Unbalanced Port Research Articles

Just-in-Time Port Call Optimization: Challenges and IT-Systems

Abstract Many ports serve ships on a first-come-first-serve (FCFS) basis leading to negative environmental impacts due to ships “hurrying up to wait” if berths are not ready forcing them to idle at anchorage. Besides the fuel consumption used at elevated speed to be in good time in the port area, average anchorage times can account for 5 − 10% of ship voyage durations during which ships still emit carbon dioxide (CO2) while running auxiliary engines consuming ca. 15% of the voyage’s marine fuel. Ships deciding to skip or reshuffle port calls due to this might enforce this practice which can result into overall uncertainty, unbalanced port resource utilization including congestion and logjams rippling entire industries. Congested port areas complicate traffic management of arriving and leaving ships. The need to establish a comprehensive system for managing arrivals and departures becomes even more pressing in the case of damaged ships or accidents. Besides, early communicating terminal and port readiness notices allows ships to adjust their speed and save fuel of up to 21% of the overall voyage. Information technological advances made great progress by optimizing individual ship voyages. However, the optimization of cargo transport within a system which can also take into account real-time safety levels of ships, is still unsolved. In this paper, we review past research on just-in-time (JIT) port call optimization (PCO), its challenges, and its way forward through digitalization efforts to achieve desperately needed greenhouse gas (GHG) emissions reductions.

Design of Novel Filtenna for Wireless Applications

In this paper, a novel design based on a dual-mode ring resonator, the filtering balun, feeding the printed dipole antenna, the filter balun antenna (FBA), is presented. One port on the structure allows the signals to be phase-shifted 180 degrees from one unbalanced port to two balanced signals. The suggested designs use a single dual-mode ring resonator to operate as both a filter and a balun at the same time. Compact designs are achieved by applying feeding to the second layer. Another unique characteristic of the filtering balun is its ability to alter, based on perturbation size, the phase error and magnitude imbalance of the two balanced signals. With the use of the Advanced Design System (ADS) software, numerous structures have been developed, modeled, and evaluated. To achieve the highest performance, every section of the design is assessed and optimized. Because the substrate is a lossy type (FR4), the realized transmission coefficients, which are poorer than expected ideal values, make the suggested design a strong contender for narrow-band wireless applications. For S2,1 and S3,1, the signal is routed through two viasand fed into a dipole antenna in the opposite phase by employing the zero iteration for filtering the balun in the first layer to condense with the second layers. The antenna structure is a printed dipole antenna operating at 2.4 GHz

Design of Miniaturized Microwave Filtering-Balun Component for Wireless Applications

This research paper introduces a new design being Minkowski-like fractal filtering-balun MLFFB based on the dual-mode ring resonator. The structure has three ports, converting the signal from one unbalanced port to two balanced ports (i.e., 180° phase shift). The proposed design can act as a filter and balun simultaneously using one dual-mode ring resonator. The fractal curves are applied to have compact designs. The 0th, 1st, and 2nd iterations of the Minkowski-like fractal curves are applied to demonstrate the miniaturization ratio obtained in the proposed work. The miniaturization ratios are 47.8% and 73% of the 1st iteration and 2nd iteration of the Minkowski balun-filtering components, respectively, compared to the 0th iteration. Also, the filtering balun has a distinctive feature, which is the control of the phase error and magnitude imbalance of the two balanced ports, depending on the size of the perturbation part. Several structures have been designed, modeled, and analyzed utilizing the Advanced Design System (ADS) software. Each design iteration is evaluated and optimized to attain the best performance. The operating frequency is 2.4 GHz, and the realized transmission coefficients are S21 = -7 dB and S31 = -6.5 dB, which are less than expected ideal values because the substrate is a lossy type, being FR4. The S11 is less than -10 dB. The proposed design is a good candidate for narrow-band wireless applications.

Large Power Division Ratio Branch-Line Coupler With Differential Through and Differential to Single-Ended Coupling

This article presents a large power division ratio (PDR) branch-line coupler. The proposed coupler can realize the differential signal pass-through from the balanced-to-balanced ports and the single-ended signal coupling from the balanced to unbalanced ports. The authors demonstrate the proposed coupler using a microstrip circuit prototype with a PDR of 10 dB.

