This paper presents a novel method to enhance the pattern characteristics of the TEM horn antenna for 2−19 GHz frequency band. The conventional TEM horn antenna introduces some fluctuations in the main lobe radiation pattern over the center frequencies, which are 10−15 GHz. This motivated us to propose a new method to remove the aforementioned impact by carving an arc shape to the open end of exponentially tapered plates. The associated curvature of this arc is optimized to completely remove the aforementioned fluctuation. The simulation results show that the improved TEM horn antenna structure exhibits low VSWR as well as good radiation pattern over 2−19 GHz frequency band.

https://jpier.org/pier/pier90/08.08123106.pdf

Modified TEM horn antenna for wideband applications

This article presents a wideband millimeter-wave (mmWave) receiver front-end that covers the frequency range from 43 to 97 GHz, supporting the operation in the major parts of the V-, E-, and W-bands. The front-end incorporates a passive mixer-first topology to achieve high linearity and wideband performance. The front-end adopts I/Q generation at the RF port, using a coupled-line coupler (CLC), rather than at the local oscillator (LO) port to mitigate the crosstalk of the overlapping I/Q LO signals especially present at high frequencies. The CLC at the RF input facilitates ultrawide band input matching. The front-end implements the multi-gate gm3 cancellation technique at the IF amplifiers to preserve the linearity and provide gain at the IF section. Image rejection capabilities using a current mode transformer-based IF 90° coupler are implemented on chip and demonstrated with measurements. The front-end prototype is fabricated on the GlobalFoundries 22-nm FD-SOI CMOS process and it demonstrates an ultra-wideband performance across the frequency range 43–97 GHz (2.25:1 bandwidth) with image rejection of up to 32 dB, IIP3 of 1.6–5.2 dBm, and gain of 15 dB. The implementation used is low-IF topology with 3.8-GHz IF frequency and 1-GHz bandwidth. Furthermore, the measurement results show that the front-end supports high-speed modulated signals of up to 6-Gbps 64QAM modulation data.

A 43–97-GHz Mixer-First Front-End With Quadrature Input Matching and On-Chip Image Rejection

A triple-band flexible loop antenna is proposed for WLAN/WiMAX applications in this paper. The proposed antenna is formed by the third-order Hilbert-curve and bending type structure which provides flexible characteristics. Even though the radius of the curvature for bending antennas is changed, a triple-band feature still remains in the proposed antenna. Moreover, the antenna exhibits the characteristics of omnidirectional radiation pattern and circular polarization. To verify the receiving performance of antenna, a simulation on the antenna factor was conducted by an EM simulator. Based on these results, the suggested antenna makes a noteworthy performance over typical loop antennas.

/pdf/flexible-hilbert-curve-loop-antenna-having-a-triple-band-and-24rkvqrpkr.pdf

Flexible Hilbert-Curve Loop Antenna Having a Triple-Band and Omnidirectional Pattern for WLAN/WiMAX Applications

Radar has been used for remote sensing and surveillance for decades Nowadays radar remote sensing and radar surveillance is used for many different things in the modern society Radar can sense objects or environments from very long distance Electromagnetic radar waves can work where and when light cannot This unique ability of radar made remote sensing techniques available in research and in industrial applications Radar can operate in any climate and any time of the day Using ultra-wideband (UWB) pulses for radar in combination with synthesizing apertures, which is so called synthetic aperture radar (SAR), enables radar to produce high resolution images in both range and azimuth directions The work presented in this thesis uses SAR for oil well monitoring SAR is seen as a good candidate to follow oil well changes in time by means of maintenance Other methods to perform this task have been introduced and implemented but they are not able to produce high resolution images from the oil well Using SAR for oil well monitoring provides high resolution images of oil well walls in order to detect the asphaltene or bitumen The resolutions of images can be enhanced by using UWB signal and SAR processing Asphaltene and bitumen are the heavy components of crude oil and capable of blocking the porous media in oil well The porous media is called damaged material when its holes are blocked by asphaltene or bitumen as it cannot pass the oil any more A decrease in oil production is the consequence of this phenomenon If these materials can be detected at very beginning stages of formation, addition of solvent at the location of the detected materials can be very helpful for oil well maintenance This thesis is divided in to two parts The first part focuses on SAR processing whereas the second one aims at antenna design and fabrication to work in a ground penetrating synthetic aperture radar (GPSAR) system In the first part, an oil well model based on the measured electrical properties of common oil well materials is introduced SAR processing is then applied to the oil well model to reconstruct SAR image of the oil well The resulting SAR image is shown to provide high resolutions so that different materials can be distinguished In the second part, a modified TEM horn antenna for SAR is designed, simulated and fabricated The antenna is customized to work in oil media A new profile model for the TEM horn antenna is proposed that modifies the antenna radiation pattern in the design The antenna measurements are shown to be in agreement with the simulated results

/pdf/oil-well-monitoring-by-ultra-wideband-ground-penetrating-q0fzsk88ki.pdf

Oil Well Monitoring by Ultra-wideband Ground Penetrating Synthetic Aperture Radar

