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Wireless communication technology evolves to meet current needs, focusing on antenna size reduction for smaller, multi-frequency devices. This research introduces a novel approach to miniaturizing a multiband Electromagnetic Band Gap (EBG) reflector using a Double Interdigitated Coplanar Waveguide (DICPW) structure. The mushroom-patterned EBG unit cell, employing a double interdigital technique based on a Coplanar Waveguide (CPW), achieves a significantly slower wave on the transmission line. The unit cell size can be reduced from lambda/2 to lambda /8, allowing control over the second to fourth resonance frequencies. Engineered for a fundamental frequency of 1.8 GHz (LTE), the proposed EBG unit cell supports frequency ranges of 2.45 GHz (WLAN), 4.3 GHz (Altimeter), and 5.2 GHz (WLAN). Integrating this EBG reflector with a dipole antenna at the same frequency results in directional radiation patterns and gains of 8.29 dBi, 8.76 dBi, 8.55 dBi, and 8.22 dBi at resonance frequencies. The innovative reflector, with improved gain and compact dimensions, is relevant to cube satellite and wireless communication systems with versatile multiband frequency requirements., QC 20240429

A novel co-designed transition from InP monolithic microwave integrated circuits to silicon micromachined waveguides is presented. The transition couples a microstrip line to a substrate waveguide sitting on top of a vertical waveguide. The silicon part of the transition consists of a top and a bottom chip, fabricated in a very low-loss silicon micromachined waveguide technology using silicon on insulator wafers. The transition has been designed, fabricated and characterized for 220 GHz to 330 GHz in a back-to-back configuration. Measured insertion loss is 3 dB to 6 dB at 250 GHz to 300 GHz , and return loss is in excess of 5 dB., Not duplicacte with DiVA 1485372QC 20231002

A novel co-designed transition from InP monolithic microwave integrated circuits to silicon micromachined waveguides is presented. The transition couples a microstrip line to a substrate waveguide sitting on top of a vertical waveguide. The silicon part of the transition consists of a top and a bottom chip, fabricated in a very low-loss silicon micromachined waveguide technology using silicon on insulator wafers. The transition has been designed, fabricated and characterized for 220 GHz to 330 GHz in a back-to-back configuration. Measured insertion loss is 3 dB to 6 dB at 250 GHz to 300 GHz , and return loss is in excess of 5 dB., Not duplicacte with DiVA 1485372QC 20231002

A novel co-designed transition from InP monolithic microwave integrated circuits to silicon micromachined waveguides is presented. The transition couples a microstrip line to a substrate waveguide sitting on top of a vertical waveguide. The silicon part of the transition consists of a top and a bottom chip, fabricated in a very low-loss silicon micromachined waveguide technology using silicon on insulator wafers. The transition has been designed, fabricated and characterized for 220 GHz to 330 GHz in a back-to-back configuration. Measured insertion loss is 3 dB to 6 dB at 250 GHz to 300 GHz , and return loss is in excess of 5 dB., Not duplicacte with DiVA 1485372QC 20231002

As a proof of principle, operation of traveling-wave resonant-tunneling-diodes (RTDs) oscillators has been demonstrated experimentally in the frequency range 100-400 GHz. A theoretical model describing a realistic coupled system, consisting of a traveling-wave RTD and a patch antenna, has been developed. The model describes the eigen resonances and the eigen modes, which have a mixed character of both subsystems. The model and the experimental results are in agreement with each other. We also demonstrate that some oscillators were switching between different resonant modes of the system with the change of bias. The phenomenon could be used for an extended frequency control of the RTD oscillators.

As a proof of principle, operation of traveling-wave resonant-tunneling-diodes (RTDs) oscillators has been demonstrated experimentally in the frequency range 100-400 GHz. A theoretical model describing a realistic coupled system, consisting of a traveling-wave RTD and a patch antenna, has been developed. The model describes the eigen resonances and the eigen modes, which have a mixed character of both subsystems. The model and the experimental results are in agreement with each other. We also demonstrate that some oscillators were switching between different resonant modes of the system with the change of bias. The phenomenon could be used for an extended frequency control of the RTD oscillators.

