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Persistent positive sea surface temperature anomalies (SSTAs) in the mid‐latitude Northeast Pacific (NEP), also known as "warm blob" or "marine heatwave," have substantial ecological and climate effects. This study delves into the spatiotemporal connection between Arctic Oscillation (AO) and SSTAs in the NEP. First, we conduct the lead‐lag correlation and maximum covariance analyses to disentangle the closest temporal relationship between October AO and wintertime SSTAs in the NEP. Then, we categorize the years in positive AO (pAO) phase into two groups: positive AO with warm anomaly (pAO&Blob) group and positive AO without warm anomaly (pAO&noBlob) group based on the October AO index and wintertime blob index. Results show that the positive phase of AO in October strongly influences the wintertime warm SSTAs in the NEP through local and remote pathways. The local pathway is contingent upon the longitudinal positioning of AO‐related high‐pressure anomaly (i.e., anomalous ridge) in the North Pacific. When easterly anomalies prevail at the southern flank of the anomalous ridge over the NEP, they foster warm SSTAs in the NEP. However, different locations of the high‐pressure anomalies may impede the NEP warming. Remote pathways indicate the teleconnections triggered by AO‐related precipitation increase in Greenland and decrease in East Asia, sustaining the high‐pressure anomaly and promoting the anomalous NEP warming. Hence, this study presents new evidence on polar and mid‐latitude climate connections, which may provide potential predictability for the warm SSTAs in the NEP. Plain Language Summary: Under rapid climate change, long‐lasting warm sea surface temperature anomalies (SSTAs) in the mid‐latitude Northeast Pacific (NEP) have attracted wide attention due to their substantial ecological and climate effects. Arctic Oscillation (AO) is the dominant mode of atmospheric circulation variability in mid‐to‐high latitudes of the Northern Hemisphere. Its positive phase is featured by a low‐pressure center in the Arctic region and high‐pressure centers in the mid‐latitude regions. Our results reveal a robust connection between the positive phase of AO in October and warm SSTAs in the NEP during winter. We identify two primary pathways through which the October AO influences the wintertime sea surface temperature (SST) warming in the NEP. Locally, a high‐pressure anomaly over the NEP is associated with easterly wind anomalies to its southern flank, which diminish oceanic latent heat loss to the atmosphere, thus fostering the SST warming in the NEP. However, other locations of the high‐pressure anomaly related to AO may not be favorable for the warming of the NEP. From a remote view, AO can impact the NEP SST through teleconnections due to increased precipitation in Greenland and decreased precipitation in East Asia, sustaining the high‐pressure anomaly over the NEP and further bolstering the NEP warming. Key Points: Temporally, Arctic Oscillation (AO) in October is closely linked to wintertime sea surface temperature (SST) anomalies in the mid‐latitude Northeast Pacific (NEP)The AO‐related anomalous ridge located over the NEP is favorable for the warming of SST locallyRemotely, enhanced rainfall in Greenland and decreased rainfall near East Asia sustain the anomalous ridge over the NEP via teleconnection [ABSTRACT FROM AUTHOR]

A simple process for the design of broadband planar antennas is presented for base station applications. The process is based on a square patch above a ground plane. Only three geometric parameters are involved in the design of a dual-polarized broadband planar antenna, including the width (W s) of the square patch, a trimming angle (θ) of the square, and the height (H) of the patch above the ground plane. By adjusting the critical parameters θ and H , an impedance bandwidth of 50% for return loss (RL) >15 dB is achieved with an isolation of higher than 35 dB. The bandwidth of the broadband planar antenna is enhanced to 67% by etching four Γ slots on the square patch. The operating mechanisms of these broadband antennas are analyzed and verified by simulation and experiment. [ABSTRACT FROM AUTHOR]

