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Showing papers on "Coplanar waveguide published in 2011"


Journal ArticleDOI
TL;DR: In this article, the authors study the dependence of superconducting coplanar waveguide (SCPW) resonators performance on materials and geometry as a function of temperature and excitation power.
Abstract: Superconducting coplanar waveguide (SCPW) resonators have a wide range of applications due to the combination of their planar geometry and high quality factors relative to normal metals. However, their performance is sensitive to both the details of their geometry and the materials and processes that are used in their fabrication. In this paper, we study the dependence of SCPW resonator performance on materials and geometry as a function of temperature and excitation power. We measure quality factors greater than 2 × 106 at high excitation power and 6 × 105 at a power comparable to that generated by a single microwave photon circulating in the resonator. We examine the limits to the high excitation power performance of the resonators and find it to be consistent with a model of radiation loss. We further observe that while in all cases the quality factors are degraded as the temperature and power are reduced due to dielectric loss, the size of this effect is dependent on resonator materials and geometry. Finally, we demonstrate that the dielectric loss can be controlled in principle using a separate excitation near the resonance frequencies of the resonator.

226 citations


Journal ArticleDOI
TL;DR: In this paper, the authors modeled and simulated the magnitude of the loss from interface surfaces in the resonator and investigated the dependence on power, resonator geometry, and dimensions on superconducting planar resonators.
Abstract: Losses in superconducting planar resonators are presently assumed to predominantly arise from surface-oxide dissipation, due to experimental losses varying with choice of materials. We model and simulate the magnitude of the loss from interface surfaces in the resonator and investigate the dependence on power, resonator geometry, and dimensions. Surprisingly, the dominant surface loss is found to arise from the metal-substrate and substrate-air interfaces. This result will be useful in guiding device optimization, even with conventional materials.

200 citations


Journal ArticleDOI
29 Jul 2011-Sensors
TL;DR: It is shown that if the SRRs are placed with the slits aligned with the symmetry plane of the CPW, the structure is transparent to signal propagation, however, if the symmetry is broken, a net axial magnetic field can be induced in the inner region of theSRRs, and signal propagation is inhibited at resonance.
Abstract: The symmetry properties of split ring resonators (SRRs) are exploited for the implementation of novel sensing devices. The proposed structure consists of a coplanar waveguide (CPW) loaded with movable SRRs on the back substrate side. It is shown that if the SRRs are placed with the slits aligned with the symmetry plane of the CPW, the structure is transparent to signal propagation. However, if the symmetry is broken, a net axial magnetic field can be induced in the inner region of the SRRs, and signal propagation is inhibited at resonance. The proposed structures can be useful as alignment sensors, position sensors and angle sensors. This novel sensing principle is validated through experiment.

193 citations


Journal ArticleDOI
TL;DR: In this article, a compact coplanar waveguide (CPW)-fed zeroth-order resonant (ZOR) antennas are designed on a CPW single layer where vias are not required.
Abstract: This paper presents the design and analysis of compact coplanar waveguide (CPW)-fed zeroth-order resonant (ZOR) antennas. They are designed on a CPW single layer where vias are not required. The ZOR phenomenon is employed to reduce the antenna size. The novel composite right/left-handed (CRLH) unit cell on a vialess single layer simplifies the fabrication process. In addition, the CPW geometry provides high design freedom, so that bandwidth-extended ZOR antennas can be designed. The antenna's bandwidth is characterized by the circuit parameters. Based on the proposed bandwidth extension technique, symmetric, asymmetric, and chip-loaded antennas are designed. The ZOR characteristic and bandwidth extension are verified by a commercial EM simulator. Their performances are compared with those of previously reported metamaterial resonant antennas. They provide further size reduction, higher efficiency, easier manufacturing, and extended bandwidth.

