Ultra-wideband Coplanar Waveguide Research Articles

An Ultra-Wideband CPW Fed Slot Antenna for IoT Applications

An Ultra-wideband (UWB) radio is a fast-emerging technology. It is offering several unique attractive features that promotes major advances in wireless communications, networking, imaging, radar and positioning systems. Here, an Ultra-Wideband Coplanar Waveguide fed Monopole antenna for IoT Applications is proposed. The bandwidth of the antenna is enhanced due to the partial rectangular patch and the round corner of the rectangular slot. To validate the simulation results, prototypes of the proposed antenna are fabricated and tested. Based on the results, good agreement has been achieved between the measurement and simulation. The antenna prototype with a total size of 138 mm × 40 mm achieves good impedance matching, constant gain and stable radiation patterns. The impedance bandwidth of the antenna reaches up from 600 MHz to 6.0 GHz for S11 with good omnidirectional radiation performance has also been achieved.

Micromachined Silicon-Core Substrate-Integrated Waveguides at 220–330 GHz

In this article, we present a new technology platform for creating compact and loss-efficient wafer-scale integrated micromachined substrate-integrated waveguides with silicon-core (Si-SIWs) for the 230-330-GHz frequency range. The silicon dielectric core enables highly integrated sub-millimeter-wave systems, since it allows for downscaling the waveguide's cross section by a factor of 11.6, and the volume of components by a factor of 39.3, as compared to an air-filled waveguide. Moreover, geometrical control during fabrication of this type of waveguides is significantly better as compared to micromachined hollow waveguides. The measured waveguide's insertion loss (IL) is 0.43 dB/mm at 330 GHz (0.14 dB/λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">g</sub> , normalized to the guided wavelength). A low-loss ultrawideband coplanar-waveguide (CPW) transition is implemented to enable direct measurements of devices and circuits in this waveguide platform, and this is also the very first CPW-to-SIW transition in this frequency range. The measured IL of the transition is better than 0.5 dB (average 0.43 dB above 250 GHz), which is lower than for previously reported CPW-to-SIW transitions even at 3 times lower frequencies; the return loss is better than 14 dB for 75% of the band. As devices examples implemented in this platform, a filter and H-plane waveguide bends are shown. The waveguides and the devices are manufactured by deep-silicon etching using a cost-efficient two-mask micromachining process.

Miniaturized ultra-wideband coplanarwaveguide lowpass filter with extended stop band

&lt;p class="Default"&gt;In this article, we propose a novel design of large rejected band of miniaturized ultra wide band (UWB) of a planar CPW low pass filter “LPF” based on the use of periodic elements of ‘e’ slots. The goal of this work is to develop a new structure of Low Pass Filter with the following criterion: Miniature, Compact and Easy for Fabrication. The Miniaturization of this structure is achieved by entering the 'e' slot in etching area in the ground of CPW line, to save the standard gap of the adapted coplanar line. The designed coplanar LPF is a compact filter having a large band pass and extended stop band, with the possibility to associate easily with others RF and microwave planar circuits. The entire area of the proposed structure of CPW LPF is 14.3x20 mm&lt;sup&gt;2&lt;/sup&gt;.&lt;/p&gt;

Ultra Wideband Coplanar Waveguide Antenna with an Improved Gain using a Frequency Selective Surfaces (FSS)

In this article, an ultra-wideband FSS reflector has been proposed to enhance the gain of a CPW antenna for UWB applications. A CPW fed antenna having dimensions of 38mm×38mm×1.605mm and FSS unit cell having dimensions 14mm × 14mm × 1.605 mm are presented in the paper. A rectangular slot and stubs are interleaved at the outer edges of the patch for achieving desired characteristics of an ultra-wideband for the frequency range of 3.39 GHz to 12.9 GHz. Simulation results carried out using the CST microwave 2016 version in the time domain are presented for the proposed antenna. An FSS unit cell designed and simulated using periodic boundary conditions and floquet ports is presented. The combined setup of an array of FSS reflector behind the antenna has been simulated in the time domain. This set up shows an improved performance in terms of antenna’s gain. A maximum and minimum gain of 8.14 dB and 4.98 dB has been observed with the presence of FSS reflector behind the coplanar waveguide antenna. A significant improvement of 2.9 dB has been observed over the entire band of antenna’s operation