This article empirically assessed new opportunities and provides a conceptual justification for promising areas of trade and financial and economic relations between China and Russia amidst ongoing global turbulence, the post-COVID situation, and sanctions pressure. The study utilized the trade gravity model, taking into account the latest trends in the development of the research subject and object, as well as current challenges and trends in the global economy. The study revealed similarities between the political systems, reforms, and policies of China and Russia, with centralized power structures overlapping and supporting each other at international forums such as the UNSC. The findings suggest that both countries plan to increase trade volume in the next two years, with China focusing more on trade and economic development, while Russia works to promote security and political stability. This study provides valuable insights into the economic relationship between Russia and China, its impact on the US and Europe, and highlights the need for effective policy interventions to address the challenges posed by this relationship. It offers significant theoretical and practical contributions, including the potential to unlock the potential of national economies, increase their competitiveness and help states enter a phase of advanced and sustainable development. This article provides several policy recommendations to ensure the long-term sustainability of the economic relationship between Russia and China and foster mutual understanding and trust between their peoples. These include promoting trade diversification, enhancing financial cooperation, addressing trade barriers, strengthening political and security coordination, mitigating negative impacts on other countries, promoting sustainable development, and fostering people-to-people exchanges. [ABSTRACT FROM AUTHOR]

There are two 5G voice solutions, EPS Fallback and VoNR. In the early stage of 5G network construction, 5G base station coverage rate and terminal penetration rate were not high, so EPS Fallback was used as a 5G voice transition solution. At present, with the deployment of 2.6 GHz and 700 MHz networks, the SA network achieves independent networking, and VoNR will be the main solution for 5G voice. In order to actively respond to the deployment of VoNR and analyze the advantages of VoNR from multiple dimensions, an in-depth research on VoNR features, parameters, and application scenarios were conducted, VoNR wireless strategy deployment was formulated, for uplink weak field, interference, large traffic characteristics of all kinds of scenarios functions such as deployment and optimization to provide suggestion and scheme, and prepares for VoNR's official commercial use. [ABSTRACT FROM AUTHOR]

A new low-profile broadband dual-frequency planar antenna is developed for wireless handsets. The dual-frequency antenna consists of a two-strip monopole for the 2-GHz band and a planar monopole for the 5-GHz band. The developed antenna features a low profile due to the introduction of an S-strip and a T-strip which are separately printed on the two sides of a thin substrate (no via process is involved in the fabrication), forming the two-strip monopole. The bandwidth of the dual-frequency planar antenna is enhanced by taking advantage of the two-strip configuration and the mutual coupling between the planar monopole and the two-strip monopole. The dual-frequency planar antenna achieves a bandwidth of ~35% at the 2-GHz band (1.6-2.3 GHz) and ~15% at the 5-GHz band (5.0-5.9 GHz) with an antenna height of 7-8 mm, which may find applications in mobile/wireless communication devices. A theoretical analysis and verifying experimental results are presented. Index Terms--Broadband antenna, dual-frequency antenna, low-profile antenna, monopole, two-strip, wireless applications.

A cavity-backed loop antenna is developed for producing broadband circularly polarized (CP) radiation. The antenna configuration consists of a slot loop and a strip loop. The slot loop radiates a CP wave at a lower frequency while the strip loop produces CP radiation at a higher frequency. A combination of the two frequencies leads to a bandwidth enhancement. The slot/strip loop antenna is fed by a single straight microstrip line. It is demonstrated that the cavity-backed slot/strip loop antenna can achieve an axial ratio ([less than or equal to] 3 dB) bandwidth of 19% with good impedance matching. The antenna configuration is described and the operating principles for broadband circular polarization and impedance matching are analyzed. The antenna performance is confirmed by experimental results. Index Terms--Broadband antenna, cavity-backed antenna, circularly polarized (CP) antenna, loop antenna, slot antenna.

An unbalance-fed cross aperture is developed to excite a short backfire antenna (SBA) for circular polarization. The cross aperture consists of two orthogonal H-shaped slots with a pair of capacitive stubs and is fed by a single probe that forms an unbalanced feed with a shorting pin. It is demonstrated that the cross-aperture-excited SBA can achieve an axial ratio ([less than or equal to] 3 dB) bandwidth of 4.2% with a voltage standing wave ratio (VSWR) bandwidth of 6.5% (VSWR < 1.2) and a gain of 14 dBi. The antenna structure is described and the simulation and experimental results are presented. The mechanisms for impedance matching and circular-polarization production are analyzed. Index Terms--Circularly polarized antenna, short backfire antenna (SBA), slot-fed antenna.