181 citations


Patent
27 Jun 2011
TL;DR: In this paper, the coplanar waveguide (CPW) sections have slots therein in regions thereof connected to the active and passive devices, where the ground plane conductors of the CPW sections have relatively narrow connectable ports.
Abstract: A MMIC having: a substrate; a plurality of active and passive electrical elements disposed on a top surface of the substrate; a plurality of coplanar waveguide transmission line sections disposed on the top surface of the substrate for electrically interconnecting the active and passive electrical elements; an electrical conductor disposed on a bottom surface of the substrate under the coplanar waveguide section. Edges of ground plane conductors of the coplanar waveguide (CPW) sections have slots therein in regions thereof connected to the active and passive devices. The design of such circuit includes mathematical models of the CPW with the pair of local ground planes and the strip conductor thereof have relatively narrow connectable ports.

147 citations


Journal ArticleDOI
TL;DR: In this paper, a low proflle, compact, wide beam and wide band printed double layered exponentially tapered slot antenna (DTSA) with a coplanar waveguide (CPW) feed meant for wide scan active phased array antenna in X-band has been presented.
Abstract: Design and development of a low proflle, compact, wide beam and wide band printed double layered exponentially tapered slot antenna (DTSA) with a coplanar waveguide (CPW) feed meant for wide scan active phased array antenna in X-band has been presented. DTSA satisfles the requirements on the maximum re∞ection coe-cient of i • i10dB for §60 - and §45 - scan from broadside in H- and E- planes, respectively with a moderate gain of 4{7dBi. Realized antenna has shown a symmetric pattern together with moderately high gain, low cross-polarization and 3dB beam width better than §60 - and §45 - in H- and E- planes, respectively. The designed structure is expected to flnd applications in mounting platforms with limited RF real estate available to it like in military aircrafts, owing to its easy integration with the uni-planar monolithic millimeter-wave integrated circuits.

141 citations


Journal ArticleDOI
TL;DR: A set of external tuning circuits were designed to demonstrate the potential of the proposed configuration for applications where some level of reconfigurability is required and to improve the isolation between the wideband and narrowband ports several modified arrangements were presented and investigated.
Abstract: An integration concept for multi-standard antennas is described. This technique is based on utilizing a relatively large antenna that is printed on the top side of a substrate, acting as a ground for a smaller antenna. The smaller antenna is printed onto the bottom side of the substrate. To validate this concept, an integrated wide-narrowband demonstrator antenna is presented. This antenna is composed of a shorted microstrip patch integrated with a coplanar waveguide (CPW) fed ultrawideband (UWB) antenna. A prototype of the integrated antenna was fabricated and its performance was verified. This arrangement is a promising candidate for applications where some level of reconfigurability is required. For this reason, a set of external tuning circuits were designed to demonstrate the potential of the proposed configuration for such applications. In order to improve the isolation between the wideband and narrowband ports several modified arrangements were presented and investigated.

117 citations


Patent
19 Sep 2011
TL;DR: A dielectric waveguide slot antenna which is capable of radiating a circularly-polarized wave is described in this paper, where the printed circuit board and the conductor plate are joined together with aligning the slot, the via hole and the first through-hole with each other.
Abstract: A dielectric waveguide slot antenna which is capable of radiating a circularly-polarized wave comprises: a dielectric waveguide having a slot through which a dielectric is exposed in a part of an electrically conductive film formed on a surface of the dielectric waveguide; a printed circuit board having a via hole opposed to the slot with the same shape as that of the slot; and a conductor plate having a first through-hole opposed to and having approximately the same shape as the via hole, and a pair of second through-holes in a vicinity of the first through-hole. The dielectric waveguide, the printed circuit board and the conductor plate are joined together with aligning the slot, the via hole and the first through-hole with each other. The printed circuit board has a conductor layer formed in positions facing to the second through-holes, and the second through-holes are arranged point-symmetrically with each other.