Flexible electronics can currently be considered a wellestablished technology that has reached a certain degree of maturity in meeting the requirements of tightly assembled electronic packages, providing reliable electrical connections where the assembly is required to flex during its normal use or where board thickness, weight, or space constraints are driving factors. In this context, flexible substrate antennas (FSAs) play a key role in the integration and packaging of wireless communication devices and sensor networks. Those antennas, which are designed such that the resonant peak frequency remains unaffected after bending, stretching, or twisting, are currently being embedded into materials such as textile fabrics, bandages, stickers, and bendable displays. FSAs are rapidly emerging as a popular choice for radio frequency identification (RFID) tags, multisystem wireless communication gadgets, wearable computer systems, and smart clothing and spurring new applications in wireless sensing such as monitoring of civil construction, health care supervision, or the integration in search and rescue satellite systems. The introduction of new design concepts, new materials and new fabrication processes is adding momentum and interest to the development of flexible antennas for consumer electronics. Researchers are continuingly relying on flexible antenna technology to solve the problems of efficiency, reliability, cost, weight, shape, and reproducibility. There is also the need of using environmentally friendly and lowcost materials and production processes, in order to allow for the easy disposal of a massive number of those devices. This special issue aims at reflecting current research trends and new approaches in FSAs, collecting 13 peer-reviewed articles (with an acceptance ratio of 52%) reporting original research coming from 46 authors of 19 institutions of 14 countries. Authors of this special issue used a variety of materials such as silver nanoparticle ink printed on Kapton polyimide film, ceramic-polymer and carbon-epoxy composites, conductive polymers such as PEDOT or PPy, metamaterialbased artificial magnetic conductor structures, or a copperplated nylon fabric that acts as a conductive electrotextile material. They addressed a number of technologies located in different frequency bands, including near field communications (13,56MHz), UHF RFID tag antennas (860MHz), global navigation satellite systems (L2 band at 1.227GHz and L1 band at 1.575GHz), L-band DVB-H (1452–1492MHz), GSM1800 (1710–1880MHz), PCS1900 (1859–1990MHz), UMTS (1900–2170MHz), wireless local area networks such as WiFi and WiMAX (2.4-, 3.6-, and 5-GHz), Bluetooth (2.4GHz), ultra-wideband (3.1 to 10.6GHz), and even scientific applications at the Ku-band (12–18GHz). This diversity reflects the lively momentum that research of FSAs is experiencing, as corroborated by the number of scientific publications on the topic shown in Figure 1.

https://downloads.hindawi.com/journals/ijap/2012/746360.pdf

Flexible Substrate Antennas

This paper presents a practical and simple broadside coupled-line balun with multi-layers profile microstrip line and broadside coupling structure to enhance the coupled coefficient and balanced output bandwidth Designed broadside coupled-line balun design with a symmetric quarter wavelength coupled-line is developed to increase wider bandwidth efficiency and the return loss is better than the traditional planar marchancd coupled-lines balun The structure of the designed balun is fairly simple, practical and easily fabricated The measured results show good agreements with those analyses data

The Wideband Marchand Balun Transition Design

The design relates generally to the field on antennas and more specifically, to a low profile linear polarized H-shape dipole antenna. The antenna includes a printed circuit board that has a dielectric substrate provided with H-shape face and one dipole element formed on the dielectric substrate. The printed circuit board is also provided with a balance to unbalanced feed network that is operatively connected to the H-shape dipole arm element. In this design, the H-shape dipole antenna fed network with tapered balun is studied. The design and experimental results of low profile microstrip planar dipole antenna with tapered balun shows fairly good performances in this paper. The feed network of the design with wider bandwidth and lower power loss tapered microstrip line to overlap coplanar stripline (CPS) transition that provided unbalanced to balanced line with balanced equal power output of phase. The achieved planar dipole antenna exhibits 421 MHz for VSWR = 2 bandwidths. Full-wave EM analyses shows good agreement with those experimental data.

The Omni-directional Dipole Antenna Structure and Design

A fabricated 1:3 power divider that provides equal power split to all four output ports over a large bandwidth is presented, which can be extended to an arbitrary number of output ports. A new wideband three-way microstrip power divider implemented on a single-layer printed circuit board (PCB) is presented in this design. The proposed three-way planar power divider consists of a branch lines and a combine line for three output ports of characteristics of equal magnitude and in-phase. To demonstrate the design methodology, one prototype is realized. The new design was simulated and validated by the measurement. Measured results show that 10 dB return loss of the three output ports has been achieved across the bandwidth from 1.8 GHz to 10.5 GHz.

The Novel 3-Way Power Dividers/Combiners Structure and Design

The semi-rigid cable for microwave band as a feeding network structure that effectively excited tapered TEM horn antenna geometry is proposed. The semi-rigid cable to parallel waveguide transition then to fed tapered TEM horn antenna. The designed tapered TEM horn antenna has the merits such as wideband, simple feeding network, low profile compact size with fairly good antenna performances such as return loss, peak gain and radiation patterns.

The Tapered TEM Horn Antenna Design for EMC and Radiation Measurement

This paper proposes a new antenna technique for pliant monopole antenna (PMA) as a radiator. This branch meander lines PMA based on two asymmetric meander lines with flexible structure exhibits good performances. Branch lines PMA radiator has the merits to improve antenna bandwidth with fine frequency tuning. The design bandwidth full cover 820 MHz~960 MHz and 1700~1990 MHz The PDA phone for GSM, EGSM, DCS, PCS, CDMA and CDMA2000 applications is well demonstrated with the integration and measurement of the co-designed PMA.

Sen-Yi Huang

Papers

The Wideband Marchand Balun Transition Design

The Omni-directional Dipole Antenna Structure and Design

The Novel 3-Way Power Dividers/Combiners Structure and Design

The Tapered TEM Horn Antenna Design for EMC and Radiation Measurement

The Pliant Monopole Antenna (PMA) Design for Handset Phone Operation