A novel co-designed transition from InP monolithic microwave integrated circuits to silicon micromachined waveguides is presented. The transition couples a microstrip line to a substrate waveguide sitting on top of a vertical waveguide. The silicon part of the transition consists of a top and a bottom chip, fabricated in a very low-loss silicon micromachined waveguide technology using silicon on insulator wafers. The transition has been designed, fabricated and characterized for 220 GHz to 330 GHz in a back-to-back configuration. Measured insertion loss is 3 dB to 6 dB at 250 GHz to 300 GHz , and return loss is in excess of 5 dB., Not duplicacte with DiVA 1485372QC 20231002

A novel co-designed transition from InP monolithic microwave integrated circuits to silicon micromachined waveguides is presented. The transition couples a microstrip line to a substrate waveguide sitting on top of a vertical waveguide. The silicon part of the transition consists of a top and a bottom chip, fabricated in a very low-loss silicon micromachined waveguide technology using silicon on insulator wafers. The transition has been designed, fabricated and characterized for 220 GHz to 330 GHz in a back-to-back configuration. Measured insertion loss is 3 dB to 6 dB at 250 GHz to 300 GHz , and return loss is in excess of 5 dB., Not duplicacte with DiVA 1485372QC 20231002

In this article, we present the investigation and design of high-performance transitions from coplanar waveguide (CPW) to single-conductor, corrugated waveguides (WGs), namely, terahertz spoof surface plasmon polariton (SSPP) WGs. In contrast to the previous studies in the literature on CPW-to-SSPP WG transitions, we propose a novel methodology to examine the relationship between the guided wavenumber and momentum matching, which is based on analytical calculations, together with the effects of flaring grounds on transition performance. This novel methodology allows us to design a low-loss transition circuit (TC) for any given CPW and SSPP dimensions, which is demonstrated for the first time in the literature. We verify the proposed methodology by the design, fabrication, and measurement of several TCs. The measurement results show that the insertion losses of the proposed TCs can be as low as -1.2, -1, and -2.4 dB at 0.25, 0.275, and 0.3 THz, respectively, which brings a significant improvement of 0.6-2.3 dB in the 0.25-0.3 THz band, compared with the previously reported studies in the literature for the terahertz band., Scientific and Technological Research Council of Turkey (TUBITAK) [115E219]; Turkish Academy of Sciences Outstanding Young Scientist Award (TUBA GEBIP), This work was supported in part by The Scientific and Technological Research Council of Turkey (TUBITAK) under Grant 115E219 and in part by the Turkish Academy of Sciences Outstanding Young Scientist Award (TUBA GEBIP) 2015.

This paper focuses on the comparison of various advanced substrates such as trap-rich (TR), porous silicon (PSi), gold-doped (Au-Si) and smart-implants PN-junction (DP) in terms of RF performances. Both small- and large-signal measurements were performed, including the study of the influence of temperature and DC bias voltage. The purpose of this paper is to provide an overview, and a more in-depth analysis of DP substrate, of the characteristics of these multiple substrates to facilitate design choices for RF-IC applications.

In this article, we present the investigation and design of high-performance transitions from coplanar waveguide (CPW) to single-conductor, corrugated waveguides (WGs), namely, terahertz spoof surface plasmon polariton (SSPP) WGs. In contrast to the previous studies in the literature on CPW-to-SSPP WG transitions, we propose a novel methodology to examine the relationship between the guided wavenumber and momentum matching, which is based on analytical calculations, together with the effects of flaring grounds on transition performance. This novel methodology allows us to design a low-loss transition circuit (TC) for any given CPW and SSPP dimensions, which is demonstrated for the first time in the literature. We verify the proposed methodology by the design, fabrication, and measurement of several TCs. The measurement results show that the insertion losses of the proposed TCs can be as low as -1.2, -1, and -2.4 dB at 0.25, 0.275, and 0.3 THz, respectively, which brings a significant improvement of 0.6-2.3 dB in the 0.25-0.3 THz band, compared with the previously reported studies in the literature for the terahertz band., Scientific and Technological Research Council of Turkey (TUBITAK) [115E219]; Turkish Academy of Sciences Outstanding Young Scientist Award (TUBA GEBIP), This work was supported in part by The Scientific and Technological Research Council of Turkey (TUBITAK) under Grant 115E219 and in part by the Turkish Academy of Sciences Outstanding Young Scientist Award (TUBA GEBIP) 2015.