116 citations


Journal ArticleDOI
TL;DR: In this paper, a high fMAX InP HEMT transistors in a 5-stage coplanar waveguide integrated circuit were used for low noise amplification at 0.67 GHz.
Abstract: In this letter, low noise amplification at 0.67 THz is demonstrated for the first time. A packaged InP High Electron Mobility Transistor (HEMT) amplifier is reported to achieve a noise figure of 13 dB with an associated gain greater than 7 dB at 670 GHz using a high fMAX InP HEMT transistors in a 5 stage coplanar waveguide integrated circuit. A 10-stage version is also reported to reach a peak gain of 30 dB. These results indicate that InP HEMT integrated circuits can be useful at frequencies approaching a terahertz.

109 citations



Journal ArticleDOI
Yue-Ying Chen1, Yong-Chang Jiao1, Gang Zhao1, Fan Zhang1, Zhen-Lin Liao1, Yu Tian1 
TL;DR: In this article, a dual-band coplanar waveguide (CPW)-fed slot antenna with a C-shaped grounded strip is proposed for dual-sense circularly polarized radiation.
Abstract: A novel dual-band coplanar waveguide (CPW)-fed slot antenna with a C-shaped grounded strip is proposed for dual-sense circularly polarized radiation. The circular polarization in the lower band is achieved by the slots loaded in two opposite corners, and the C-shape grounded strip can offer a current path for the upper band. A rectangular tuning stub protruded into the slot from the signal strip of the CPW is used to obtain good impedance matching over the whole frequency band. Axial-ratio (AR) bandwidth can be significantly enhanced through tuning the horizontal length of the C-shaped grounded strip. The antenna has been investigated numerically and experimentally. Experimental results show that the antenna possesses the measured 10-dB return loss impedance bandwidth of 106.9% (1.01-3.33 GHz). The measured 3-dB AR bandwidths for the lower and upper bands can be up to 32.35% (1.41-1.96 GHz) and 5.6% (2.45-2.59 GHz), respectively.

Journal ArticleDOI
TL;DR: In this paper, a regular hexagonal structure of wide-slot antenna for broadband circular polarization (CP) based on coplanar waveguide (CPW) feed is presented, which protrudes into the slot an L-shape monopole patch, and featuring two inverted-L grounded strips around two opposite sides of the slot.
Abstract: A regular-hexagonal structure of wide-slot antenna for broadband circular polarization (CP) based on coplanar waveguide (CPW) feed is presented. By protruding into the slot an L-shape monopole patch, and featuring two inverted-L grounded strips around two opposite sides of the slot, wide impedance bandwidth and wide axial-ratio (AR) bandwidth can be obtained simultaneously. By notching a rectangle in the ground conductor near the feed line, the antenna performance is further improved. The proposed antenna can provide an impedance bandwidth (S11 <; -10 dB) of 86% and a 3-dB AR bandwidth of 50%, respectively.

Journal ArticleDOI
TL;DR: In this paper, the electromagnetic design and characterization of a micromachined sub-millimeter-wave on-wafer probe is presented, and two designs based on different transmission line topologies are implemented and their performance assessed.
Abstract: The electromagnetic design and characterization of a micromachined submillimeter-wave on-wafer probe is presented. The mechanical design and fabrication of the probe is presented in the companion paper (Part I). Finite element simulations are applied to design an integrated probe chip to couple between rectangular waveguide and the ground-signal-ground (GSG) probe. Two designs based on different transmission line topologies are implemented and their performance assessed. The insertion loss of the probes over the WR-1.5 band measures between 6-10 dB and return loss measures from 10 to 15 dB. Offset short measurements are used to verify the performance of the probes and that they can be employed for calibrated on-wafer measurements.

