Advantages Of Wide Bandwidth Research Articles

Compact size and wideband 4 × 4 MIMO antenna for 5G NR networks

Abstract In this paper, a crescent-shaped four-port MIMO is proposed to deploy in 5 G wireless network coverage with the advantages of wide bandwidth. The MIMO antenna is printed on an RO4003 substrate (ε r = 3.55) with a thickness of 0.203 mm and a rectangular slot in the ground plane to obtain the desired performance. The antenna is duplicated two times in an orthogonal arrangement to achieve 4 ports MIMO antenna for capacity improvement purposes. The antenna satisfies an impedance bandwidth of 20 GHz (20.5–40.5 GHz) with an isolation of ≥22 dB. Furthermore, the suggested 4-port MIMO antenna is fabricated and tested to validate the simulated outcomes, and good consistency between results is achieved in terms of scattering parameters, radiation patterns, gain, and diversity parameters. The presented 4-port MIMO antenna is considered a good candidate for future 5 G NR networks due to its competitive advantages.

A Broadband Microstrip Antenna with a Strip-Slot Hybrid Structure

In order to solve the problem of narrow bandwidth of traditional microstrip antenna, a broadband patch antenna with Y-shaped microstrip feeder is proposed in this paper, which has the advantage of wider bandwidth and similar radiation pattern characteristics than the traditional microstrip slot antenna. Firstly, the Y-shaped microstrip line is used as the feed based on the straight microstrip line. Secondly, the strip-slot hybrid structure is used based on the square patch. Then the strip-slot hybrid structure is slotted. Finally, the impedance matching is achieved by optimizing the size of the antenna, which greatly widens the impedance bandwidth of the antenna. The full wave simulation software of high frequency structure simulator (HFSS) is used to simulate the proposed antenna structure. The simulation results show that when the reflection coefficient is less than -10dB, the relative bandwidth of the antenna is 22% (4.48-5.60GHz), and the maximum gain of the antenna is 10.72dB.

A low‐profile wideband microstrip patch antenna using double half‐mode resonances

AbstractThis paper presents a miniaturized broadband microstrip patch antenna with a simple geometry. The radiation patch of this antenna comprises two rectangular patches with slightly different sizes, one side of each patch is grounded by metal via‐holes. Two rectangular patches are connected by a microstrip line and fed by a single port. Two rectangular patches produce two closely resonant frequencies achieving broadband performance. This antenna operates on the resonant method of short‐circuiting on one side. Metal via‐holes act as a short‐circuit wall allowing each patch to operate in TM0.5,0 mode. The size of a 1/4 wavelength resonant patch is only half of a conventional microstrip antenna, the overall size of this antenna is almost as same as a conventional rectangular microstrip antenna, making it compact in size. The wideband is achieved by combining two radiating patches, resulting in stable radiation and flat gain. Measurement results show that the antenna has an impedance bandwidth of 4.355.10 GHz (15.8%) using a common dielectric substrate without air layer thickness additionally. The maximum measured realized gain is 4.61 dB. This antenna has advantages of wide bandwidth, low profile, flat gain and ease of manufacturing.

Alternative Approach to Design and Optimization of High-Q Ring Resonators for Membrane-Free Acoustic Sensors.

Membrane-free acoustic sensors based on new principle and structure are becoming a research hotspot, because of many advantages, e.g., their wide bandwidth and high sensitivity. It is proposed that a membrane-free acoustic sensor employs a semi-buried optical waveguide ring resonator (SOWRR) as a sensing element. Using air as the upper cladding medium, the excited evanescent field in the air cladding medium would be modulated by acoustic wave. On this basis, the acoustic sensing model is established. Taking high Q factor and resonance depth as design criteria, the optimal design parameters are given. The optimal values of the air/SiO2: Ge/SiO2 waveguide resonator length and coupling spacing are obtained as 50 mm and 5.6 μm, respectively. The Q factor of the waveguide resonator of this size is as high as 8.33 × 106. The theoretical simulation indicates that the frequency response ranges from 1 Hz to 1.58 MHz and that the minimum detectable sound pressure is 7.48 µPa using a laser with linewidth of 1 kHz. Because of its advantages of wide bandwidth and high sensitivity, the membrane-free sensor is expected to become one of the most promising candidates for the next-generation acoustic sensor.