A Cavity Balun for High-Power Shortwave Transmission

Compared with conventional systems, high power puts forward more requirements on the balun: the materials and structures should be more reliable, able to withstand high power, and have extremely high transmission efficiency. Based on the electromagnetic field theory and the visual optimization method by CST MW Studio, a parallel-connected coaxial cavity balun is proposed in this article that can realize the balance–unbalance conversion in almost the entire shortwave frequency band (4.4–27 MHz). For further improvement of the transmission efficiency and the reduction of voltage standing wave ratio (VSWR), an antenna tuning unit (ATU) was added to the unbalanced port of the cavity, which lowered the VSWR from 1.5 to 1.1. The theoretical value of the breakdown power of the balun is also calculated, and it is much larger than the transmit power. The results of the scaled mode measurement are consistent with the simulation results: the amplitude imbalance of the balanced port is within ±0.5 dB, the phase difference is 180° ± 5°, and the withstand power is at least three times the transmit power, which fully demonstrates that the proposed balun is suitable for high-power shortwave transmitting systems.

Small Split-Ring Resonators as Efficient Antennas for Remote LoRa IOT Systems-A Path to Reduce Physical Interference.

While wireless IOT modules can be made extremely compact, antennas typically protrude from the module, providing the potential to catch near moving/rotating equipment or transfer loads to the PCB through end forces, which can lead to failures. This work explores the use of split-ring resonator (SRR) designs to achieve a planar antenna with a maximum dimension less than a monopole working at the same frequency. The very narrow bandwidth of the SRR required detailed physical models to create printed circuit board (PCB)-based antenna designs that could be used at LoRa frequencies of 433 MHz and 915 MHz. Uncertainty analysis allowed for the impact of geometrical and physical tolerances on the resonant frequency to be evaluated. Nearfield and farfield measurements were performed allowing for the resonant frequency, directionality, and range of the antenna to be evaluated. An unbalanced SMA port was added to the SRR design to allow for the use of a network vector analyser to determine the input impedance of various designs. The optimum design achieved an input resistance of 44 Ω at a resonant frequency of 919 MHz, close to the target values (50 Ω at 915 MHz). Field measurements of the received signal strength from a planar antenna design indicated a gain of 5 dB over a conventional quarter-wave monopole antenna, in a footprint that was 40% smaller than the monopole.

A novel balanced‐to‐unbalanced branch‐line coupler with large power division ratio

A novel balanced-to-unbalanced branch-line coupler with a large power division ratio (PDR) is proposed in this paper. The proposed coupler consists of six transmission-line sections, which can be easily synthesized with the prescribed PDR. By changing the electrical lengths of two transmission lines, a large PDR range can be obtained without the use of high-impedance transmission lines. The closed-form design equations are provided and discussed. To verify the proposed circuit, a coupler prototype with the PDR of 20 dB and the center frequency of f0 = 1.0 GHz is designed and fabricated. Simulation and measurement results are in good agreement. When the balanced port A is excited, the measured differential-mode to single-ended transmission coefficients at f0 for the unbalanced ports D and C are |SsdDA| = −0.28 dB and |SsdCA| = −20.02 dB, respectively, which meet the desired PDR. The measured |SddAA| at f0 is −33.6 dB with a −10-dB bandwidth of about 12.7% from 0.933 to 1.059 GHz. The |SscDA| and |SscCA| are less than −29.5 dB with a −18-dB bandwidth of 22.4% from 0.924 to 1.157 GHz.

A Wideband Isolated Real-to-Complex Impedance Transforming Uniplanar Microstrip Line Balun for Push–Pull Power Amplifier

In this article, a three-port uniplanar microstrip line balun is proposed to transform the balanced complex load termination to 50- $\Omega $ unbalanced port impedance. The proposed device is designed based on a symmetric four-port network with an open-ended transmission line inserted between branch lines in the middle of structure. To improve the isolation and match the complex termination, a resistive network is proposed and inserted between the two balanced ports. In addition, the theoretical analysis is carried out for the even and odd mode circuits to expand the bandwidth of the proposed real–complex impedance transforming balun. With the proposed design theory, the impedance trajectory follower splitting and combining baluns are designed for wideband push–pull power amplifier (PPPA). To verify the design concept, first, a real–complex impedance transforming uniplanar microstrip line balun is designed and characterized at 1 GHz. Then, a prototype for the wideband PPPA with impedance trajectory follower microstrip baluns is designed, fabricated, and validated in experiment. For the proposed balun, the simulated and measured results agree well with each other to prove the design concept. From the experimental results, the PPPA with the proposed balun shows a gain of 10.2–12.2 dB, output power of 42.7–44.7 dBm, and a drain efficiency of 59.8%–74.6% within the frequency range of 1.8–2.7 GHz.

