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In this paper, an RF wire-to-board connector with an ultra-low loss cable is proposed to reduce interconnection loss at mmWave frequencies. A new type of the rotary connector structure with a mating height of 1.4 mm is designed to achieve a bandwidth from DC to 45 GHz. This rotary type RF wire-to-board connector may provide ultra-low loss connection solutions for 5G mobile and base station devices, radar systems, satellite modules, etc. Also, a DSFP high speed connector design is presented, where each of the dual high-speed channels in this connector may operate up to 28 GHz. With a PAM4 modulation technique, the aggregated data rate of the DSFP may reach 224 Gbps to support high-speed transmissions for 5G applications.

This paper presents antenna designs to enhance the performance and electromagnetic susceptibility of the UHF radio frequency identification (RFID) tag on vehicles for Electronic Toll Collections (ETC). By adjusting the radiation pattern of the tag antenna upwards and selecting proper installation environments for tag durability, better performance for the ETC can be achieved. To validate those designs, RFID measurements in the field test site of Telecom Technology Center are performed. The results reveal that the proposed tag antennas may effectively improve the detection rate and read range of the RFID system for the ETC and also reduce electromagnetic interferences from nearby mobile base stations.

A low-profile RF wire-to-board connector design for 5G mobile communications and WiGig applications is presented in this paper. A new connector structure with a mating height of only 0.7mm to achieve a bandwidth from DC up to 70GHz is proposed. This RF connector design may provide jump wire connections in devices for 5G wireless communications and other millimeter wave systems.

A series-fed cavity-back patch array antenna for a miniaturized 77GHz radar module is presented in this paper. Inherently, the microstrip patch antenna has a wider bandwidth with a thicker substrate. However, a ground coplanar waveguide (GCPW) to feed the patch array antenna has less surface wave radiation loss with a thinner substrate. Therefore, a three-layer cavity-back patch array antenna is proposed to fulfil both requirements. Six 10-element series-fed arrays for the 77GHz radar module with the total dimensions of only 36(L) ×18(W)×7(T) mm3 are designed. Good radiation properties in a bandwidth from 77 to 81GHz are obtained.

This paper presents two near field reader antennas for applications in the UHF radio frequency identification (RFID) system. Strong vertical and horizontal magnetic fields in near zones are respectively excited by those two reader antennas, so that the readable distance of the nearfield tags attached on objects can be enhanced significantly. Thus, the reader antennas are capable of near-field identification and positioning applications, such as a casino gaming table. For the gaming management system, many stacked chips with tags embedded can be recognized by using near-field reader antennas so that manpower may be saved to significantly improve counting efficiency.

We reported the progress of developing 400-Gb/s optical transceivers with 1.3-μm electro-absorption modulators for optical interconnect applications in data centers. The key technologies include high-speed light sources, silicon photonics based WDM multiplexers/de-multiplexers, driving and receiving circuits, signal processing and monitoring schemes.

This paper presents ray tracing simulations for wave propagation at millimeter-wave frequencies to be applied in future 5G wireless communications. Since attenuation and blockage of millimeter-wave propagation in urban are much more severe than those at microwave frequencies, the line-of-sight rays and non-line-of-sight reflected rays should be dominant propagation mechanisms. Field distributions will be more constrained and therefore new approaches to improve the coverages of the 5G wireless communications will be needed. The ray tracing method can be applied to evaluate those approaches for improving field coverages in the deployment of the 5G base stations.

This paper presents a pattern reconfigurable antenna operating in the 36∼40 GHz band. It is projected to be used on handheld devices for future 5G wireless communications. The proposed design is a multi-antenna system, which comprises a reconfigurable power divider that excites one or multiple antennas according to system's commands. The diversified antenna excitation combinations provide various radiation patterns to meet the wideband mobile communication need of the future 5G handset. The main challenge is to maintain a proper matching condition under different excitation configurations. In the proposed design, a simple matching circuit is employed to match all cases. A total of fifteen radiation patterns is provided with a four-antenna system.

The popularity of Radio Frequency IDentification (RFID) in realistic applications has produced a variety of interference problems. Typical ones are the existences of metal structures in the neighborhood of reader or tag antennas, which cause strong electromagnetic (EM) scattering fields. To overcome these types of interferences, an antenna subsystem is proposed and developed for the RFID reader antenna applications at 2.45GHz in the near-zone tag detection. The term “near-zone” indicates that the application region can be relatively arbitrary and can be close to the aperture of a phased array antenna. The potential applications can be illustrated by the scenario of indoor product transportation system in the department stores, where the I/O management system is performed at a designated spot (or the detection zone). In this case, the tags on the commercial products will move on the transportation belt through a detection zone.