This paper investigates a shifting sensing scheme combining slots, transmission lines, and printing technologies. This sensing scheme translates the electrical sensitivity of a transmission line conductor to the insertion phase as a measurement variable. A coplanar waveguide (CPW) based structure was designed, screen-printed, and tested on relative humidity (RH) conditions ranging from 22.8-75.3 %RH. For the first time, a composite material made of poly-pyrrole and TEMPO Oxidized Cellulose Nanofibers (TOCN/PPy) was integrated to the structure and studied as a humidity sensitive conductor in microwave frequencies. The measured sensitivity was 0.154°/%RH at 5.870 GHz, while insertion losses decreased by 1.26 dB. The effects of sensing layers thickness as well as trade-off considerations between phase sensitivity and signal attenuation were analyzed by simulation. © 2001-2012 IEEE.

This article presents the accurate modeling results of the nonlinear behavior of a wide range of silicon-based substrates at RF. The TCAD-based model includes carrier inertia effects and captures the transient nonequilibrium phenomena in the semiconductor substrate regions in response to a large-amplitude RF signal. The model is applied to coplanar waveguide (CPW) lines measured on 19 different silicon-based samples that have key differences in their material and interface parameters, such as different values for nominal doping, interface oxide charge, the presence or not of a trap-rich passivation layer, and characteristic dimensions. Furthermore, the CPW line’s distortion levels are measured from 25 °C up to 175 °C and at five fundamental frequencies under large-signal excitation from 50 MHz to 5.4 GHz. An excellent model to experiment correlation is achieved under all of these conditions, and the impact of the material and excitation parameters are discussed with strong physical insight provided by the simulation tool.

This paper investigates a shifting sensing scheme combining slots, transmission lines, and printing technologies. This sensing scheme translates the electrical sensitivity of a transmission line conductor to the insertion phase as a measurement variable. A coplanar waveguide (CPW) based structure was designed, screen-printed, and tested on relative humidity (RH) conditions ranging from 22.8-75.3 %RH. For the first time, a composite material made of poly-pyrrole and TEMPO Oxidized Cellulose Nanofibers (TOCN/PPy) was integrated to the structure and studied as a humidity sensitive conductor in microwave frequencies. The measured sensitivity was 0.154°/%RH at 5.870 GHz, while insertion losses decreased by 1.26 dB. The effects of sensing layers thickness as well as trade-off considerations between phase sensitivity and signal attenuation were analyzed by simulation. © 2001-2012 IEEE.

This paper investigates a shifting sensing scheme combining slots, transmission lines, and printing technologies. This sensing scheme translates the electrical sensitivity of a transmission line conductor to the insertion phase as a measurement variable. A coplanar waveguide (CPW) based structure was designed, screen-printed, and tested on relative humidity (RH) conditions ranging from 22.8-75.3 %RH. For the first time, a composite material made of poly-pyrrole and TEMPO Oxidized Cellulose Nanofibers (TOCN/PPy) was integrated to the structure and studied as a humidity sensitive conductor in microwave frequencies. The measured sensitivity was 0.154°/%RH at 5.870 GHz, while insertion losses decreased by 1.26 dB. The effects of sensing layers thickness as well as trade-off considerations between phase sensitivity and signal attenuation were analyzed by simulation. © 2001-2012 IEEE.

Combined microwave-optical pump-probe methods are emerging to study the quantum state of spin qubit centers and the charge dynamics in semiconductors. A major hindrance is the limited bandwidth of microwave irradiation/detection circuitry which could be overcome with the use of broadband coplanar waveguides (CPW). We present the development and performance characterization of two spectrometers: an optically detected magnetic resonance spectrometer (ODMR) and a microwave detected photoconductivity measurement. In the first method light serves as detection and microwaves excite the investigated medium, while in the second the roles are interchanged. The performance is demonstrated by measuring ODMR maps on the nitrogen-vacancy center in diamond and time resolved photoconductivity in p-doped silicon. The results demonstrate both an efficient coupling of the microwave irradiation to the samples as well as an excellent sensitivity for minute changes in sample conductivity.

Combined microwave-optical pump-probe methods are emerging to study the quantum state of spin qubit centers and the charge dynamics in semiconductors. A major hindrance is the limited bandwidth of microwave irradiation/detection circuitry which could be overcome with the use of broadband coplanar waveguides (CPW). We present the development and performance characterization of two spectrometers: an optically detected magnetic resonance spectrometer (ODMR) and a microwave detected photoconductivity measurement. In the first method light serves as detection and microwaves excite the investigated medium, while in the second the roles are interchanged. The performance is demonstrated by measuring ODMR maps on the nitrogen-vacancy center in diamond and time resolved photoconductivity in p-doped silicon. The results demonstrate both an efficient coupling of the microwave irradiation to the samples as well as an excellent sensitivity for minute changes in sample conductivity.

