Single Coaxial Cable Research Articles

A Backing-Layer-Shared Miniature Dual-Frequency Ultrasound Probe for Intravascular Ultrasound Imaging: In Vitro and Ex Vivo Validations.

Intravascular ultrasound (IVUS) imaging has been extensively utilized to visualize atherosclerotic coronary artery diseases and to guide coronary interventions. To receive ultrasound signals within the vessel wall safely and effectively, miniaturized ultrasound transducers that meet the strict size constraints and have a simple manufacturing procedure are highly demanded. In this work, the first known IVUS probe that employs a backing-layer-shared dual-frequency structure and a single coaxial cable is introduced, featuring a small thickness and easy interconnection procedure. The dual-frequency transducer is designed to have center frequencies of 30 MHz and 80 MHz, and both have an aperture size of 0.5 mm × 0.5 mm. The total thickness of the dual-frequency transducer is less than 700 µm. In vitro phantom imaging and ex vivo porcine coronary artery imaging experiments are conducted. The low-frequency transducer achieves spatial resolutions of 40 µm axially and 321 µm laterally, while the high-frequency transducer exhibits axial and lateral resolutions of 17 µm and 247 µm, respectively. A bandpass filter is utilized to separate the ultrasound images. Combining in vitro phantom imaging analysis with ex vivo imaging validation, a comprehensive demonstration of the promising application of the proposed miniature ultrasound probe is established.

Ethernet Over Coaxial (EoC) Cable Telemetry Over High Voltage Dc And High Power Ac For Airborne Sonar Applications


 
 
 We have proposed a new passive component-based coupling scheme to simultaneously transmit high power AC, high voltage DC and high speed data through a long, single core coaxial cable, particularly for Airborne Sonar applications. This method is intended to replace the bulky multicore cables with single core coaxial cables that are compact and effective for transmitting data over long distances. This coupling scheme consists of three couplers to superimpose high power AC, high voltage DC and high speed data at the onboard end of the cable, and three decouplers to separate them at the remote end. The long cable, couplers, decouplers and the acoustic transducer are represented by their corresponding equivalent circuits that are cascaded together to construct the complete network. Power loss in the circuit is minimised by providing impedance matching networks in the form of a T-network transmission line and a tuning coil. The Ethernet over Coaxial (EoC) module can transmit high speed Ethernet data at the rate of 10/100 Mbps for telemetry from onboard to remote units and vice versa. DC voltages up to 300 V are coupled to the single core coaxial cable from the onboard unit and superimposed with high power AC signals and high-speed data. Passive filter-based coupling and decoupling schemes are demonstrated. Network simulation studies and experimental studies are carried out to verify and validate the equivalent circuit model. The transfer functions of each set of couplers and decouplers are determined independently as well as collectively and their effects on the underwater acoustic performance of the system are studied. The model resuls are found to agree with experiments. The proposed system is capable of generating an acoustic Source Level of about 195 dB with the supply of 125 V continuous wave (CW) AC signals, with simultaneous transmission of data at 10 Mbps and DC supply of 260 V from the on-board unit to the remote unit at the end of a coaxial cable of 200 m length. Introduction of impedance matching network is found to increase the source level by about 12 dB.
 
 

Channel Model and Performance Analysis for MIMO Systems with Single Leaky Coaxial Cable in Tunnel Scenarios.

Due to the limited space in the tunnel environment, multiple-input multiple-output (MIMO) systems with double-port fed leaky coaxial cables (LCXs) can not only reduce the number of LCXs, but also improve the channel capacity. Based on the geometry based on single bonce (GBSB) and electromagnetic field radiation theory of LCX, a MIMO channel model with double–port fed LCX in a tunnel scenario is proposed in this paper. The channel impulse response (CIR) is derived, and verified with measurement results in terms of channel capacity. The distribution of channel capacity of single double-port fed LCX under different LCX lengths in the tunnel scenarios has also been analyzed in this work, and the distribution of channel capacity for the LCX–MIMO system with long LCX is predicted. The results show that the single double-port fed LCX–MIMO system outperforms the dipole antenna MIMO system with respect to channel capacity in the considered tunnel scenarios.

Dual-Band Circularly Polarized Antenna Array for 5G Millimeter-Wave Applications

A dual-band miniaturized e-shaped antenna with circular polarization (CP) at 28 and 38 GHz is presented in this work for 5G millimeter-wave applications. Characteristic mode analysis (CMA) is used in the design steps of the antenna. This compact antenna consists of a main radiating patch surrounded by an L-shaped and hat-shaped metallic strips. The design was implemented on a single RO5880 substrate with a thickness of 0.508 mm, and fed by a single coaxial cable. A 2 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times $ </tex-math></inline-formula> 2 antenna array was also developed and validated. The dimensions of this array were <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.5\,\,\lambda _{0}\,\,\times \,\,1.86\,\,\lambda _{0}$ </tex-math></inline-formula> (where <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\lambda _{0}$ </tex-math></inline-formula> is the free space wavelength at 28 GHz). In the lower band of 28 GHz, 95% total efficiency and 12.69 dBiC gain were obtained, while in the higher band of 38 GHz, 90% total efficiency and 11.10 dBiC gain were achieved. The beamforming capability of this dual band array was investigated as well.

