response, 2D and 3D radiation patterns, gain, and surface current distribution of the proposed UWB inverted triangular antenna has been studied using epoxy glass FR4 substrate having parameters εr = 4.3, h = 1.6 mm, and tan δ = 0.025, respectively. In order to validate the simulation results, the proposed UWB antenna with dual-notch band characteristics is finally fabricated and measured. The fabricated antenna’s return-loss and far-field measurements show good agreement with the simulated results. The proposed antenna achieved the measured gain of 2.3 dBi, 4.9 dBi, and 5.2 dBi at 3.5 GHz, 6.1 GHz, and 9.25 GHz, respectively. Additionally, an in-depth comparative study is performed to analyze the performance of the proposed antenna with existing designs available in the literature. The results show that the proposed antenna is an excellent candidate for fifth-generation (5G) mobile base-stations, next-generation WiFi-6E indoor distributed antenna systems (IDAS), as well as C-band and X-band applications.

A detailed performance analysis of a novel UWB flexible monopole antenna realized with airbrush technique for different technologies

In this article, a detailed performance analysis of a novel flexible monopole antenna with a 141.46% impedance bandwidth in the 2.4–14 GHz ultrawideband (UWB) range is present. The antenna is fabricated on a flexible Kapton substrate with compact geometry for different technology applications under different bending conditions. The airbrush printed technique was preferred due to its advantages such as easy production, conductivity control, and no loss of surface waves. The antenna has dimensions of 82 × 57 × 0.125 mm3 and is fed by a coplanar waveguide transmission line. All necessary antenna simulations are performed using Computer Simulation Technology (CST). According to the positions of identical antennas face to face, face to side, side to side, time-domain analysis is performed for the impact response analysis. The transmission coefficient characteristics (S 21) and the group delay are measured for various bending conditions. Time and frequency domain analyzes show that the proposed UWB antenna has the much-needed stable performance in UWB antenna. The proposed UWB antenna has good performance over the operating spectrum for a flat and bending configuration.

Compact reconfigurable antenna system for spectrum interweaved cognitive radio

This article discusses the design of a compact antenna system for spectrum interweaved cognitive radio (CR). The system consists of a sensing filtenna and three communicating antennas. The sensing ultra-wideband (UWB) antenna is a coplanar-waveguide (CPW)-fed monopole (2.2–11 GHz). The narrowband communicating patch antennas are reconfigurable through a switching mechanism, operating in six different frequency bands (5.54, 6.12, 7.60, 8.25, 9.64, and 10.29 GHz). To block the Wi-MAX and WLAN bands, the proposed design uses a meandering slot and a stepped U-slot in the monopole. Analysis of communicating antennas using the theory of characteristic mode analysis indicates good radiation in the desired frequencies. Isolation among these antennas is better than −18 dB. A constant group delay and linear phase response indicate a good time-domain performance of the proposed UWB antenna. Simulated results match closely with those from measurements on the prototype. The proposed antenna system can find applications in various sectors adopting CR like internet of things.

Design of low profile high gain antenna using loop-based wideband artificial magnetic conductor for UWB applications

AbstractIn this work, a low profile ultra-wideband (UWB) antenna is designed and investigated using a novel loop-based wideband artificial magnetic conductor (WB-AMC) for gain enhancement. Initially, a compact loop antenna is designed using stub loading and further optimized for the UWB range by applying curve ground methodology. The average gain of the proposed antenna without WB-AMC is 2.7 dBi. To enhance the gain of the entire UWB range, loop-based WB-AMC in [2 × 2] forms is integrated. WB-AMC is used as a ground plane beneath the antenna. To validate the performance, the UWB antenna and WB-AMC are fabricated and tested. The measured results confirm the entire UWB range. Proposed antenna provides a peak gain of 9.4 dBi and an average gain of 5.8 dBi. Vertical profile reduction of 50% is achieved compared to perfect electric conductor ground. The proposed UWB antenna is a potential candidate for UWB wireless applications due to its attractive features such as low profile, wide bandwidth coverage, omnidirectional pattern, constant high gain, and group delay.