A simple theory is presented to predict the lumped reactance loading for circularly polarized circular loop antennas with a uniform traveling-wave current distribution. The reactive load is located on a circular wire loop of one-wavelength circumference at a position of 45[degrees] away from the feed point. To achieve a uniform traveling-wave current distribution, the loading reactance and the input impedances of the loaded and unloaded loop antennas need to satisfy certain conditions. First, the input resistance and the input reactance of the unloaded loop antenna should have the same absolute value. Second, the input impedance of the loaded loop must be purely resistive and its value needs to be two times of the input resistance of the unloaded loop. Third, the loading reactance should be chosen to be two times in value and opposite in sense of the input reactance of the unloaded loop. These conditions can be approximately met when the circular loop is placed above a ground plane. The loading reactance is determined from the input impedance of the unloaded loop and is optimized for an optimal performance of circular polarization. It is found that the reactive load must be capacitive and its value depends on the height of the loop above the ground plane and the thickness of the wire. The characteristics of the circular polarization and the input impedance of the capacitance-loaded circular loop antennas are investigated. An experimental example is presented to verify the theoretical prediction. Index Terms--Circular loop antenna, circular polarization, reactively loaded antenna, uniform traveling-wave current distribution.

It is demonstrated that the bandwidth of circular polarization (CP) can be significantly increased when one more parasitic loop is added inside the original loop. A single-loop antenna has only one minimum axial ratio (AR) point while the two-loop antenna can create two minimum AR points. An appropriate combination of the two minimum AR points results in a significant enhancement for the CP bandwidth. A comprehensive study of the new type of broad-band circularly polarized antennas is presented. Several loop configurations, including a circular loop, a rhombic loop, and a dual rhombic loop with a series feed and a parallel feed, are investigated. The AR ([less than or equal to] 2 dB) bandwidth of the circular-loop antenna with a parasitic circular loop is found to be 20%, more than three times the AR bandwidth of a single loop. For the rhombic-loop antenna with a parasitic rhombic loop, an AR bandwidth (AR [less than or equal to] 2 dB) of more than 40% can be achieved by changing the rhombus vertex angle. The AR ([less than or equal to] 2 dB) bandwidths of the series-fed and parallel-fed dual rhombic-loop antennas with a parasitic element are 30% and 50%, respectively. A broad-band balun is incorporated into the series-fed dual rhombic-loop antenna for impedance matching. The broad-band CP performance of the loop antennas is verified by experimental results. Index Terms--Broad-band antenna, circularly polarized (CP) antenna, loop antenna.

A new excitation technique is developed to improve the impedance bandwidth and to lower the manufacturing cost of a short backfire antenna (SBA). The new excitation structure consists of a planar monopole and a mierostrip feed line, both of which are printed on the same dielectric substrate. By splitting the printed monopole with a slot, a wide-band performance can be achieved. The new split-monopole-exeited SBA achieves an impedance bandwidth of about 15% [voltage standing wave ratio (VSWR < 2)] while maintaining good radiation performance. As an example, an SBA configuration with the new excitation topology was designed and measured at the 5 GHz UNII band, and good agreement was observed between the simulation and experiment. The effects of the geometric parameters of the excitation structure on the impedance performance are investigated and the operating mechanism of the split-monopole-exeited SBA is discussed. Being a low-cost, high-gain, and wide-band directional antenna, the new SBA can find applications in various wireless systems, such as LMDS, WLAN, and the emerging WiMAX networks. Index Terms--Excitation technique, low-cost antenna, short backfire antenna, wide-band antenna, wireless applications.

The short backfire antenna (SBA) has been widely used for mobile satellite communications, tracking, telemetry, and wireless local-area network applications due to its compact structure and excellent radiation characteristics. The most common excitation topology for the SBA is a balance-fed wire dipole, which has the disadvantage of a narrow frequency bandwidth for the input impedance. In this paper, an H-shaped slot is employed to excite the SBA for the first time. The H-shaped slot is unbalance-fed from a coaxial line. It is demonstrated that the H-shaped slot-excited SBA can achieve a bandwidth for input impedance of more than 20% (VSWR Index Terms--Short backfire antenna, slot-fed antenna, wideband antenna.