This paper investigates TEMPO oxidized cellulose nanofibers (so-called TOCN)films as sensitive dielectrics for humidity detection in microwave frequencies. TOCN is used either as a sensitive material or as a host-matrix enclosing polyvinyl alcohol (PVOH)to achieve highly sensitive humidity sensing. A resonator in coplanar waveguide grounded (CPWG)technology was designed and fabricated. TOCN and TOCN/PVOH gels were dropped in the area of the resonator where the analysis showed the electromagnetic field to be maximum at the resonance. Gels became thin films after drying. Experimental humidity tests were then conducted within the 21.9–89.3%RH range, using the resonant frequency and the transmission phase as measurement variables. The best sensitivity with TOCN was 2.67 MHz/%RH regarding the resonant frequency, and 0.523°/%RH regarding the transmission phase. The effects of PVOH were visible starting from 55%RH, where the sensitivity was raised to 6.000 MHz/%RH and 0.785°/%RH respectively. © 2019 Elsevier B.V.

This paper investigates TEMPO oxidized cellulose nanofibers (so-called TOCN)films as sensitive dielectrics for humidity detection in microwave frequencies. TOCN is used either as a sensitive material or as a host-matrix enclosing polyvinyl alcohol (PVOH)to achieve highly sensitive humidity sensing. A resonator in coplanar waveguide grounded (CPWG)technology was designed and fabricated. TOCN and TOCN/PVOH gels were dropped in the area of the resonator where the analysis showed the electromagnetic field to be maximum at the resonance. Gels became thin films after drying. Experimental humidity tests were then conducted within the 21.9–89.3%RH range, using the resonant frequency and the transmission phase as measurement variables. The best sensitivity with TOCN was 2.67 MHz/%RH regarding the resonant frequency, and 0.523°/%RH regarding the transmission phase. The effects of PVOH were visible starting from 55%RH, where the sensitivity was raised to 6.000 MHz/%RH and 0.785°/%RH respectively. © 2019 Elsevier B.V.

This paper investigates TEMPO oxidized cellulose nanofibers (so-called TOCN)films as sensitive dielectrics for humidity detection in microwave frequencies. TOCN is used either as a sensitive material or as a host-matrix enclosing polyvinyl alcohol (PVOH)to achieve highly sensitive humidity sensing. A resonator in coplanar waveguide grounded (CPWG)technology was designed and fabricated. TOCN and TOCN/PVOH gels were dropped in the area of the resonator where the analysis showed the electromagnetic field to be maximum at the resonance. Gels became thin films after drying. Experimental humidity tests were then conducted within the 21.9–89.3%RH range, using the resonant frequency and the transmission phase as measurement variables. The best sensitivity with TOCN was 2.67 MHz/%RH regarding the resonant frequency, and 0.523°/%RH regarding the transmission phase. The effects of PVOH were visible starting from 55%RH, where the sensitivity was raised to 6.000 MHz/%RH and 0.785°/%RH respectively. © 2019 Elsevier B.V.

Planar transmission lines are frequently used to characterize the RF properties of materials. However, the question arises which geometry should be chosen for optimal measurement sensitivity to the material under test. Thus far, this question appears to go unanswered. In this paper, the suitability of the three most popular planar geometries is compared for material characterization. To this end, the impact of a material under test on the apparent properties (i.e. the equivalent homogeneous cross-sections) is examined. This is done for the complex permittivity and the complex permeability, using conformal mapping methods, full-wave simulations and measurements. It is shown that the coplanar waveguide (without conductor backing) is the most suitable structure of the three, since it is the most sensitive to changes in the properties of the material under test.

Planar transmission lines are frequently used to characterize the RF properties of materials. However, the question arises which geometry should be chosen for optimal measurement sensitivity to the material under test. Thus far, this question appears to go unanswered. In this paper, the suitability of the three most popular planar geometries is compared for material characterization. To this end, the impact of a material under test on the apparent properties (i.e. the equivalent homogeneous cross-sections) is examined. This is done for the complex permittivity and the complex permeability, using conformal mapping methods, full-wave simulations and measurements. It is shown that the coplanar waveguide (without conductor backing) is the most suitable structure of the three, since it is the most sensitive to changes in the properties of the material under test.