A combination of the Near Field Communication (NFC) antenna and wireless charging coil for a mobile device is proposed in this paper. By integrating the single dual-mode antenna, the mobile device can provide both the NFC and wireless charging functions. The NFC multi-loop antenna transmits power in a near range by using magnetic field coupling. A capacitive matching circuit is added to achieve good coupling with a nearby NFC device at 13.56 MHz. On the other hand, the wireless charging system harvests energy in also a near range with magnetic field coupling at 100 kHz. A PCB coplanar design is employed to integrate our design into the mobile device. Simulated and measured results are presented and good performance for both NFC and wireless charging is achieved.

This paper presents a novel reconfigurable antenna to be embedded in a handheld device operating in the VHF band from 136 to 174MHz. This device can be applied for an emergency wireless communication system during natural disasters. A reconfigurable structure is included to switch the embedded antenna having a narrow bandwidth to cover the required VHF band with an acceptable radiation efficiency.

In this paper, a low-profile dipole RFID tag antenna with a lateral omni-directional pattern is presented. The proposed low-profile antenna can be easily integrated into a size-limited RFID module. To achieve the lateral omni-directional pattern, two shorting pins are added in this antenna structure, which performs better in stacking environments. Therefore, the proposed antenna is suitable for cold-chain logistics applications.

Due to the growing demand for business-to-customer delivery on perishable goods, a novel business model has been devised to send temperature sensitive goods to the general public without refrigerated trucks. Packages are placed in thermal insulated containers instead, while the temperature is constantly monitored by wireless sensors. Because the cargo space is full of lossy materials, the sensor-integrated antenna is designed to provide radiations in a waveguide-like propagation environment. A low-profile dipole antenna configuration is adopted. Simulation and measurement results demonstrate the proposed conformal antenna can provide the required radiation patterns with decent gains and efficiencies.

A novel low-profile inverted-F film antenna design for in-car DAB Band III (170-240 MHz) applications is presented. This antenna is attached on the front windshield of the car along the edge of the A-pillar, which occupies an area of only 238(L)×27(W)mm2 to reduce sight blockages. Good antenna performance has been obtained.

This summary paper presents a method for evaluating radio frequency identification (RFID) readable ranges, implemented by integrating a spherical scanning antenna measurement system for RFID static tests in an anechoic chamber environment. RFID tags with either forward or reverse links dominated can be evaluated in the 2D and 3D measurement modes of the static test system.

This summary presents an integration of a shielded anechoic chamber environment for the spherical near-field antenna measurement purpose on developing the RFID static test system and provides critical characterization features for evaluating the RFID tag 3D operation performance requirements. The prototype system architecture for the static test system provides the methodology for measuring figures of merit of the tag readable range. This system is capable of performing realistic case measurements for detailed analysis requirements and to provide critical indicators based on the results for optimal RFID tag operation performance over full 3D circumference. The proposed 3D RFID static test system may be applied as an effective tool for optimal tag and reader operation performance developments.

A novel miniature inverted-F antenna for 2.4/5GHz dual-band WLAN applications in a tablet computer is presented. This antenna is composed of three radiating strips and a shorting strip, which occupies an area of 13(L)×6(W)mm2 to be mounted along the side edge of the panel. Good performance for the WLAN applications has been obtained.

A compact inverted-F antenna with multiband operations for LTE, WWAN, WiMAX and WLAN applications is presented. The antenna consists of multi-branch strips and is fabricated on both sides of the ceramic substrate, which has a compact size of 90(L)×10(W)×0.5(T) mm3 to be embedded inside an ultra-thin laptop computer as an internal antenna. Three operating bands covering 673–993 MHz, 1673–3153 MHz and 3316–3603 MHz for the LTE700/2300/2500, WWAN, WiMAX (2.3/2.5/3.5 GHz) and WLAN (2.4 GHz) systems are achieved with good radiation efficiencies.

In this paper, a planar circular patch array antenna that features electric fields focused in the near-field zone for 2.4 GHz radio frequency identification (RFID) applications is presented. This array antenna is implemented by using six circular patch elements and a microstrip feeding network with a proper input phase for each element. The array antenna is capable of enhancing electric field distributions in the near zone to charge and interrogate dipole-like passive tags near the array antenna by capacitive coupling. Readable range is measured for up to 12 tags lined up closely with 1 cm spacing. Applications using the proposed array antenna with an RFID reader by Sunlit are discussed.