Integrated photonic RF self-interference cancellation on a silicon platform for full-duplex communication

In-band full-duplex (IBFD) technology can double the spectrum utilization efficiency for wireless communications, and increase the data transmission rate of B5G and 6G networks and satellite communications. RF self-interference is the major challenge for the application of IBFD technology, which must be resolved. Compared with the conventional electronic method, the photonic self-interference cancellation (PSIC) technique has the advantages of wide bandwidth, high amplitude and time delay tuning precision, and immunity to electromagnetic interference. Integrating the PSIC system on chip can effectively reduce the size, weight, and power consumption and meet the application requirement, especially for mobile terminals and small satellite payloads. In this paper, the silicon integrated PSIC chip is presented first and demonstrated for IBFD communication. The integrated PSIC chip comprises function units including phase modulation, time delay and amplitude tuning, sideband filtering, and photodetection, which complete the matching conditions for RF self-interference cancellation. Over the wide frequency range of C, X, Ku, and K bands, from 5 GHz to 25 GHz, a cancellation depth of more than 20 dB is achieved with the narrowest bandwidth of 140 MHz. A maximum bandwidth of 630 MHz is obtained at a center frequency of 10 GHz. The full-duplex communication experiment at Ku-band by using the PSIC chip is carried out. Cancellation depths of 24.9 dB and 26.6 dB are measured for a bandwidth of 100 MHz at central frequencies of 12.4 GHz and 14.2 GHz, respectively, and the signal of interest (SOI) with 16-quadrature amplitude modulation is recovered successfully. The factors affecting the cancellation depth and maximum interference to the SOI ratio are investigated in detail. The performances of the integrated PSIC system including link gain, noise figure, receiving sensitivity, and spurious free dynamic range are characterized.

Design of Novel Ultra-wideband Slow-wave Microstrip Transmission Line

Microwave passive devices with high efficiency, small size, and light weight are one of the fundamental requirements for mobile communication coverage in the 5G frequency band. In this paper, the design of a novel ultra-wideband slow-wave microstrip transmission line is proposed and studied. The electromagnetic field simulation software HFSS is used to simulate the slow-wave microstrip transmission line, and the simulation results show that the ultra-wideband slow-wave structure has the advantage of wider bandwidth, smaller size, and lower cost, which meets the needs of 5G communication systems. Finally, the proposed slow-wave microstrip line is used in the U-shaped phase shifter, and the experimental results show that the novel slow-wave microstrip transmission line has a large application potential in the base station antenna system.

Physical-Layer Network Coding Enhanced Visible Light Communications Using RGB LEDs

Compared with traditional radio frequency (RF)-based techniques, the advantages of wider bandwidth, higher security, and stronger electromagnetic immunity (EMI) capability make visible light communications (VLC) a good candidate technology for the 6th generation (6G) wireless communications. Red, green, and blue (RGB) light-emitting diodes (LEDs) based VLC has become an important research branch due to its low price and high reliability. However, the saturation of photodiode (PD) caused by the ambient background light may seriously degrade the bit error rate (BER) performance of an RGB-VLC system's three spatially uncoupled information streams (i.e., red, green, and blue LEDs can transmit different data packets simultaneously) in practical applications. To mitigate the ambient light interference in point-to-point RGB-VLC systems, we propose, PNC-VLC, a network-coded scheme that uses two LEDs with the same color at the transmitter to transmit two different data streams and we make use of the naturally overlapped signals at the receiver to formulate physical-layer network coding (PNC). The adaptivity of PNC-VLC could effectively improve the BER degradation problem caused by the saturation of PD under the influence of ambient light. We conducted simulations based on the parameters of commercial off-the-shelf (COTS) products to prove the superiority of the PNC-VLC under the influence of four typical illuminants. Simulation results show that the PNC-VLC system can maintain a better and more stable system BER performance under different ambient background light conditions. Remarkably, with 2/3 throughput efficiency, PNC-VLC can bring 133.3% gain to the BER performance when compared with the traditional RGB-VLC systems under the Illuminant A interference model, making it a good option for VLC with unpredictable ambient background interferences.