This paper investigates environment friendly cellulose nanofibres (CNF) as new and sensitive material for humidity sensing in RF/microwave frequencies. CNF sheets were fabricated by sonocatalyzed TEMPO process and physically characterized. Humidity sensing investigation was performed with CNF sheets taped on the top of circuits in coplanar waveguide (CPW) technology. This investigation includes sensitivity and dynamic range analysis with reflected waves along the CPW circuit through resonant frequency shift, and transmitted waves through S21 phase shift. Moreover, sheets with various amounts of CNF were used to study the influence of CNF weight on humidity sensing performances. Regarding the resonant frequency shift, the best sensitivity was measured with the weightier CNF film (71 g/m2), that is 2.82 MHz/%RH from 55%RH to 100%RH. Regarding the phase shift, the same film sensitivity is 0.7°/%RH from 70%RH to 100%RH, with a figure of merit of 7.43°/dB as a phase shifter. © 2017 Elsevier B.V.

This paper presents two types of coplanar transitions based on aluminum nitride (AlN) substrate for interposer designs of terabit transceivers. The designs of coupled coplanar waveguide (CCPW), coupled line, coplanar waveguide (CPW), and coplanar stripline (CPS) based on AlN substrate are explained. The effects of absorber layer and wire bonding bridges are described. Two types of coplanar transitions are designed and simulated in back-to-back configuration with wire bonding bridges. When driven by differential signal pair, the proposed CCPW-to-coupled line transition in back-to-back configuration with wire bonding bridges achieves a simulated return loss of 11 dB and insertion loss of 2 dB up to 110 GHz. As for single-ended signals, a CPW-to-CPS transition in back-to-back configuration with wire bonding bridges has been designed, fabricated, and measured. The fabricated CPW-to-CPS transition can provide a −3 dB transmission bandwidth up to 80 GHz with associated return loss better than 12 dB.

This paper investigates environment friendly cellulose nanofibres (CNF) as new and sensitive material for humidity sensing in RF/microwave frequencies. CNF sheets were fabricated by sonocatalyzed TEMPO process and physically characterized. Humidity sensing investigation was performed with CNF sheets taped on the top of circuits in coplanar waveguide (CPW) technology. This investigation includes sensitivity and dynamic range analysis with reflected waves along the CPW circuit through resonant frequency shift, and transmitted waves through S21 phase shift. Moreover, sheets with various amounts of CNF were used to study the influence of CNF weight on humidity sensing performances. Regarding the resonant frequency shift, the best sensitivity was measured with the weightier CNF film (71 g/m2), that is 2.82 MHz/%RH from 55%RH to 100%RH. Regarding the phase shift, the same film sensitivity is 0.7°/%RH from 70%RH to 100%RH, with a figure of merit of 7.43°/dB as a phase shifter. © 2017 Elsevier B.V.

In this article, we present a freely accessible software tool that allows for fast characterization of dynamic phenomena in a wide variety of transmission lines that include characteristic impedance, effective dielectric constant, and losses, such as radiation into space and surface waves. For printed transmission lines, the radiation effects are of particular importance when the transverse dimensions of the transmission lines become significant in terms of wavelength. Generally, dispersion and losses of the line due to these dynamic phenomena are predicted by full-wave simulations as quasi-static formula do not suffice. The presented software tool, freely downloaded from http://terahertz.tudelft.nl, is capable of accurately analyzing the most widely used transmission lines at high frequencies., Tera-Hertz Sensing

In this article, we present a freely accessible software tool that allows for fast characterization of dynamic phenomena in a wide variety of transmission lines that include characteristic impedance, effective dielectric constant, and losses, such as radiation into space and surface waves. For printed transmission lines, the radiation effects are of particular importance when the transverse dimensions of the transmission lines become significant in terms of wavelength. Generally, dispersion and losses of the line due to these dynamic phenomena are predicted by full-wave simulations as quasi-static formula do not suffice. The presented software tool, freely downloaded from http://terahertz.tudelft.nl, is capable of accurately analyzing the most widely used transmission lines at high frequencies., Tera-Hertz Sensing

This paper presents rectangular waveguide-to-coplanar waveguide (CPW) transitions at U-band (40–60 GHz) using E-plane probe and wire bonding. The designs of CPWs based on quartz substrate with and without aluminum cover are explained. The single and double layer rectangular waveguide-to-CPW transitions using E-plane probe and wire bonding are designed. The proposed rectangular waveguide-to-CPW transition using wire bonding can provide 10 GHz bandwidth at U-band and does not require extra CPWs or connections between CPWs and chips. A single layer rectangular waveguide-to-CPW transition using E-plane probe with aluminum package has been fabricated and measured to validate the proposed transitions. To the authors' best knowledge, this is the first time that a wire bonding is used as a probe for rectangular waveguide-to-CPW transition at U-band.