Journal ArticleDOI
TL;DR: In this paper, a novel dielectric resonator antenna (DRA) is proposed for ultrawideband (UWB) applications, where a simple rectangular dielectoric resonator is excited by a bevel-shaped patch connected to a coplanar waveguide (CPW) feeding line.
Abstract: A novel dielectric resonator antenna (DRA) is proposed for ultrawideband (UWB) applications, where a simple rectangular dielectric resonator is excited by a bevel-shaped patch connected to a coplanar waveguide (CPW) feeding line. It is found that the bandwidth of the resonant modes can be expanded by using a CPW-fed ground and bevel-shaped patch, and thus a UWB performance can be achieved. Experimental and numerical results were carried out, showing a good agreement. The measured results demonstrate that the proposed DRA achieves an impedance bandwidth more than 3:1, covering the frequency range from 3.1 to 10.6 GHz, which is suitable for UWB applications. Furthermore, to minimise the potential interferences between the UWB system and narrowband systems, such as world interpretability for microwave access and WLAN, UWB DRAs with single band-notched and dual band-notched characteristics were designed, fabricated and measured. The measurement results show good performances in terms of VSWR, antenna gain and radiation pattern. With these features, the proposed antennas are expected to be good candidates in various UWB systems.

Journal ArticleDOI
TL;DR: In this article, the authors investigated vortex induced energy losses in Nb resonators with different spatial distributions of micropatterned pinning sites (antidots) by transmission spectroscopy measurements at 4.2 K.
Abstract: The operation of superconducting coplanar waveguide cavities, as used for circuit quantum electrodynamics and kinetic inductance detectors, in perpendicular magnetic fields normally leads to a reduction in the device performance due to energy dissipating Abrikosov vortices. We experimentally investigate the vortex induced energy losses in such Nb resonators with different spatial distributions of micropatterned pinning sites (antidots) by transmission spectroscopy measurements at 4.2 K. In comparison to resonators without antidots we find a significant reduction in vortex induced losses, and thus increased quality factors over a broad range of frequencies and applied powers in moderate fields.

Journal ArticleDOI
TL;DR: In this paper, a compact dual-polarized dielectric resonator antenna (DRA) fed by a coplanar waveguide (CPW) is presented, which adopts the even and odd modes of a CPW structure, two orthogonal polarizations with good isolation can be excited in the rectangular DRA by a single feeding aperture.
Abstract: A compact dual-polarized dielectric resonator antenna (DRA) fed by a coplanar waveguide (CPW) is presented. By adopting the even and odd modes of a CPW structure, two orthogonal polarizations with good isolation can be excited in the rectangular DRA by a single feeding aperture. The measured 10-dB impedance bandwidths of the two polarizations are 260 (7%) and 440 MHz (11.6%), respectively. Over the operating bandwidth, the measured isolation between two ports is better than 25 dB. A prototype was fabricated and tested. Good agreement between the measured and simulated results is obtained.

Journal ArticleDOI
TL;DR: In this article, a compact ultra-wideband (UWB) bandpass filters with ultra-narrow dual-and quad-notched bands are proposed using the broadside-coupled microstrip/coplanar waveguide (CPW) structure.
Abstract: In this paper, compact ultra-wideband (UWB) bandpass filters with ultra-narrow dual- and quad-notched bands are proposed using the broadside-coupled microstrip/coplanar waveguide (CPW) structure. The multiple-modes UWB operation is obtained through the CPW detached-mode resonator (DMR) and broadside-coupled microstrip/CPW transition. To avoid the existing interferences such as the wireless local-area network signals (i.e., 5.2- and 5.8-GHz bands) in the UWB passband simultaneously, dual-notched bands can be finely employed and independently adjusted by the embedded quarter-wavelength (λ/4) CPW resonators and the λ/4 meander slot-line inserted in the DMR, respectively. To further cancel the interferences from the 3.5-GHz worldwide interoperability for microwave access and 6.8-GHz RF identification communication, the λ/4 meander defected microstrip structure is employed. Based on the structures mentioned above, a series of UWB bandpass filters with dual- and quad-notched bands are then designed and fabricated. With good passband/stopband performances, compact size, and low cost, the proposed filters are attractive for the practical applications.