Multifunctional Two-Terminal Optoelectronic Synapse Based on Zinc Oxide/Poly(3-hexylthiophene) Heterojunction for Neuromorphic Computing

With the advantages of wide bandwidth, low power consumption, high propagation speed, and excellent interconnectivity, the light-tunable synapse is regarded as one of the most promising candidates to pave the way for constructing neuromorphic computing and overcoming the von Neumann bottleneck. Herein, an optoelectronic synaptic memristor based on zinc oxide/poly(3-hexylthiophene) (ZnO/P3HT) heterojunction is fabricated via a simple two-step spin coating process. The prepared device can simulate typical neuromorphic manners, such as excitatory postsynaptic current (EPSC), paired-pulse facilitation (PPF), the transformation from short-term plasticity (STP) to long-term plasticity (LTP), and “learning-experience” behavior by modulating the applied light pulses. In addition to the optoelectronic synaptic behaviors, our device incorporates light logic functions (“AND” and “OR” operations) and optical information detection and memory functions analogous to those in the human’s visual recognition memory system.

A Self-Packaged Suspended Coplanar Waveguide Leaf-Shaped Wideband Filtenna

In this letter, a multilayer self-packaged suspended coplanar waveguide (SCPW) leaf-shaped wide slot wideband filtenna is proposed by using leaf-shaped feeding source and three-line couplings. The filtenna is designed working at 3.2 GHz with a fractional bandwidth of 52.3% and a gain of 4.02 dBi, and a pair of gain zeros which are used for improving frequency selectivity and suppressing the out-of-band spurious harmonics have been realized because of the introduced filtering circuit. The proposed filtenna has been fabricated and measured, and the experimental results approach to the predictions, while the advantages of wide bandwidth, high gain flatness, high frequency selectivity, and stable radiation pattern have been demonstrated.

Joint communication and radar sensing functions system based on photonics at the W-band

The photonics-based technology has the advantages of wide bandwidth in millimeter wave (mm-wave) communication and radar sensing systems. In the present work, we propose a novel joint communication and radar sensing functions system based on photonics at the W-band. In the proposed system, the broadband linear frequency modulated (LFM) signal and high-speed M-quadrature amplitude modulation (MQAM) signal are simultaneously obtained by heterodyning two free-running external cavity lasers (ECLs). Based on this system, a communication rate of 78 Gbit/s and a radar with a 5-GHz bandwidth is achieved. This is a good solution to incorporate a high-speed communication and high-resolution radar sensing functions system.

A modularized high-power ultra-wideband radiation system based on the space-synthesis method.

In this paper, a high-power ultra-wideband radiation system, composed of multiply radiation modules, is developed based on the space-synthesis method. The radiation module mainly consists of a transistorized pulser, a 2 × 2 combined antenna array, and a power divider. To improve the out parameters [the amplitude, the pulse repetition frequency (PRF), and the rise time] of the transistorized pulser based on the Marx circuit, the influence of the traveling wave process on the output pulse must be concerned. Based on the theoretical analysis, the printed circuit board circuit parameters and the circuit structure of the pulser are optimized. To improve the power synthesis efficiency, the pulse jitter characteristic of the pulser is improved by replacing the conventional base triggering mode with the collector voltage ramp triggering mode for the first-stage avalanche transistor in the pulser. The previous optimized antenna array is utilized in this radiation system, which has a better radiation performance in the prescribed aperture area. In addition, based on the gradient microstrip structure, the power divider integrated with the pulser is designed, which has the advantages of wide bandwidth, low loss, and light weight. Experimental results show that the peak effective potential rEp of the radiation system of 20 radiation modules is 221.8 kV, the maximum PRF could reach 10 kHz, and the half-power radiation angles of its radiation field are about 5° in both the E plane and the H plane. More radiation modules could be integrated into the system to achieve a higher electric field in the future.