This paper presents continued research on CPW (coplanar waveguide) meander inductors. The inductors were made in inkjet printing technology. They were printed on polyethylene terephthalate (PET) based substrate (Novele IJ-220), 140 mu m thick. Water-based nanoparticle silver ink (Metalon (R) JS-B25HV) is used for printing. The fabricated inductors have a great value of quality factor (up to 4.2) and high frequency operating range between 1. GHz. 7. GHz for three turn, and 1. GHz -19 GHz for one turn structure. Those characteristics made them suitable for application in flexible electronics.

A shunt series LC resonant circuit based on an open version of an interconnected split ring resonator (OISRR) is proposed. This OISRR exhibits half the resonant frequency of the split ring resonator, allows a parallel connection with a coplanar waveguide (CPW) section and according to its frequency response is an attractive cell for compact CPW notch filter design. 3 dB stop-band bandwidth lower than 4.5% with more than 11 dB insertion loss in the stop-band can be achieved with a CPW loaded with a single OISRR. The experimental results have confirmed the possibilities of this OISRR, which can be easily connected to CPW antennas to reject undesirable signals

In coplanar waveguide (CPW) circuits, printed balanced antennas must be excited through baluns. These baluns often feature coplanar-to-slotline transitions that must be tuned and matched by electromagnetic optimisation, and may interfere with the antenna backward radiation. A new CPW balun for printed balanced antennas is presented and modelled. As its multimodal circuit model makes clear, it integrates an impedance-matching network within its structure that can be analytically designed. The balun has been experimentally tested, exhibiting good agreement with its circuit model and a weak electromagnetic interaction with the antenna radiation., Peer Reviewed, Postprint (published version)

We report a reduction in the frequency noise in coplanar waveguide superconducting resonators. The reduction of 7 dB is achieved by removing the exposed dielectric substrate surface from the region with high electric fields and by using NbTiN. In a model-analysis the surface of NbTiN is found to be a negligible source of noise, experimentally supported by a comparison with NbTiN on SiOx resonators. The reduction is additive to decreasing the noise by widening the resonators., Kavli Institute of Nanoscience, Applied Sciences

We report a reduction in the frequency noise in coplanar waveguide superconducting resonators. The reduction of 7 dB is achieved by removing the exposed dielectric substrate surface from the region with high electric fields and by using NbTiN. In a model-analysis the surface of NbTiN is found to be a negligible source of noise, experimentally supported by a comparison with NbTiN on SiOx resonators. The reduction is additive to decreasing the noise by widening the resonators., Kavli Institute of Nanoscience, Applied Sciences

A novel concept of ultra-broadband multi-stage digital-type microwave MEMS phase shifters with the best performance optimized for W-band applications is introduced in this paper. The relative phase shift of 45ￜ of a single stage is achieved by vertically moving a ?/2-long high-resistivity silicon dielectric block above a 3D micromachined coplanar waveguide (3D CPW) by electrostatic actuation, resulting in different propagation constants of the microwave signal for the up-state and the down-state. For full 360ￜ phase-shift capability, seven stages are cascaded. The devices are fabricated and assembled by wafer-scale processes using bulk and surface micromachining. The measurement results of the first prototypes show that the W-band return and insertion loss of a single 45ￜ stage is better than -15 dB and -1.7 dB, respectively, while the 7-stage phase shifter has a return loss better than -12 dB with an insertion loss less than -4 dB. The phase shifters also perform well from 1- 10 GHz., QC 20111214

An optimized coplanar waveguide fed quasimagnetic printed antenna for ultra wideband applications is described. A parameter study, motivated by a design procedure, allowed a substantial increase in the return-loss operational bandwidth. The numerically predicted performance was validated by means of physical measurements of fabricated samples. The measured radiation patterns of the antenna demonstrated its adequate radiation characteristics. The feed radiation was also investigated by means of physical measurements., Telecommunications, Electrical Engineering, Mathematics and Computer Science

This paper describes a procedure to obtain analytical expressions for the spurious signals generated in nonlinear transmission lines with impedance mismatch when they are subject to small-signals. Using these expressions one can rapidly extract the nonlinear parameters describing the nonlinear effects due to the conductor, L(i) and R(i), such as in superconductors, and/or the nonlinear parameters due to the dielectric, C(v) and G(v) such as in ferroelectrics. The resulting closed-form expressions have been validated by equivalent circuit simulations. Spurious signal measurements on several coplanar waveguide superconducting and ferroelectric transmission lines have been explained by the use of the resulting closed-form expressions., Peer Reviewed