Ultra-wideband coplanar waveguide-to-asymmetric coplanar stripline transition from DC to 165 GHz

AbstractThis paper presents an ultra-wideband coplanar waveguide (CPW)-to-asymmetric coplanar stripline (ACPS) transition based on aluminum nitride (AlN) substrate. The concepts of designing CPW, ACPS, and CPW-to-ACPS transition are explained. In order to suppress parasitic modes, vias going through AlN substrate are added along the ground traces. The signal trace is tapered out and chamfered to reduce the reflection caused by the termination of ground trace. The CPW-to-ACPS transition is designed, fabricated, and measured in a back-to-back configuration. The fabricated CPW-to-ACPS transition can provide a bandwidth of 165 GHz with an associated insertion loss of 3 dB.

A compact UWB CPW bandpass filter with short‐ended H‐shaped resonator and controllable notched band

AbstractAn ultra‐wideband (UWB) bandpass filter (BPF) using the hybrid microstrip and coplanar waveguide (CPW) structure is proposed in this article.The BPF composes of CPW feed lines and H‐shaped microstrip resonator. By a CPW/microstrip back‐to‐back coupling structure, the UWB BPF was realized with the passband covering the entire UWB band (3.1–10.6 GHz). A narrow notched band achieved by etching slots on the lower impedance part of the H‐shaped resonator to form an open circuit stub. At last, three U‐slot DGSs are used to achieve a good upper‐stopband rejection. The measured results are in good agreement with the simulated results. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1577–1581, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27663

Compact ultra-wideband coplanar waveguide fed fan-shaped antenna with band-notched characteristic

In this article, a compact coplanar waveguide fed fan-shaped monopole antenna for ultra-wideband applications with band-notched characteristic is presented. The antenna with fan-shaped structure occupies a small size of 35 × 30 mm2. An arc-shaped slot locating on the radiating element is used to create the 3.5 GHz band-notch characteristic. And, good radiation patterns and gains within the operating band have been observed. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:62–65, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27224

Design of ultrawideband coplanar waveguide-fed koch-fractal triangular antenna

This article proposes a new ultrawideband coplanar waveguide- fed- triangular antenna operating in the FCC band (3.1–10.6) GHz. This antenna employs Koch fractal to increase the bandwidth of the triangular antenna. Two iterations of this fractal antenna are fabricated and tested and found to have good agreement with numerical simulations obtained using HFSS. Full parametric study of the antenna is provided. © 2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2013.

Novel ultra-wideband coplanar-waveguide bandpass filter with inductance-loaded Y-shaped resonators

A novel ultra-wideband (UWB) coplanar waveguide (CPW) bandpass filter (BPF) with the inductance-loaded Y-shaped resonator has been presented in this letter.The proposed UWB BPF has been constructed by integrating the broadside-coupled microstrip-CPW structures into the inductance-loaded Y-shaped resonator. The broadside-coupled microstrip-CPW structures can get tight coupling for UWB performance. The external quality factor has been analyzed to design the proposed UWB filter. An UWB CPW BPF is designed, simulated, and fabricated to demonstrate the performance of the proposed filter structure. The measured results show good agreement with the simulated ones. The fabricated UWB CPW BPF exhibits excellent performance, including 3-dB insertion loss and 10-dB return loss bandwidths over the entire UWB band with a minimum insertion loss of 0.37 dB at 5.4 GHz, as well as 1-dB insertion loss bandwidth of 3.25–10.2 GHz and group delay variation from 0.18 to 0.28 ns over the frequency range of 3.9–11 GHz. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1134–1137, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25940

Band Notched CPW-FED Hexagonal Fractal Antenna

In this paper, the band notched ultra wide band coplanar waveguide (CPW) fed slot antenna is presented. A rectangular slot antenna is excited by a 50Ω-CPW with a fractal patch. The antenna was studied experimentally regarding impedance bandwidth and radiation patterns. For the proposed antenna, the –10 dB return loss bandwidth could reach 7.45 GHz (3.1 GHz–10.9 GHz), in which a frequency notched band from 4.65 to 6.08 GHz was achieved. The impedance band width for UWB design is about 111% with respect to the centre frequency of 7 GHz. Details of the antenna design, simulated and measured results on the return loss and the E- and H-plane radiation pattern of the proposed antenna are presented. The simulation is performed using the commercially available simulation software Ansoft HFSS.