A Novel Microstrip Line Balun With Transparent Port Impedance and Flexible Open Arm Structure

In this letter, a novel microstrip line balun with transparent port impedance and unconnected flexible output arms is presented. The proposed balun is designed from a symmetric four-port device with an open end at its isolation port. To achieve balun function, a shunt stub is attached between the unbalanced port and the virtual open-ended port to generate a transmission zero under the even-mode circuit. Its odd-mode circuit is treated as an impedance transformer, where the transformer is independent of the terminal impedance. In addition, the proposed balun has flexible open arm branches and does not require a closed loop structure, which provides design flexibility to integrate with other devices compared to conventional closed-loop branch line baluns. The theoretical design equations are derived first to prove the design concept. Then, two prototypes are designed with 35 $\Omega $ system impedance and loaded with 50 and 75 $\Omega $ port impedance, and the measured results match well with the simulation, which further validates the proposed design theory.

A Novel Uniplanar Balun With Transparent Termination Impedance

In this letter, a novel planar branch line balun with transparent port impedance is presented. The balun is designed based on a symmetric four-port network with an open-ended transmission line stub in the middle of the branch at its unbalanced port side. From the even-odd mode analysis, the equivalent network is derived to be a short circuit under even-mode excitation, and the input impedance looking into the unbalanced port satisfies impedance matching under odd-mode excitation. Unlike previous designs, the equivalent cascaded impedance transformer in the proposed structure is independent to the system reference impedance in odd-mode excitation so that the termination at the unbalanced port is transparent to balanced ports. To prove the design concept, the closed-form equations are derived, and multiple prototypes with termination impedances 35, 50, and $75 ~\Omega $ are simulated, fabricated, and characterized.

Wideband balun filter on slot‐line resonator with intrinsic balanced performance in magnitude and phase

In this article, a novel wideband balun filter on the coupled slotline-line resonator topology with intrinsic balanced performance in magnitude and phase performance is presented. The proposed wideband balun filter consists of four uniform half-wavelength slot-line resonators (SLRs) in middle, one single-ended unbalanced port, and one balanced port with two terminals. By utilizing the distinct field conversion from the slotline to the microstrip line feeding line, the proposed technique can realize good balanced performance inherently in magnitude and phase over a wideband frequency range. In order to demonstrate the proposed scheme and support the design conception, one circuit prototype is designed, fabricated, and tested. All of the measured results of the frequency response, magnitude, and phase imbalance performance agree well with the simulated one, and these results have effectively demonstrated its good filtering property, intrinsic balanced performance in magnitude and phase over a wide band frequency.

Balun bandpass filter on slot-line resonators with intrinsic balanced performance in amplitude and phase

AbstractIn this paper, a novel class of balun bandpass filters is presented on slot-line resonator (SLR) toward intrinsic balanced performance in amplitude and phase. The proposed balun filter consists of three inductive-coupled SLRs in the middle, one single-ended unbalanced port, and one balanced port with two terminals. According to the distinct field conversion from the slotline to the microstrip feeding line, good balanced performance in amplitude, and phase performance can be intrinsically realized over a wide frequency range. To validate the proposed technique, a prototype third-order balun filter is designed, fabricated, and measured. Both the simulated and measured results have demonstrated that the proposed balun filter can not only achieve good frequency selectivity but also exhibit intrinsic balanced performance in amplitude and phase.

Design Methodology for Six-Port Equal/Unequal Quadrature and Rat-Race Couplers With Balanced and Unbalanced Ports Terminated by Arbitrary Resistances

For the first time, the 6-port quadrature and rat-race couplers with balanced–unbalanced-hybrid ports are proposed. The corresponding design methodology is presented, which is capable of designing the proposed couplers with arbitrary power divisions and terminated resistances. In this paper, four types including quadrature and rat-race couplers are fully analyzed, covering all the application configurations of the balanced/unbalanced ports. Besides, the design equations are rigorously derived, with the final design procedures presented. Eventually, prototypes of the four coupler types are fabricated and experimentally measured. The final results sufficiently validate the proposed methodology.

A Balanced-to-Unbalanced Hybrid Ring With Arbitrary Power Division Ratio

This paper presents a new balanced-to-unbalanced (BTU) hybrid ring with arbitrary power division ratio. Standard S-parameters and mixed-mode S-parameters are adopted to describe the performance requirements of the BTU hybrid ring. A simple configuration composed of transmission lines is developed to achieve desired functions of the BTU hybrid ring with arbitrary power division ratio. The design equations are given to guide the design. A prototype with the power division ratio of 3:1 is designed to verify the theoretical prediction. The fabricated BTU hybrid ring is matched well for both balanced and unbalanced ports. The BTU power division with arbitrary power division ratio and high mode conversion suppression are also achieved.