An optimized coplanar waveguide fed quasimagnetic printed antenna for ultra wideband applications is described. A parameter study, motivated by a design procedure, allowed a substantial increase in the return-loss operational bandwidth. The numerically predicted performance was validated by means of physical measurements of fabricated samples. The measured radiation patterns of the antenna demonstrated its adequate radiation characteristics. The feed radiation was also investigated by means of physical measurements., Telecommunications, Electrical Engineering, Mathematics and Computer Science

A broadside coupled (BSC) coupled-line directional coupler based on Composite Right/Left-Handed (CRLH) Coplanar Waveguide (CPW) is proposed. The CRLH CPW on both sides of the substrate comprises of series gap capacitor, broadside-coupled capacitor, and shunt meandering short-circuited stub inductor symmetrically. The new CRLH CPW coupler exhibits a quasi-0-dB coupling over a very wide bandwidth of 89.4% from 6.45 ~ 13.6GHz centered at 8GHz. It is also very compact and symmetrical compared with the conventional designs. An equivalent circuit model including series inductance, capacitance and shunt inductance and capacitance tank also has been established. Good agreement between the full-wave simulation and equivalent circuit model has been achieved and verified the effectiveness of the proposed circuit model., QC 20141015

400nm thick AgTa0.5Nb0.5O3 (ATN) films have been sintered by pulsed laser deposition technique on LaAlO3 (001), sapphire (Al2O3-01 (1) under bar2, r-cut) single crystal substrates and Coming 7059 Glass. Photolithography and metal lift-off technique were used to fabricate tunable Coplanar Waveguide Interdigital Capacitors (CPWIDCs). On-wafer test of varactors was performed with microwave network analyzer and G-S-G microwave probe. ATN/LaAlO3 capacitors demonstrated the highest tunability (similar to 5.8%@20GHz), ATN/Glass showed the best flat dispersion (similar to 3.9%) and ATN/ Al2O3 showed the lowest loss tangent (similar to 0.06@20GHz) in the microwave range from 1 to 40 GHz., QC 20100906

In this paper the packaging of optical components is investigated employing a conductor backed coplanar waveguide (CBCPW). The study is performed using 3D electromagnetic (EM) simulations in a broadband range up to 110GHz. Higher-order resonances are observed in both measurement and simulation results. Based on the verified EM simulation setup, the origin of resonances is identified and remedies are suggested in the paper. Several optimization schemes for achieving good transmission characteristics for the planar structure as well as for the coax-CPW transition are proposed such as properly coating side metallization on the CPW, substrate spacing to the metal housing, and developing metal posts in the substrate of the CPW.

In this paper the packaging of optical components is investigated employing a conductor backed coplanar waveguide (CBCPW). The study is performed using 3D electromagnetic (EM) simulations in a broadband range up to 110GHz. Higher-order resonances are observed in both measurement and simulation results. Based on the verified EM simulation setup, the origin of resonances is identified and remedies are suggested in the paper. Several optimization schemes for achieving good transmission characteristics for the planar structure as well as for the coax-CPW transition are proposed such as properly coating side metallization on the CPW, substrate spacing to the metal housing, and developing metal posts in the substrate of the CPW.

In this paper the packaging of optical components is investigated employing a conductor backed coplanar waveguide (CBCPW). The study is performed using 3D electromagnetic (EM) simulations in a broadband range up to 110GHz. Higher-order resonances are observed in both measurement and simulation results. Based on the verified EM simulation setup, the origin of resonances is identified and remedies are suggested in the paper. Several optimization schemes for achieving good transmission characteristics for the planar structure as well as for the coax-CPW transition are proposed such as properly coating side metallization on the CPW, substrate spacing to the metal housing, and developing metal posts in the substrate of the CPW.