Approximation of Propagation Function of Transmission Lines Using Vector Fitting With Aid of a Hybrid Genetic Algorithm and Differential Evolution Algorithm

Vector fitting is a powerful tool for function approximation. However, when it is adopted to approximate the propagation function of transmission lines, the number of poles and corresponding delay times need to be determined beforehand. The conventional determination method is inefficient. In this work, the parameters are determined by a hybrid genetic algorithm and differential evolution algorithm (HybGADE). The proposed approach can result in a better approximation of propagation function, which is proven by a successful implementation to an overhead single core coaxial cable.

Investigation of cable effects in spectral induced polarization imaging at the field scale using multicore and coaxial cables

The spectral induced polarization (SIP) method has emerged as a well-suited laboratory technique to characterize hydrogeologic and biogeochemical parameters in soil samples. However, field applications of the SIP imaging method are still rare, which can be attributed to the particular care required to minimize the contamination of the data by electromagnetic coupling. To date, field procedures rely on the use of two different cables separating the current and potential dipoles to improve the quality of the SIP readings, although this increases the efforts in the field and might reduce the depth of investigation or the spatial resolution of the data. To overcome these limitations, we have investigated the use of a single coaxial cable, as an alternative to improve data quality and simplify field procedures. We evaluate SIP imaging data collected with the same measuring device using a coaxial cable and a combination of multicore cables of different lengths and manufacturers. Data sets collected with a single coaxial cable reveal a significantly lower number of outliers and a high spatial consistency between the phase-lag readings, even for measurements collected with a coaxial cable five times longer than the length of the profile. Furthermore, the data collected with coaxial cables reveal an improved quality for deeper measurements (with a lower signal-to-noise ratio) in comparison to data sets collected with separate cables. Our results demonstrate that the use of coaxial cables might permit the collection of SIP readings with high quality and similar field procedures to those used in resistivity surveys.

Distributed magnetic sensor using reflection coefficients from both ends of single magnetic coaxial cable

The principle of the distributed magnetic sensor by magneto-impedance effect with time domain reflectometry was demonstrated, and the position and strength of the magnetic field were detected simultaneously with a magnetic coaxial cable. This paper presents a distributed magnetic sensor using the forward and reverse reflection coefficients S11 and S22 from both ends of a single magnetic coaxial cable. The method using reflection coefficients includes novel features such as: (1) improvement of the signal-noise ratio for equivalent measurement time and (2) cancellation of the time fluctuation by jitter. It is confirmed that the SNR of a reflected wave with a vector network analyzer is improved by 21.3 dB compared to that of an oscilloscope. Furthermore, the attenuation of a signal wave can be compensated by synthesizing the reflected waves from both ends. As a result, the signal wave is less affected by the attenuation along the length of the cable and is improved by 19.0 dB at the position of 180 mm.

A Hybrid Genetic Algorithm and Vector Fitting Based Approach for Approximation of Propagation Function of Transmission Lines

A hybrid genetic algorithm and vector fitting based approach is proposed for the approximation of the propagation function of transmission lines. In this work, the process of guessing the number of poles and then adjusting corresponding delay times in the conventional method is improved by the genetic algorithm. The proposed approach can result in a better approximation of propagation function, which is proven by a successful implementation to an overhead single core coaxial cable.

Relay based Coupling Scheme of High Speed Communication data, High voltage DC And High Power Pulsed AC for Coaxial Cable

Coaxial cable telemetry is most commonly used in the field of underwater applications like data logging in oil rigs, underwater wireless modem, underwater acoustic measurements, borehole measurements, deep sea telemetry for sediment analysis, airborne sonars, imaging sonars etc. In all the above applications coaxial multicore cables are used. The design and development of relay based coupling scheme which helps to replace the multi core cable with a single core coaxial cable for telemetry application is described. Single core cable is suitable for long distance data communication. Multi core cables are generally heavy and due to the size, may not meet space constraints in complex systems. They are not economical too. The relay based coupling scheme is used to mix or separate the high speed bi-directional communication data, high voltage DC and high power pulsed AC. In single relay scheme one relay is used to switch the centre core of single core coaxial cable. Here the ground is common for both high power AC transmission and high speed bi-directional data path. A dual relay scheme is discussed where two relays are used to switch both the centre core and ground of the single core coaxial cable. This provides more ground isolation and can avoid ground lifting issues while high power AC transmission occurs. The simulation of the coupling scheme was done using PSpice®. A prototype of the coupling scheme was also made for analysis. Filter responses were analysed for each coupling path. The DC coupling filter has 85 Hz cut-off frequency at -3 dB. The cut-off frequency of high speed data coupler is 500 KHz at -3 dB. A 4.3KV peak to peak of 3 KHz and 7 KHz AC signals were transmitted and measurements were taken to analyse the effect of high voltage over different coupling paths. The 3 KHz signal has a peak of 61.88 dB and that of 7 KHz signal, the peak is 62.50 dB. The signal components of 3 KHz signal in the DC path has a voltage level of 9.375 dB and that of 7 KHz signal is 25.63 dB.