Balanced to Unbalanced Power Divider With Arbitrary Power Ratio

In this letter, Balanced to Unbalanced (BTU) Gysel type Power divider (PD) with arbitrary power ratio is proposed. The proposed power divider shows out-of-phase characteristic at two unbalanced ports. Standard $ {4\times 4}$ scattering matrix of BTU PD with arbitrary power ratio is obtained from mixed mode scattering matrix. The analysis of the four port network is done by converting it into a two port network while other ports are matched terminated. Considering realizable impedance range of $ {20-120\;\Omega }$ for microstrip lines, the maximum theoretical power division ratio is 1:4.76. Measurements are performed on a fabricated prototype (power dividing ratio 1:2) to verify the analytical results.

A novel three-dimensional dual-band balun with frequency-independent phase difference and complete ground

A novel three-dimensional (3D) dual-band balun employing the double-sided parallel-strip line (DSPSL) with inherent impedance-transforming capability and complete ground is presented in this paper. The proposed balun is mainly composed of two mutually perpendicular printed circuit boards (PCBs), one of which is a horizontal feeding plane with a slender slot and the other of which is a mounted board vertical to the former.An unbalanced input port and two balanced output ports are totally located at the feeding plane. Utilising the configuration of DSPSL, two different dual-band impedance transformers of two sections are placed in the top and bottom layers of the vertical mounted board respectively. Thus, the transformers are applicable to transform impedances at two frequencies simultaneously. Furthermore, the 180° phase difference is frequency-independent, which facilitates the broadband operation. For verification, two numerical examples with different frequency ratios are designed and simulated, one of ...

Design of microstrip tri‐mode balun bandpass filter with high selectivity

A new microstrip tri-mode balun bandpass filter (BPF) with good filter-type and balun-type functions is presented. To realise the tri-mode BPF performance, the multimode stepped-impedance resonator is introduced and parallel coupled to both the balanced and the unbalanced ports. To achieve 180° phase difference, two types of transition structures, i.e. the microstrip–coplanar waveguide–microstrip transition and the microstrip–coplanar stripline–microstrip transition, are adopted for the two balanced output ports design, respectively. A balun BPF operating at 2.6 GHz is designed and fabricated to validate the feasibility of the new approach. Results indicate that the proposed balun BPF exhibits not only high selectivity with two transmission zeros locating at 1.7 and 3.7 GHz but also good balance performance with 0.5 dB magnitude imbalance and 5° phase imbalance between the balanced outputs.

Wide-Band Planar Balun Based on Simplified Composite Right-Left-Handed Structure

Wide-band planar microstrip balun implemented with simplified composite right/left-handed (SCRLH) structure is presented in this letter. The proposed balun consists of a wide-band Wilkinson power divider and a broadband 180° phase shifter based on SCRLH structure. The new design was simulated and validated by the measurement. In the experimental results, within the frequency range from 3.1 to 8.3 GHz (91.2%), the measured return losses of the unbalanced and balanced ports are greater than 10 dB, and the balanced ports isolation is below 15 dB. The measured amplitude and phase difference between the two balanced ports are within ±0.6 dB and ±50, respectively, over the operating frequency band.

130-nm CMOS $K$-Band Two-Element Differential Power-Combining Oscillators

A power-combining structure at <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">K</i> -band is proposed. The proposed structure, consisted of a multisection of Marchand baluns in series configuration, combines multiple pairs of balanced signals into a single unbalanced port. The active devices, in a differential cross-coupled pair configuration, are then combined with the multibalun structure forming the CMOS multiple element oscillator. The power-combining mechanism is investigated through <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Y</i> - and <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">S</i> -parameters. The power-combination oscillators are implemented in 0.13-μm CMOS technology, demonstrating the ability of monolithic integration. One and two cross-coupled-pair design of oscillator are measured. Experiment results for the oscillators are presented, showing maximum power-combining efficiency of 76.0%.

UNIQUE-PLANAR VIALESS MARCHAND BALUN WITH NOVEL METHOD OF MEASUREMENT

A unique-planar vialess Marchand balun for V-band application is presented. The balun can achieve less than 2 - phase imbalance and 0.3dB amplitude imbalance from 54GHz to 66GHz, with the insertion losses of i3:6dB and i3:9dB for the two balanced ports and the return loss of less than i15dB in the unbalanced port. The novel back-to-back measured method has been proposed and analyzed, the amplitude and phase imbalances can be derived from the measured back-to-back two-port scattering results. The extracted results achieve good agreement with the single balun simulation, with no more than 0.15dB and 1 - amplitude and phase difierences. This balun conflguration and the measurement method can simplify the fabrication, achieve good yield, ease the assembling and decrease the cost.