Journal ArticleDOI
TL;DR: In this paper, a symmetric-aperture antenna for broadband circularly polarized (CP) radiation using a coplanar waveguide (CPW) feed is proposed, which consists of a CPW-feed and a wide symmetric aperture along the diagonal axis.
Abstract: A novel symmetric-aperture antenna is proposed for broadband circularly polarized (CP) radiation using a coplanar waveguide (CPW) feed. The proposed antenna consists of a CPW-feed and a wide symmetric aperture along the diagonal axis. A symmetric-aperture consists of two diamond-shaped sections. The symmetric-aperture and CPW-feeding structure are fabricated on the same plane of a dielectric substrate. Wideband CP radiation is achieved by changing the arms of symmetric-aperture and stripline length. The measured bandwidths of 3-dB axial ratio (AR) and 10-dB return loss are around 68% (2.4-4.85 GHz) and 107% (1.6-5.25 GHz), respectively. The measured boresight gain is more than 3.0 dBic over the CP bandwidth. Overall antenna size is around 0.7λo × 0.7λo × 0.019λo at 3.5 GHz.

Journal ArticleDOI
TL;DR: In this paper, a printed fractal monopole such as the Sierpinski-Carpet (SC) antenna can be considered as a good candidate for comparing a coaxial-fed system with a grounded coplanar waveguides (GCPW)fed antenna.
Abstract: Grounded coplanar waveguides (GCPW) are used to enhance antenna characteristics, namely, reference to the VSWR <; 2 bandwidth and the input impedance dynamic range. A printed fractal monopole such as the Sierpinski-Carpet (SC) antenna can be considered as a good candidate for comparing a coaxial-fed system with a GCPW-fed antenna. Conventional SC can be applied at 6.25-8.4 GHz (ref to VSWR <; 2 ), while modified SC matches throughout the 4.65-10.5 GHz (ref to VSWR <; 2 ). Clearly, this new feeding technique changes the behavior of the fractal elements from multiband to wideband. The GCPW-fed antennas have a low crosspolar field and a well-behaved pattern over the enhanced ones. This system of antennas is a possible competitor for the FCC ultrawideband radio short, fat pipe systems. In addition, time-domain analyses are performed to realize the proposed antenna time-domain application over ultrawideband.

Journal ArticleDOI
TL;DR: In this article, the performance of a low-profile coplanar waveguide (CPW)-fed monopole antenna comprising of a straight strip, a parasitic circular-hat patch, and a slotted CPW ground for broadband operation is presented.
Abstract: The performance of a low-profile coplanar waveguide (CPW)-fed monopole antenna comprising of a straight strip, a parasitic circular-hat patch, and a slotted CPW ground for broadband operation is presented. In this design, use of both the parasitic patch and the embedded ground slots is found an effective skill for intensively exciting dual resonant modes as well as improving the overall impedance bandwidth. The tuning effects of the ground size, the parasitic patch, and the ground slots to the resonance and matching condition were examined, and prototype of the proposed antenna had been constructed and experimentally studied. A measured dual-frequency operation with a broad impedance bandwidth (10 dB return loss) of 77% from 3.4-7.62 GHz, covering the required bandwidths of the lower operating band of the Japan's ultrawideband (UWB), the 3.5/5.5 GHz WiMAX, and the 5.2/5.8 GHz WLAN standards, has finally been explored. Also, a stable monopole-like radiation pattern and an average antenna gain of 4.0 dBi across the operating band have been obtained.

Journal ArticleDOI
TL;DR: In this article, a planar helix with straight-edge connections and incorporating a coplanar waveguide feed has been designed for operation at W-band and has been fabricated using microfabrication technique.
Abstract: A slow-wave structure (SWS) consisting of a planar helix with straight-edge connections and incorporating a coplanar waveguide feed has been designed for operation at W-band and has been fabricated using microfabrication technique. On-wafer cold measurements have been carried out on a number of fabricated SWSs, and the results are reported here for the first time. The parameters measured are return loss, attenuation, and phase velocity, and the results cover a frequency range of 70-100 GHz. Cold-test parameters of the SWS have been also obtained using simulations, and the effects of fabrication, such as surface roughness, have been accounted for by estimating effective conductivity of different parts of the microfabricated structures. The measured and simulated results match well. The effects of silicon wafer resistivity have been also discussed. Planar helical SWSs fabricated in this manner have application in traveling-wave tubes operating at millimeter wave and higher frequencies.