Digital television (DTV) broadcasting has drawn worldwide attention in recent years. Many nations will transfer their television broadcast system from analog to digital in the coming future. The frequencies used for DTV broadcasting range from 470 to 860 MHz, a bandwidth of almost an octave. The actual frequency band allocated, however, varies from one nation to the other due to various practical considerations. The USB DTV tuner, inherently a compact and portable receiver, could be the most convenient and cost effective way to receive DTV signals on a notebook or any other multimedia device. While the circuit components and their functionalities could be integrated into a single chip on the printed circuit board, the antenna, whose length is proportional to the wavelength of the operating band, is still large in size and becomes the major bottleneck in developing compact and versatile receivers. Recently, novel antenna designs have been proposed and investigated for DTV applications in literatures [1]-[3]. While the planar monopole in [1] is large in size, the internal antenna in [2], though compact in size, is prone to damage and cannot be used in mass production. The meander line antenna in [3] is inherently a narrowband design which needs a varactor to adjust its operating frequencies upon applications. To further improve the integration capability of DTV antennas, in this paper we report a novel built-in antenna which can be completely embedded in a USB DTV tuner. The antenna geometry, design methodology, and experimental results will be introduced in the following sections.

In this paper, two UHF reader antennas based respectively on inductive and capacitive couplings for near-field RFID applications are presented. To identify item-level tags with inductive coupling, a loop-type antenna is developed to have strong magnetic fields in near zone. As for the capacitive coupling, a near-field focusing circular patch array fed by a network with various input phases for radiation elements is proposed to enhance the electric field in near zone. Thus, dipole-like tags can be recognized with the capacitive coupling. Measurements show that those antennas operating with commercial readers provide good performance of tag identifications for near-field RFID applications with inductive and capacitive couplings, respectively.

In this paper, an inverted-F antenna with dual-band operations for 2.4/5 GHz WLAN applications in laptop computers is presented. This antenna is composed of a radiating strip, a feed and two meandered shorting strips, which are fabricated on a 0.4 mm thick FR4 substrate and occupy an area of only 3 × 35 mm2. Gain, pattern and efficiency of the antenna are measured in a spherical near-field antenna measurement anechoic chamber. Good performances are obtained. The proposed antenna can be embedded inside the laptop computer for dual-band WLAN systems.

For 2.4 GHz ISM band applications, such as Bluetooth and WLAN communication systems, an antenna effective in both radiation performance and space requirement is a critical part of the portable devices. Antennas used in the portable devices need to be compact, low-cost, efficient, and omni-directional for commercial applications. Thus, a miniature chip antenna without an empty area for 2.4 GHz ISM band applications is proposed in this paper. As shown in Fig. 1, the dimensions of this chip antenna are only 10(L)x3(W)x3.5(H) mm3, fabricated on an FR4 substrate, so that it can be easily installed inside the portable devices. Particularly, the empty area usually needed by using other built-in antennas is not required with our chip antenna. Thus, circuit routing on a multi-layer PCB will not be restricted due to the antenna, and circuit components can even be placed near the antenna. Therefore, the PCB space can be used more efficiently to miniaturize the RF device, and the antenna can be built in the device more flexibly.

In this paper, a new planar miniaturized diplexer is proposed for GSM/DCS dual band cellular phone applications. The design is composed of four sections of a recently proposed planar artificial transmission line (ATL) which is used to replace the conventional series quarter-wavelength transformers and the shunt open-circuited stubs. The experimental results reveal that the proposed diplexer features low insertion loss, high isolation and compact size. At the center frequency of the GSM system, the occupied size of the proposed miniaturized diplexer is merely 24.4 mm times 17.6 mm, or equivalently 0.119 lambdag times 0.086 lambdag . The design methodology, simulated and experimental results are discussed throughout the paper.

This metal mounting tag is basically a dipole-type antenna on a polypropylene (PP) substrate, a low-loss material with epsivr=2 and tandelta=0.006 at 900 MHz, backed with a ground plane. Thus, we have designed a high efficient tag antenna to be mounted on a metal object or any other object. This metal mounting tag antenna has a high gain, light weight, compact size, and low profile very suitable for RFID applications to tag various objects, particularly on metal surfaces.

A planar chip antenna integrated with a low noise amplifier (LNA) for GPS applications at 1.575 GHz is presented in this paper. Software packages, XFDTD and HFSS have been applied to design the chip antenna having dimensions of 10 mm (L) times 8 mm (W) times 0.8 mm (H). An insert molding approach is applied to manufacture the antenna, where meandered metal strips are enclosed with liquid crystal polyester (LCP) to form the chip antenna. Thus, this chip antenna comprises a radiating structure of multiple meandered conducting strips packed with an LCP dielectric composite material to achieve size, performance characteristics and cost effectiveness superior to conventional GPS ceramic patch antennas. The compact surface-mount chip antenna is fully compatible with hand- and reflow- attachment processes. Also, no additional impedance-matching circuit is required so that the occupied length of the antenna built in a GPS receiver operating at 1.575 GHz is just 10 mm.