The radiation performance of patch antennas on a large-size substrate can be significantly degraded by the diffraction of surface waves at the edge of the substrate. Most of modern techniques for the surface-wave suppression are related to periodic structures, such as photonic bandgap (PBG) or electromagnetic bandgap (EBG) geometries, which require complicated processes and considerable area. The concept of artificially soft surfaces has been proposed to suppress the surface-wave propagation since the 1990s. However, the typical corrugated soft surface only applies to a substrate whose thickness is one quarter guided wavelength. In this paper, a compact soft-surface structure consisting of a square ring of short-circuited metal strips is employed to surround the patch antenna for blocking the surface-wave propagation, thus, alleviating the effect of the edge diffraction and, hence, improving the radiation pattern. Since its operating frequency is determined by the width of the metal strip (about a quarter guided wavelength), the compact soft-surface structure is suitable for a substrate with arbitrary thickness and dielectric constant. More importantly, the compact soft surface can be realized on any via metallization incorporated packaging process, such as liquid crystal polymer (LCP), multilayer organic (MLO), or low temperature cofired ceramic (LTCC) technology. A numerical investigation for a patch antenna surrounded by an ideal compact soft surface is presented and the feasibility of its implementation on LTCC technology is demonstrated. It is shown that the gain at broadside of a patch antenna on a thick and large-size substrate can be increased to near 9 dBi through the use of the proposed compact soft-surface structure. Index Terms--Low temperature cofired ceramic (LTCC) technology, patch antenna, radiation-pattern improvement, soft surface, surface-wave suppression.

The surface-wave diffraction at the edge of a finite-size substrate with a high dielectric constant is the dominant mechanism affecting the radiation pattern of a patch antenna fabricated on this material. A soft-and-hard surface (SHS) can be used to block the surface waves from propagating outward along the dielectric substrate, thus reducing the unwanted diffraction. Patch antennas surrounded by the SHS are analyzed using the finite-difference time-domain (FDTD) technique that implements the SHS boundary conditions using a simple modified subcell model. A square stacked-patch antenna and a circularly polarized (CP) patch antenna on a thick LTCC multilayer substrate are investigated. It is shown that the radiation pattern of the square patch on a big-size substrate can be significantly improved using SHS while the backward radiation level of the CP antenna with SHS on a small-size substrate is considerably reduced. Index Terms--Finite-difference time-domain (FDTD) technique, patch antennas, soft-and-hard surface (SHS).

The length of a wall-shorted rectangular patch antenna can be reduced from ~ [[lambda].sub.0]/4 to ~ [[lambda].sub.0]/8 by a simple folding operation, which results in a stacked shorted-patch (S-P) structure with a resonant frequency that can be controlled by modifying the distance between the stacked (lower and upper) shorted-patches. A theoretical analysis based on a simple transmission-line model is presented and compared with numerical simulations, showing good agreement if the height of the folded patch is much smaller than the patch length. The physical insight of the variation of the resonant frequency for this reduced-size antenna can be understood by considering the antenna as a shorted patch loaded with a capacitor. An experimental verification is carried out for a 15 mm x 15 mm x 6 mm folded S-P antenna prototype designed for the 2.4 GHz ISM band that can achieve a 10-dB return loss bandwidth of 4% and results in a nearly omni-directional radiation pattern. Index Terms--Antenna theory, microstrip antennas, small antennas.

A new numerical technique is presented for calculating the current distributions on wire antennas with a high degree of curvature. The geometry of the wire antenna is expressed by a parametric equation and the current is directly expanded into a series of quadratic B-spline basis functions of the parameter, so that the truncation error in modeling the curved wire structure is avoided. This algorithm is used to analyze a circular loop antenna, a conical equiangular spiral antenna, and a four-arm Archimedian spiral antenna to demonstrate its validity and practical value.