Proceedings ArticleDOI
01 Nov 2011
TL;DR: In this article, a stacked FET, single-stage 45 GHz (Q-band) CMOS power amplifier (PA) is presented, which is implemented in a 45-nm CMOS SOI process.
Abstract: A stacked FET, single-stage 45-GHz (Q-band) CMOS power amplifier (PA) is presented. The design stacked three FETs to avoid breakdown while allowing a high supply voltage. The IC was implemented in a 45-nm CMOS SOI process. The saturated output power exceeds 18 dBm from a 4-V supply. Integrated shielded coplanar waveguide (CPW) transmission lines as well as metal finger capacitors were used for input and output matching. The amplifier occupies an area of 450x500 im² including pads, while achieving a maximum power-added-efficiency (PAE) above 20%.

Journal ArticleDOI
TL;DR: In this article, a wideband antenna with a reconfigurable coplanar waveguide (CPW)-to-slotline transition feed is proposed for pattern diversity applications, where changes between modes are controlled by only two p-I-n diodes.
Abstract: A wideband antenna with a reconfigurable coplanar waveguide (CPW)-to-slotline transition feed is proposed for pattern diversity applications. The feed provides three modes -CPW feed, left slotline (LS) feed and right slotline (RS) feed- without extra matching structures. Changes between modes are controlled by only two p-I-n diodes. Features of the proposed switchable feed include compact size and simple bias circuit. The equivalent transmission line model is used in the analysis of the proposed design. A prototype of the proposed antenna is fabricated, tested, and the obtained results including reflection coefficient, radiation patterns and gains, are present. A measurement of channel capacity is carried out to prove the benefit of pattern diversity when using the proposed antenna in both line-of-sight (LOS) and non-line-of-sight (NLOS) communication scenarios.

Journal ArticleDOI
TL;DR: In this article, a miniaturized circularly polarized (CP) printed square slot antenna (PSSA) fed by a coplanar waveguide (CPW) is proposed.
Abstract: This letter proposes the design of a new miniaturized circularly polarized (CP) printed square slot antenna (PSSA) fed by a coplanar waveguide (CPW). The characteristics of the design are that the CP operation and impedance matching can be independently achieved. The 3-dB axial-ratio band can be excited by protruding into the slot a halberd-shaped metal strip from the signal line of the CPW, whereas the VSWR ≤ 2 impedance band can be produced by implanting in the slot a grounded asymmetric inverted-T strip. Design rules established for the proposed antenna can effectively reduce the sizes of the ground plane and the slot.

Journal ArticleDOI
TL;DR: In this article, the authors present the modeling and measurements of microwave propagation in a coplanar waveguide over graphene in the range of frequencies 40 MHz-110 GHz, which suggest that graphene could work well in a very large bandwidth.
Abstract: We present the modeling and measurements of microwave propagation in a coplanar waveguide over graphene in the range of frequencies 40 MHz-110 GHz, which suggest that graphene could work well in a very large bandwidth. Graphene is acting as a natural matching device because its equivalent resistance at these frequencies is able to vary more than 75% when DC biases are applied in the range −4 V to 4 V on the graphene waveguide.

Journal ArticleDOI
TL;DR: In this paper, a simple compact broadband circularly-polarized square slot antenna (CPSSA) fed by a coplanar waveguide is presented for VSWR < 2.2 GHz.
Abstract: A simple compact broadband circularly-polarised square slot antenna (CPSSA) fed by a coplanar waveguide is presented. A CP bandwidth larger than 38.2% can be attained simply by embedding two inverted-L grounded strips around two opposite corners whereas the impedance bandwidth can be greatly improved through the tuning stubs. The designed CPSSA antenna is 25×25×0.8 mm3, which is 56% smaller than previous CPSSA structures operating over the frequency band between 2.9 and 11.2 GHz for VSWR<2.