TRIPLE-BAND PRINTED DIPOLE ANTENNA FOR RFID/GPS/BLE APPLICATIONS

Progress in wireless communication requires antennas that work on multi-band simultaneously. This paper presents a design method for a multi-band antenna using printed dipole with L-slots fed by a single coaxial cable. Using this method, a triple-band antenna that operates at 868-915 MHz for RFID (radio frequency identification), 1575 MHz for GPS (global positioning system) and 2.45 GHz for BLE (bluetooth low energy) was designed and manufactured. The antenna's parameters for triple-band operation are investigated and discussed. In this antenna design, ANSYS HFSS software using highly accurate finite element method (FEM) simulation is employed to analyze the entire structure. The designed antenna is manufactured using an FR-4 substrate with a dielectric constant (r) of 4.4 and thickness (h) of 1.6 mm. Many prototypes have been fabricated, and good agreement between simulations and measurements has been achieved. The performance of the prototypes has been measured in a standard far-field anechoic chamber. The proposed triple-band antenna is also tested by measuring the reading distance, and it is found that the proposed antenna can be used for RFID applications.

누설전자파 측정을 위한 초광대역 로그주기 안테나의 소형화

In this paper, to implement the electromagnetic wave environment and solve electromagnetic compatibility(EMC) problem, miniaturization of ultra-wide band log periodic dipole antenna for measurement was investigated. In addition, in oder to improve the signal-to-noise ratio in high frequency band, balun was connected to the antenna to stabilize the operation of the differential mode antenna and the single mode coaxial cable. To minimize the total size and to increase bandwidth of the antenna, a fat dipole structure was used for the resonance frequency band below 4 GHz and a general dipole shape was used for that above 4 GHz. The bandwidth of the proposed antenna was represented from 0.6 GHz to 8.0 GHz with a ratio bandwidth of 12.3 : 1. Measured peak gain varies from 5.7 dBi to 9.1 dBi, and a half power beamwidth was presented from 29.4° to 100.2° in operating range.

Scattering of Electric Field from Leaky Coaxial Cable in Confined Area

The new radiation model for the electric field scattering of single leaky coaxial cable (LCX) being a transmitting antenna in the rectangular blind zone at 1.8 GHz is reported. The effect of varying the receiving antenna distance from the LCX on the fluctuation of radiated field using Ray-Tracing Method is examined. The line of sight and reflected paths between the LCX and receiving antenna for both horizontal and vertical polarizations are considered. Furthermore, it is inferred that the selection of appropriate period of slots and distance of the receiver reduce the fluctuations of electric field. The theory and procedures used in this paper can be extrapolated in different slot patterns of the LCX and zones which have many valuable applications for mobile communication in underground mines, tunnels, and railways.

Performance Analysis of MIMO Transmission Scheme Using Single Leaky Coaxial Cable

This letter studies the performance of a multiple-input–multiple-output (MIMO) transmission method using a single leaky coaxial cable (LCX) where two signals are fed at the dual ports of the LCX simultaneously. The performance of this scheme is evaluated in terms of channel matrix rank, channel correlation, and channel capacity. First, a keyhole effect in the slots of LCX is studied analytically, and a closed-form expression of the channel correlation is presented. Then, we concentrate on the influence of the slot period on the correlation, which provides a reference for the LCX design. Finally, both the channel correlation and the channel capacity are simulated by the Monte-Carlo method to verify the theoretical derivation. The results indicate that a 2 × 2 MIMO system using a single LCX has a good performance and also show the relationship between the slot period and the correlation.

Design, Simulation and Comparison of Mixing Schemes for DC, AC and Bidirectional Data through Coaxial Cable

This paper deals with the design and simulation of mixing scheme for remote system operation connected through long coaxial cable. The remote system requires mixing of DC, high power AC and high speed data, which enables a cost effective interconnections through a single coaxial cable. Two schemes are proposed for the mixing, one with a relay based switching, in which the high power AC is in short pulsed form and other with passive filters. Simulation study using Multisim and Matlab was carried out for both the schemes. A comparison of these two schemes is also discussed.