Early detection of acute coronary syndrome through prothrombin time measurement using flexible UWB antenna for cardiac patient

Acute coronary syndrome (ACS) is the disease occurs due to clot formation in heart arteries. The prothrombin time (PT) of the blood measures various health disorders such as liver dysfunction, cardiac function, internal bleeding and internal blood clots. The PT measurement through optical and mechanical coagulation analyzers is influenced by plasma turbidity, reagent sensitivity and vitamin K levels. In this paper a novel method for early detection of ACS through PT measurement using flexible ultra-wide band (UWB) antenna is proposed. This study is carried on 200 persons with and without ACS. In the proposed method the electromagnetic radiations absorbed from the plasma sample using flexible ultra-wide band antenna is processed further to determine the prothrombin time. The plasma concentration is proportional to electromagnetic energy density and based on the voltage clotting duration is acquired. The clotting frequency ranges of human blood varies from 2 GHz to 3 GHz and voltage from 0.55 mV to 0.85 mV in the observed electromagnetic radiation. The clot concentration is measured from the observed electromagnetic emitted voltage which is converted into frequency during clotting. The prothrombin time is measured from the acquired clotting concentrated voltage through regression modelling and validated through laboratory standards. The proposed UWB antenna based prothrombin time measurement achieves 96.48% accuracy in detecting ACS at the early stage The variations in PT values, need for reagents, vitamin-K impacts, and plasma turbidity impacts were eradicated in the proposed method and ACS is detected early from the measured PT values.

High Gain of UWB Planar Antenna Utilising FSS Reflector for UWB Applications

In this paper, a high gain and directional coplanar waveguide (CPW)-fed ultra-wideband (UWB) planar antenna with a new frequency selective surface (FSS) unit cells design is proposed for UWB applications. The proposed UWB antenna was designed based on the Mercedes artistic-shaped planar (MAP) antenna. The antenna consisted of a circular ring embedded with three straight legs for antenna impedance bandwidth improvement. The modelled FSS used the integration of a two parallel conductive metallic patch with a circular loop structure. The FSS provided a UWB stopband filter response covering a bandwidth of 10.5 GHz, for frequencies from 2.2 to 12.7 GHz. The proposed FSS had a compact physical dimension of 5 mm × 5 mm × 1.6 mm, with a printed array of 19 × 19 FSS unit cells. The FSS unit cells were printed on only one side of the dielectric FR4 substrate and placed as a sandwich between the antenna and the reflector ground plane. An equivalent circuit configuration (ECC) was used to verify the FSS unit cell structure’s performance. The simulated results indicated that the UWB MAP antenna and FSS reflector provided a fractional bandwidth of 136% and a high gain of 11.5 dB at 8.5 GHz with an acceptable radiation efficiency of 89%. Furthermore, the gain was improved across the operating band and kept between 8.3 and 11.5 dB. The proposed antenna was in good agreement between theoretical and experimental results and offered a wide enough bandwidth for UWB and vehicle applications.

A Compact Dual-Band Notched UWB Antenna for Wireless Applications

This article presents the design and analysis of a V-shaped ultrawideband (UWB) antenna and dual-band UWB notch antenna. A rectangular slot is cut into a semicircular partial ground plane of the antenna to achieve ultrawide bandwidth. A U-shape slot is etched on a V-shaped patch that radiates, and an inverted U-shape parasitic resonator is placed beside the feedline to generate dual-band notch characteristics. The overall dimension of the proposed antenna is . The proposed UWB antenna has a gain of 9.8 dB, S11 < −10 dB, impedance bandwidth in the range of 3.4 to 12.3 GHz, response with a linear phase, group delay <1 ns, and stable radiation pattern. The UWB notch antenna shows strong rejection in the WLAN band from 5.15 to 5.8 GHz with a notch at 5.6 GHz and X band from 9.1 to 10.5 GHz with a sharp notch at 9.6 GHz, having a S11 < −10 dB impedance bandwidth ranging from 3.2 to 11.7 GHz. This antenna also exhibits a stable radiation pattern, group delay <1 ns, and linear phase response throughout the bandwidth except at the rejection frequencies.

Sprocket gear wheel shaped printed monopole ultra‐wideband antenna with band notch characteristics: Design and measurement

A compact ultra-wideband (UWB) printed monopole UWB with dual band-notched characteristics has been designed and investigated in this manuscript. The Wi-MAX and wireless local area network (WLAN) band rejection characteristics have been obtained by employing the circular ring and arc-shaped slot along with rectangular slot in radiating patch. Overall size of proposed UWB antenna is 27 × 27 × 1.6 mm3, which consists of sprocket gear wheel shaped structure as a core radiating patch element and excited by using 50 Ω coplanar waveguide feed. The proposed antenna exhibits the UWB frequency spectrum from 3.1 to 10.6 GHz along with Bluetooth frequency range 2.4–2.48 GHz without disturbing overall dimensions of antenna. Proposed antenna reveals the measured VSWR operating bandwidth of 10.0 GHz in the frequency range from 2.0 to 12.0 GHz along with Wi-MAX and WLAN rejected bands. Moreover, proposed antenna adorns the measured gain of −8.28 and − 9.98 dBi at rejected frequency bands, whereas, at other frequencies, it changes between 1.5 and 5.0 dBi. The radiation efficiency of proposed UWB antenna varies from 84% to 97% except rejected frequency bands. Group delay and radiation pattern have also been analyzed and found appropriate for the current UWB applications. Finally, the optimized structure of antenna with dual band rejection characteristics has been fabricated and tested for the authentication of simulated results. Both the results are compared and are found in good agreement with each other.