Journal ArticleDOI
TL;DR: In this article, a coplanar waveguide (CPW) fed ultra wideband (UWB) antenna with a notch band characteristic is presented for 2.4 GHz and UWB applications.
Abstract: A coplanar waveguide (CPW) fed ultra-wideband (UWB) antenna with a notch band characteristic is presented for 2.4 GHz and UWB applications. The bandwidth is broadened by embedding two inverted L-shaped slots in the CPW ground and the notch band is achieved by etching a rectangle slot in the CPW ground. The notched band can be controlled by adjusting the length of the rectangle slot and the two inverted L-shaped slots. Experimental and numerical results show that the proposed antenna with compact size of 28 × 21 mm 2 , has an impedance bandwidth range from 2.38 GHz to 12.0 GHz for voltage standing-wave ratio (VSWR) less than 2, expect the notch band frequency 5.0–6.0 GHz for HIPERLAN/2, IEEE 802.11a (5.1–5.9 GHz) and C-band (4.4–5 GHz) for satellite and military applications.

Patent
28 Jul 2011
TL;DR: In this paper, a method of forming a superconducting device includes foaming a silicon nitride seed layer on a substrate, and forming a (200)-oriented texture titanium nitride (TiN) layer on the SiN seed layer.
Abstract: Low-loss superconducting devices and methods for fabricating low loss superconducting devices. For example, superconducting devices, such as superconducting resonator devices, are formed with a (200)-oriented texture titanium nitride (TiN) layer to provide high Q, low loss resonator structures particularly suitable for application to radio-frequency (RF) and/or microwave superconducting resonators, such as coplanar waveguide superconducting resonators. In one aspect, a method of forming a superconducting device includes foaming a silicon nitride (SiN) seed layer on a substrate, and forming a (200)-oriented texture titanium nitride (TiN) layer on the SiN seed layer.

Journal ArticleDOI
TL;DR: In this article, a cyclic-olefin copolymer thin film was used as a low-loss thin film for microstrip lines and a grounded coplanar waveguide with a 22 m-thick cyclic co-lope was fabricated and characterised up to 220 GHz.
Abstract: Thin-film microstrip lines and a grounded coplanar waveguide using a cyclic-olefin copolymer as low-loss thin film have been fabricated and characterised up to 220 GHz. Attenuation as low as 0.6 dB/mm around 220 GHz has been measured on a grounded coplanar waveguide with a 22 m-thick cyclic-olefin copolymer thin film.

Journal ArticleDOI
TL;DR: In this paper, a unified design methodology for dual-band and broadband coplanar folded-slot antennas (CFSAs) is presented, which is achieved by using an asymmetric antenna element that is asymmetric with respect to the folded slot, and by adjusting the length of the stub inside the slot.
Abstract: This paper presents a unified design methodology for dual-band and broadband coplanar folded-slot antennas (CFSAs). The design is achieved by using a coplanar waveguide-fed antenna element that is asymmetric with respect to the folded slot, and by adjusting the length of the stub inside the slot. A mathematical derivation, based on a transmission-line model for the asymmetrically-fed coplanar folded-slot antenna, is used on a single-frequency coplanar folded-slot antenna to determine the condition for a second resonance. In this way, when the second resonant frequency is close to the first, broadband uniplanar antennas with ~30%, bandwidth can be designed. In addition, at the dual-band mode, a frequency ratio (f2/f1) of the order of 2.5 or more can be obtained. The effect of the ratio of the feed-shift distance to the length of the stub on the bandwidth is an important parameter, and is shown for both the broadband and dual-band designs. The presented method and tables are simple to use, provide very accurate results, and correctly predict the resonant frequencies for the dual-band coplanar folded-slot antennas. The theoretical and simulated results were verified by measurements of fabricated prototypes. The design guidelines cover a broad range of applications in the 2.4 GHz to 5.25 GHz range, with various bands and bandwidths.