A Compact Wideband Filtering Omnidirectional Dipole Antenna Without Extra Circuits

This article presents a design of a compact wideband filtering dipole antenna with an omnidirectional radiation pattern. We analyze the radiation of three kinds of half-wavelength dipoles (strip, U-shaped strip, and folded strip). It is found that these three diploes produce omnidirectional radiation patterns when they work on half-wavelength mode. In the proposed design, we make these three dipoles couple with each other to achieve wide bandwidth. In addition, both electric coupling and magnetic coupling are observed at the lower band and the upper band, respectively. Therefore, two radiation nulls can be achieved without any extra circuit, which makes the proposed antenna filtering property and compact. A prototype is fabricated and measured to verify our idea. The results show that the proposed antenna has a 10 dB bandwidth of 42.51%, an in-band gain of ~2.4 dBi, and an out-of-band radiation suppression of more than 10 dB with a total size of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${0.4}{ {\lambda }}_{{0}}\,\,{\times }\,\, 0.06{ {\lambda }}_{{0}}$ </tex-math></inline-formula> . The above advantages of wide bandwidth, filtering property, small size, and easy fabrication make the proposed antenna have potential applications on various wireless communication systems.

A Broadband Circular Waveguide Rotary Joint With Substrate Integrated Coaxial Line Feeder

This paper proposed a broadband circular waveguide rotary joint with substrate integrated coaxial line (SICL) feeder. The SICL feeder can effectively convert TEM mode in the SICL into TM210 and TM020 modes in the multi-mode substrate integrated circular cavity (SICC). The annular slot on the surface of SICC can provide strong coupling between the SICC with TM210 and TM020 modes and the circular waveguide cavity with TM010 and TM011 modes. All the modes show symmetric electric field distribution. Thus, a wide bandwidth can be obtained due to six modes and strong coupling, and stable performance can be achieved while rotating because of symmetric field distribution. Comparing with reported circular waveguide rotary joints, the proposed design has the advantages of wide bandwidth and planarization of feeder. A prototype centered at 9.35 GHz is fabricated with a 10-dB impedance matching bandwidth of 24.6% and the insertion loss is between 0.82 dB to1.65 dB.

Microwave frequency measurement with high accuracy and wide bandwidth based on whispering-gallery mode barcode.

We propose and experimentally demonstrate a novel method for photonic-assisted microwave frequency measurement based on whispering-gallery mode (WGM) barcode, which is a dense spectrum generated by a micro-resonator that supports a large number of optical modes. The measurement relies on the relation between the microwave frequency and its unique barcode. The proposed system has the advantages of wide bandwidth, high accuracy, and multiple-frequency measurement capability. Microwave frequency measurement from 1 to 20 GHz is experimentally demonstrated with a measurement error of 40 kHz. For multi-tone signals, the frequency resolution is demonstrated to be less than 20 MHz. A dynamic multi-tone microwave signal consists of a 16-20 GHz linear frequency-modulated (LFM) signal, and a 10 GHz signal is measured to show the capability of multiple-frequency measurement. The system stability is also evaluated, and a self-reference method is proposed to maintain a long-term high-accuracy measurement.

A Wideband Compact Magnetoelectric Dipole Antenna Fed by SICL for Millimeter Wave Applications

A wideband compact magnetoelectric (ME) dipole antenna is investigated for millimeter-wave applications. First, an aperture coupled ME dipole is proposed with wideband and low profile. Next, transverse slots are added to miniaturize the antenna. The radiation performance of the higher-order mode is also improved. The antenna is finally miniaturized to 2.5×3.3 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ( 0.27 λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> ×0.35 λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> , where λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> is the wavelength in free space at center frequency) when it is used in the array environment. A bandwidth of 48.8% (24.3-40 GHz) for SWR <; 2 can be achieved, with unidirectional radiation performance over the operating band. By combining the proposed compact antenna with an eight-way substrate integrated coaxial line (SICL) feed network, a 1 ×8 linear array is designed, fabricated, and measured. Good beam scanning capability is also verified by active simulation. With the advantages of wide bandwidth, compact size, promising radiation pattern and wide-angle beam scanning potential, the proposed antenna would be attractive for millimeter-wave devices and antenna in package (AiP) applications.