CPW-fed ultra wideband slot antenna with arc-shaped stub

An ultra wideband coplanar waveguide (CPW) fed slot antenna is presented. A rectangular slot antenna is excited by a 50-CPW with an arc-shaped tuning stub. For the proposed antenna, the −10 dB return loss bandwidth could reach 15.6 GHz (3.7–19.3 GHz), which is about 135% with respect to the centre frequency of 11.5 GHz. Details of the antenna design, simulation and measured results on the return loss and the E-and H-plane radiation patterns of the proposed antenna are presented.

초광대역 평면형 모노폴 안테나를 이용한 능동 안테나 다이플렉서의 설계

본 논문은 초광대역 코프래너 급전 모노폴 안테나를 이용한 능동 안테나 다이플렉서 구조를 제안한다. 제안된 다이플렉서 구조는 초고주파 시스템 집적 패키지 기술(RF System on Package: RF-SoP)을 이용한 것으로서 평면형 초광대역 모노폴 안테나와 능동 소자를 직접 연결법에 의해 연결하여 다이플렉서(diplexer)를 형성하는 방식이다. 이는 안테나 회로 성분과 능동 소자의 패키지 회로 성분으로 형성되는 통과 대역을 이용함으로써 별도로 추가된 대역 통과 필터 등의 회로 구조 없이 다이플렉서를 내장하여 구성하는 방식이다. 따라서 입력된 수신 신호의 주파수 대역에 따라 동작 회로가 분리되며, 분리된 수신 신호가 능동 소자의 동작에 의해 증폭되는 능동 안테나 다이플렉서(diplexer)로서 구성된다. FR-4 에폭시 기판 위에서 제작된 능동 안테나 다이플렉서의 특성을 측정한 결과, 2.4 GHz 수신 단자에서는 0.9 dB의 삽입 손실(insertion loss), 1.1 GHz<TEX>(2.0{\sim}3.1\;GHz)$</TEX> 대역폭, 17.0 dB의 수신 신호 증폭 특성을 보여주었으며, 5.8 GHz 수신 단자에서는 0.8 dB의 삽입 손실, 650 MHz<TEX>$(5.25{\sim}5.9\;GHz)$</TEX> 대역폭, 15.0 dB의 수신 신호 증폭 특성을 보여주었다 또한 -10.0 dB 이상의 주파수 분리(isolation) 특성과 -20.0 dB 이상의 고조파 성분(harmonics) 감쇄 특성을 나타내어, 제시된 능동 안테나 다이플렉서 구조가 설계된 동작을 하고 있음을 알 수 있었다. This paper presents active antenna diplexers implemented into an ultra-wideband CPW(Coplanar Waveguide) fed monopole antennas. The proposed active antenna diplexer is designed to direct interconnect the output port of a wideband antenna to the input port of two active(HEMT) devices, where the impedance matching conditions of the proposed active integrated antenna are optimized by adjusting CPW(Coplanar Waveguide) feed line to be the length of 1/20 <TEX>$\lambda_0$</TEX>(@5.8 GHz) in planar type wideband antenna. The measured bandwidth of the active integrated antenna shows the range from 2.0 GHz to 3.1 GHz and from 5.25 GHz to 5.9 GHz. The measured peak gains are 17.0 dB at 2.4 GHz and 15.0 dB at 5.5 GHz.

800–5000 MHz ultra-wideband CPW balun

An ultra-wideband coplanar waveguide (CPW) balun for operation over 800–5000 MHz using a commonly used hybrid microwave substrate is proposed. The CPW balun consists of a multistage Wilkinson structure, an ‘X’-shaped phase inverting structure, bottom-bridges and via-holes. The proposed balun does not need any additional circuit area for the generation of out-of-phase characteristics, so its size is exactly that of the basis Wilkinson divider.

Ultrawide-band coplanar waveguide-fed rectangular slot antenna

An ultrawide-band coplanar waveguide (CPW) fed slot antenna is presented. A rectangular slot antenna is excited by a 50-/spl Omega/ CPW with a U-shaped tuning stub. The impedance bandwidth, from both measurement and simulation, is about 110% (S11<-10 dB). The antenna radiates bi-directionally. The radiation patterns obtained from simulations are found to be stable across the matching band and experimental verification is provided at the high end of the band.