A miniaturized branch-line coupler based on a newly proposed planar artificial transmission line (ATL) is presented in this paper for UHF RFID applications. This planar artificial transmission line consists of quasi-lumped elements and their discontinuities, and can synthesize microstrip lines with a wide variety of characteristic impedances and electrical lengths. The measurement results agree well with the simulation ones. The experiments demonstrate that the proposed hybrid has a compact size of 24.4 mm times 25.8 mm, or equivalently 0.12lambdag times 0.13lambdag at the operation frequency, 915 MHz. This corresponds to a 73% size reduction as compared to that of a conventional branch-line coupler. The wideband response reveals that the proposed hybrid is well-behaved with no spurious harmonics up to 11.1 GHz.

The key characteristics of the planar UWB chip antenna are summarized in the following: This chip antenna has a low profile, light weight, and compact size. Antenna patterns are omnidirectional, linearly polarized and with high efficiency. The input has 50Omega characteristic impedance and is impedance-matching free with a wide bandwidth. It can be surface-mounted for a compact SMD package. With the LCP insert molding technology, this chip antenna is highly stable with variations in temperature and humidity, and also very cost-effective to have superior performances for applications in the lower commercial band of the UWB system. This chip antenna can be embedded in a variety of portable devices.

A finite difference time domain software package, called XFDTD, is applied to study the characteristics of the base-station sector antennas for mobile communications. The XFDTD simulation software was employed to design several different metal structures for the scattering surfaces, located on the front panels of the base-station antennas. Without varying the appearance and dimensions of the antennas, the scattering surfaces can improve the antenna radiation patterns, such as lowering the level of the back lobe, reducing the field intensity in regions not to be covered, and decreasing the beamwidth of the antenna in the horizontal plane. Thus, cochannel and adjacent-channel interferences can be mitigated and antenna performance may be improved

A planar chip antenna for applications in the 2.4/5.2 GHz dual ISM bands is presented in this summary. A software package, XFDTD has been applied to design the chip antenna having dimensions of 8 mm (L) times 5 mm (W) times 0.6 mm (H). An insert molding approach is applied to manufacture the antenna, where meandered metal strips are enclosed with liquid crystal polyester (LCP) to form the chip antenna. Thus, this chip antenna comprises a radiating structure of multiple meandered conducting strips packed with an LCP dielectric composite material to achieve size, performance characteristics and cost effectiveness superior to other designs. The 8times5times0.6 mm3 compact surface mountable chip antenna is fully compatible with hand- and reflow-attachment processes. Also, no additional impedance-matching circuit is required so that the occupied length of the antenna on PCB is just 8 mm for the 2.4/5.2 GHz ISM band applications

This paper presents a ray-tube tracing method to simulate waves propagating in curved road tunnels from base stations for mobile communications. Ray tubes are traced by including multiple reflections in the curved tunnels and diffractions from wedges of the tunnel structures, together with the direct path. To verify this ray-tube tracing approach, field measurements of 900 MHz signals in two curved road tunnels from GSM base stations were performed for comparisons with the ray-tube tracing simulations. By tracing ray tubes reflected and diffracted from the curved structures of the tunnels, the effects of the curvature on wave propagations in large guiding structures can be evaluated. Good agreement between simulations and measurements has been obtained. A parametric study of the influence of the tunnel geometry and the signal frequency on the path loss is also presented by applying this ray-tube tracing method. Curved tunnels for different radii of curvature in the tunnel cross-section and horizontal plane and also lengths of the curved part are compared, together with rectangular tunnels. Simulations of the field distribution over the cross-section of the curved tunnel away from the transmitting antenna are demonstrated as well. The ray-tube tracing program can be applied to determine the deployment of the base-station antennas for improving signal coverage in tunnels, which may have curved structures

The ray tracing method has been applied successfully to predict wave propagation for wireless communications but it is not computationally efficient. This paper presents a new method, called the global ray-tube tracing method, to trace the global wave tubes instead of many individual rays for simulating GSM signal propagation in urban areas. Therefore, simulation efficiency can be improved significantly so that site-specific signal distributions in cities may be determined more easily and practically. Field measurements on streets in Taipei city were performed, and the results are compared with those obtained from the global ray-tube tracing program. To find the scattering objects, building exterior geometries were extracted from 1:1000 digital city maps. Good agreement between simulations and measurements are obtained.