A Compact Nonsymmetric Wideband Dipole Antenna for Borehole Radar Application

Borehole radar (BHR) is one of the most important types of ground-penetrating radar and has very strict requirements for antenna. Considering the detection resolution and the limited borehole size, the BHR antenna should be both wideband and compact. In this article, a compact nonsymmetric wideband dipole (NSWD) antenna is proposed. One arm of the NSWD antenna consists of several patches with different lengths, and the other one is a hollow metal tube. The combination of patches which are resistively loaded at the ends is used for increasing antenna bandwidth and frequency reconstruction. In addition, a three-section binomial matching transformer is designed for impedances match between antenna ( 120 Ω) and coaxial cable ( 50 Ω). Matching transformer and other radar system devices are housed in the hollow metal tube, which makes the BHR system much compact. The central frequency of the antenna is set to 86 MHz for long-range detection. The proposed antenna is fabricated and measured. The measurement results show that the proposed antenna has the advantages of wide bandwidth (~41.8% from 68 to 104 MHz) and high radiation efficiency (~65%). Finally, the antenna (including electronics) is assembled into a polyvinyl chloride pipe to form a BHR prototype, and we used it to conduct a field test in a water-filled borehole. The experimental results show that the NSWD antenna can work well with the BHR system inside borehole.

Asymmetrically CPW fed square Sierpinski Carpet ultra wideband terahertz antenna

A square shaped Sierpinski Carpet ultra wideband antenna for terahertz applications is proposed in this paper. The proposed antenna contains third iterative radiator asymmetrically fed by a modified feedline and notch loaded coplanar waveguide modified ground plane. The antenna is operating over a frequency spectrum of 2.2–10.5 THz (VSWR≤2). The overall antenna volume is 42 µm × 22 µm × 1.6 µm. It has a peak realized gain of 5.5 dBi along with desirable radiation patterns. The proposed antenna has advantages of wide bandwidth and compact size with respect to previously reported structures.

A Stacked Patch Antenna With Broadband Circular Polarization and Flat Gains

In this paper, a stacked circular polarization (CP) patch antenna with broad impedance bandwidth, axial-ratio (AR) bandwidth, and flat gains is investigated. The antenna is composed of a square ring, double layers’ stacked patches, and four vertical patches. The corner truncated loop served as a sequential phase feeding structure for four driven patches. To improve the impedance matching, four square patches are stacked on the bottom layer. Furthermore, four vertical patches are introduced on the ground plane to broaden the AR bandwidth. Simulated and measured studies are conducted on an antenna prototype to validate the proposed design. The proposed design shows that the measured impedance bandwidth is 4.65–7.21 GHz (43.2%), measured 3-dB AR bandwidth at broadside is 4.9–6.4 GHz (26.5%) and the 1-dB gain bandwidth is 4.75–6.6 GHz (32.6%). Compared with other similar CP stacked patch antennas, the antenna owns advantages of wide bandwidth, compact size, and flat gain.

RF self-interference cancellation by using photonic technology [Invited

Radio frequency (RF) self-interference is a key issue for the application of in-band full-duplex communication in beyond fifth generation and sixth generation communications. Compared with electronic technology, photonic technology has the advantages of wide bandwidth and high tuning precision, exhibiting great potential to realize high interference cancellation depth over broad band. In this paper, a comprehensive overview of photonic enabled RF self-interference cancellation (SIC) is presented. The operation principle of photonic RF SIC is introduced, and the advances in implementing photonic RF SIC according to the realization mechanism of phase reversal are summarized. For further realistic applications, the multipath RF SIC and the integrated photonic RF SIC are also surveyed. Finally, the challenges and opportunities of photonic RF SIC technology are discussed.

A Wideband Dual-Polarized Antenna for Millimeter-Wave Applications

A wideband dual-polarized magneto-electric (ME) dipole for millimeter waveband applications is presented. The ME dipole consists of four shorted patches, which are fed by two pairs of T-shaped probes orthogonally oriented on the same layer. The feed lines are connected with the T-shaped probes through metallic vias. Simulated overlapped impedance bandwidth of 50% with return loss larger than 10 dB, gain up to 9.4 dBi, and isolation higher than 17.8 dB between dual polarizations are achieved. By combining the antenna elements with single-layered feed networks, a 2 ×2 array is designed, fabricated, and measured. The overlapped working bandwidth is 50%, with gain up 14.8 dBi. With the advantages of wide bandwidth, single-layered radiation structure, and promising radiation pattern, the proposed antenna with dual polarizations would be attractive for millimeter-wave antenna in package (AiP) applications.