Design a new notched UWB antenna to rejected unwonted band for wireless communication

This paper presents a slotted design for ultra-wideband (UWB) antenna. Design of a rectangular UWB antenna covering the frequency range 3.1-10.6 GHz, to achieve notch characteristics in the bands at 3.1-8.4 GHz and 8.6-10.6 GHz. By changing the direction of distribution of current to apply this technique by inserting three C-shaped holes and two pairs of rectangular notches below the antenna. The simulation results reveal that the proposed structure is in good accord with the simulation results. The proposed UWB antenna size is (100x90x1.6 mm) 3 . This proposed design could provide a solution to eliminating bands that interfere in a UWB band depending on the aperture design. The simulated findings reveal that the UWB antenna operates in the 8.5 GHz center frequency range and rejects all frequency bands utilizing slits. This antenna design can provide a solution to remove UWB bands from 3.1-10.6 except for 8.5 GHz which only works. By using the notch, we got a large increase in the gain. makes to be a suitable candidate for X-band-UWB applications.

Infinite length slotted ultra-wideband monopole antenna using step-feed with band notch characteristics

AbstractIn this work, a printed ultra-wideband (UWB) antenna has been proposed exhibiting band notch characteristics. The proposed design covers the entire UWB band except for the 3.5 GHz band providing the band notch for the WiMAX band. This design consists of two-quarter elliptical patches placed symmetrically over the FR4 substrate. The elliptical shape of the patch is responsible for the UWB band achieved. The slot has been created on the optimized patch area to achieve the desired characteristics providing a notch for the WiMAX band. The slot in the patch is so perfectly designed that it gives the patch a perfect shape of butterfly wings. After designing, the proposed antenna was simulated and then fabricated. The fabricated and simulated results are in close agreement with each other which shows, the proposed UWB antenna is good enough for biomedical applications.

A simple frequency selective surface structure for performance improvement of ultra‐wideband antenna in frequency and time domains

This article demonstrates a new type of annular ring shaped cylindrical dielectric resonator (ARCDR) loaded printed ultra-wideband (UWB) antenna which is further loaded with a new type of two-layer UWB frequency selective surface (FSS) structure. The proposed FSS helps to improve the peak gain of the standalone hybrid antenna significantly (about 4.45 dB). The proposed FSS loaded hybrid antenna provides measured impedance bandwidth (IBW) and measured peak gain about 115.5% (S11 ≤ −10 dB, 3.75 to 14 GHz) and 10.3 dBi respectively. The top layer of FSS structure employs a square loop configuration integrated with “+” sign, staged in 45° angle. Bottom layer of FSS consists of a square loop. The standalone proposed FSS structure also provides large transmission (S21 ≤ −10 dB, 108%, measured) bandwidth (BW) from 3.5 to 11 .75 GHz. The behavior of the proposed UWB antenna geometry has been studied in both frequency and time domains. The newly proposed FSS structure and integrated antenna have been fabricated and there is a close agreement between the simulated and the measured performances.

UWB dual-notched planar antenna by utilizing compact open meander slitted EBG structure

In this paper, an ultra-wideband (UWB) dual-notch planar antenna is presented. The antenna, in its structure, utilizes a compact electromagnetic bandgap (EBG) structure with new open meander slits to notch two frequency bands at around 3.5 and 5.5 GHz. The main idea is to place the new slitted mushroom-type EBG structure at the vicinity of the feedline to achieve filtering ability for the antenna. The presented EBG structure has many benefits, like notched bands with sharp roll off, independent control over the notched bands, little effects on antenna performance, easy switching configuration and reduction of the required number of EBG cells. The fabricated antenna shows −10 dB bandwidth of 2.63 up to 13 GHz with dual-notched in the frequency bands of 3.11–4.01 GHz and 5.15–5.98 GHz. Simulation and experimental results exhibit a close agreement with each other. The proposed UWB antenna with a flat transfer function and a constant group delay at the notched bands is a suitable choice for compact UWB communication systems.