This paper presents a forward scattering UTD method to evaluate GSM signals along the vertical and transverse planes. Reflections and diffractions in forward directions from the base station to the mobile in those two planes are included to determine the power received by the mobile. To find the scattering objects, building exterior geometries are obtained from 1:1000 digital city maps. An efficient method to identify forward propagation paths of multiple reflections and diffractions is developed. Simulations and measurements of the signals from a GSM base station are compared.

A hybrid approach, combining the ray-tracing method and the periodic moment method (PMM) for material objects, is developed to study the indoor wave propagation, penetrations, and also the scattering due to periodic structures in buildings. The PMM is applied to evaluate the specular and grating transmission and reflection coefficients of the periodic structures. The data are then used in the ray-tracing program to find specular and grating ray tubes for each ray tube illuminating one of the periodic structures. Those excited ray tubes are continuously traced to determine their contributions to receiving antennas. Measurements and simulations for waves propagating inside a staircase are compared and discussed, where the stairs are modeled as singly-periodic wedges having material properties similar to those of the reinforced concrete wall.

To simulate the wave propagation in buildings for wireless indoor communications, one needs to know the reflection and transmission properties of the building structures. Since those properties depend not only on the constitutive parameters of the buildings but also on the thicknesses of the structures, the determination of the constitutive parameters for different building structures is useful in computer simulations for predicting the indoor propagation. A free-space approach is developed to measure the dielectric constants of the walls in buildings. For indoor propagation modeling, the overall effects of the walls are more important, since large areas of the walls will be illuminated by the incoming waves. Other methods such as open-ended coaxial probes measure the local material properties near the contact points of the probes, and local variations of the properties may have significant influences on the measured results. Therefore, the free-space approach is more suitable for determining the material properties of the compound walls for equivalent dielectric constants by modeling the walls as dielectric slabs with uniform thicknesses and material properties.

The electromagnetic (EM) scattering and shielding properties of structures above a lossy half space have been studied by many investigators. Baertlein (1988) introduced a moment method (MM) solution with a surface formulation and the spectral domain Green's function for two-dimensional (2-D) perfect electric conductor (PEC) structures over a lossy half space to study the shielding effectiveness of the PEC plates above the ground. This article presents an MM solution to evaluate the EM shielding properties of three-dimensional (3-D) objects over a lossy half space. The MM with the volume formulation and 3-D Green's functions in the spectral domain is developed, where the 3-D objects can be composed of metallic, dielectric, or magnetic materials.

Simulation methods for predicting wave propagation over irregular terrain in the frequency ranges of VHF, UHF, and microwaves have been studied by many investigators. Those methods were applied to evaluate propagation path losses, coverage predictions, spectrum management, low altitude radar performance, microwave landing systems, etc. UTD ray models with digital terrain data simplified to two-dimensional (2-D) piecewise-linear profiles of wedges have been employed successfully to site-specifically determine terrain wave propagation. This article presents an automated method to simplify raw digital hilly terrain profiles into 2-D straight wedges and trapezoids (two consecutive wedges) based directly on the variations of the terrain elevations along a given vertical Tx-Rx profile. Also, a UTD ray approach for calculating all the forward diffraction from those piecewise-linear 2-D structures is proposed.

A moment method (MM) solution for analyzing the electromagnetic shielding and scattering properties of two-dimensional (2-D) objects over a lossy half space is presented. The objects can be metal, dielectric, or magnetic materials. Also, a lossy half space is included, which may simulate the effects of the earth ground or any flat homogeneous lossy surface. A MM based on a volume formulation and a special Green's function in the spectral domain is developed. Good agreements between the results and those by other methods are obtained.

Summary form only as given. An experimental setup with loop configurations is applied to measure the performance of cable shielding against the magnetic field induction at power frequencies. Such scheme is preferred for shielding measurements in a small test region to avoid the influences of the ground potential rises and the grounding resistances. A quasi-static two-wire transmission line model has been used to simulate and verify the experimental results of the loop circuits. Besides, to test the application of the loop configurations for practical station-to-station routing of the cables, shielding properties obtained from the loop approach are compared with those of the straight parallel circuits determined by using the Electromagnetic Transients Program (EMTP). In addition, methods for improving the shielding of the magnetic field induced voltages excited from power line faults have been investigated by using the EMTP. An approach to correct the geometrical effects of the loop configurations on the measured shielding effectiveness of the cables for the straight parallel circuits is also proposed. Cables with good shielding performance may be designed and tested by using the methods presented in this paper.