Software interface for high-speed readout of particle detectors based on the CoaXPress communication standard

This article is devoted to the software design and development of a high-speed readout application used for interfacing particle detectors via the CoaXPress communication standard. The CoaXPress provides an asymmetric high-speed serial connection over a single coaxial cable. It uses a widely available 75 Ω BNC standard and can operate in various modes with a data throughput ranging from 1.25 Gbps up to 25 Gbps. Moreover, it supports a low speed uplink with a fixed bit rate of 20.833 Mbps, which can be used to control and upload configuration data to the particle detector. The CoaXPress interface is an upcoming standard in medical imaging, therefore its usage promises long-term compatibility and versatility. This work presents an example of how to develop DAQ system for a pixel detector. For this purpose, a flexible DAQ card was developed using the XILINX Spartan 6 FPGA. The DAQ card is connected to the framegrabber FireBird CXP6 Quad, which is plugged in the PCI Express bus of the standard PC. The data transmission was performed between the FPGA and framegrabber card via the standard coaxial cable in communication mode with a bit rate of 3.125 Gbps. Using the Medipix2 Quad pixel detector, the framerate of 100 fps was achieved. The front-end application makes use of the FireBird framegrabber software development kit and is suitable for data acquisition as well as control of the detector through the registers implemented in the FPGA.

Configuration of MIMO system using single leaky coaxial cable for linear cell environments

Configuration of MIMO system using single leaky coaxial cable for linear cell environments

Accuracy of two-way time transfer via a single coaxial cable

In order to find limits of the accuracy of the two-way time transfer (TWTT) via a single coaxial cable, we have carried out a detailed analysis which is presented in this paper. We applied the TWTT concept when a transmission line is driven by pulse current drivers and the times of arrival of the pulses are measured at the ends of the line. In addition to the estimation of the accuracy, the analysis provides several rules for proper design of a TWTT system with optimal performance. Based on this concept, a TWTT system for highly accurate time distribution or comparison has been designed and realized. For distances up to 1 km the accuracy was better than 100 ps without any additional correction or adjustment. After the influence of the non-symmetry of input–output circuits was corrected, the errors were lower than 20 ps for distances up to 2 km. The TWTT system is designated for keeping unified time in a net of event timers distributed in one building or in a relatively small area. The timing units forming the system guarantee the time transfer parallel to the time tagging of external pulses.

Multimode intravascular RF coil for MRI‐guided interventions

To demonstrate the feasibility of using a single intravascular radiofrequency (RF) probe connected to the external magnetic resonance imaging (MRI) system via a single coaxial cable to perform active tip tracking and catheter visualization and high signal-to-noise ratio (SNR) intravascular imaging. A multimode intravascular RF coil was constructed on a 6F balloon catheter and interfaced to a 1.5T MRI scanner via a decoupling circuit. Bench measurements of coil impedances were followed by imaging experiments in saline and phantoms. The multimode coil behaves as an inductively coupled transmit coil. The forward-looking capability of 6 mm was measured. A greater than 3-fold increase in SNR compared to conventional imaging using optimized external coil was demonstrated. Simultaneous active tip tracking and catheter visualization was demonstrated. It is feasible to perform 1) active tip tracking, 2) catheter visualization, and 3) high SNR imaging using a single multimode intravascular RF coil that is connected to the external system via a single coaxial cable.

Blumlein 펄스파워 전원개발 및 방전특성 평가

This paper discussed the theoretical simulation results for developing the blumlein pulsed power source and showed the circuit configuration and the discharge characteristics of the realistic manufactured pulsed power system. In the simulation, the output voltage characteristics at a load resistor showed the general impulse shape when the impedance of a single coaxial cable is matched with the that of a load resistor. In addition, it is confirmed that output values of the pulsed power can be easily controlled by the duplication of coaxial cables and the pulsed waveform showed the general impulse characteristics.<BR> Specifically, the inception discharge voltage in the gap distance of 5[㎜] between needle and plane electrodes is about 20[㎸] and which is lower than about 29[㎸] in 9[㎜] due to the difference of the reaching time of the inception voltage. Therefore, this paper showed that the output voltage of the blumlein pulsed power source can be easily controlled.

ADVANCED HYBRID SQUID MULTIPLEXER CONCEPT FOR THE NEXT GENERATION OF ASTRONOMICAL INSTRUMENTS

The Superconducting Quantum Interference Device (SQUID) has been used and proposed often to read out low-temperature detectors for astronomical instruments. A multiplexed SQUID readout for currently envisioned astronomical detector arrays, which will have tens of thousands of pixels, is still challenging with the present technology. We present a new, advanced multiplexing concept and its prototype development that will allow for the readout of 1,000–10,000 detectors with only three pairs of wires and a single microwave coaxial cable.