We present comparative characteristics of microwave variable capacitors (varactors) fabricated on Na0.5K0.5NbO3 (NKN), AgTa0.5Nb0.5O3 (ATN) and Ba0.5Sr0.5TiO3 (BST) ferroclectric films sintered by pulsed laser deposition technique. Two port 2 mu m finger gap coplanar waveguide interdigital capacitive (CPWIDC) structures were defined on ferroelectric films surface by a standard lift off technique. Results of the microwave on-wafer tests performed in frequency range 1 to 40 GHz have been examined with a de-embedding technique to extract device characteristics from the measured S-parameters. The frequency dispersion of capacitance was 37%, 4.3%, and 17%; the voltage tunability (200 kV/cm) 22%, 4.7%, and 22% at 20 GHz; loss tangent similar to 0.23, 0.068, and 0.137 at 20 GHz for NKN/Nd:YAlO3, ATN/Al2O3, and BST/Al2O3 films capacitors., QC 20100906

Silver tantalate AgTaO3 (ATO) and silver niobate AgNbO3 (ANO) films have been grown on to the LaAlO3 (001) and sapphire Al2O3 (0112, r-cut) single crystals by pulsed laser deposition technique from stoichiometric ATO and ANO targets. X-ray diffraction study revealed epitaxial quality of ATO and ANO films on the LaAlO3 (00 1) Whereas on the sapphire r-cut substrate they are preferential (I 10) and (00 1) oriented. To characterize microwave films properties in the range from I to 40 GHz, coplanar line interdigital capacitors were fabricated by photolithography and lift-off technique. ANO film capacitors show superior properties: frequency dispersion was as low as 13%, voltage tunability (40 V, 200 kV/ cm) was about 4.6% at 20 GHz, loss tangent similar to 0.106 at 20 GHz, K-factor-tunability/tan delta from 49% @ 10 GHz to 33% at 40 GHz., QC 20100827

In the present paper, a new electromagnetic bandgap (EBG) structure is proposed to design and fabricate low-pass filters on coplanar waveguide (CPW). Using the novel EBG structure, the filter prototypes exhibit sharp cutoff and low insertion loss in the passband. An equivalent lumped L-C circuit mode is introduced to describe the proposed EBG structure, which manifests an elliptic-function low-pass frequency response. Using only three units of this novel EBG cell, a compact low-pass filter device has been fabricated, which achieved sharp cutoff and deep attenuation levels on the stop band. The measured results showed consistency with the simulation using the method of momentum (MoM)., 20141104

This paper reports the micromachining techniques for fabricating edge-suspended RF/microwave passive components, which are proposed to deliver enhanced performance without sacrificing their mechanical strength and reliability. The fabrication incorporates ICP-DRIE dry etching and TMAH anisotropic etching techniques, which are both CMOS compatible. The edge-suspended structures were realized by a TMAH solution consisting of 5 wt\% TMAH, 1.6 wt\% Si and 0.5 wt\% (NH4)(2)S2O8. This solution offers effective etching of silicon along the {100} and {110} planes, while having negligible etching on aluminum and {111} planes. The layout requirement for achieving edge-suspended passive components is also outlined on the basis of the analysis of the anisotropic etching along different crystal orientations. Using the techniques described here, high performance spiral inductors and coplanar waveguides (CPW) with significantly reduced loss are demonstrated. For a three-tum 4.5 nH inductor, a 70\% increase (from 6.8 to 11.7) in maximum Q-factor and a 57\% increase (from 9.1 GHz to 14.3 GHz) in self-resonance frequency are obtained with an 11 mum suspended edge in 25 mum wide lines compared to the conventional inductors without being micromachined. A 50 Omega edge-suspended CPW exhibits a reduction in insertion loss, from 2.4 dB mm(-1) in a conventional CPW to 0.4 dB mm(-1) at 39 GHz.

This paper reports the micromachining techniques for fabricating edge-suspended RF/microwave passive components, which are proposed to deliver enhanced performance without sacrificing their mechanical strength and reliability. The fabrication incorporates ICP-DRIE dry etching and TMAH anisotropic etching techniques, which are both CMOS compatible. The edge-suspended structures were realized by a TMAH solution consisting of 5 wt\% TMAH, 1.6 wt\% Si and 0.5 wt\% (NH4)(2)S2O8. This solution offers effective etching of silicon along the {100} and {110} planes, while having negligible etching on aluminum and {111} planes. The layout requirement for achieving edge-suspended passive components is also outlined on the basis of the analysis of the anisotropic etching along different crystal orientations. Using the techniques described here, high performance spiral inductors and coplanar waveguides (CPW) with significantly reduced loss are demonstrated. For a three-tum 4.5 nH inductor, a 70\% increase (from 6.8 to 11.7) in maximum Q-factor and a 57\% increase (from 9.1 GHz to 14.3 GHz) in self-resonance frequency are obtained with an 11 mum suspended edge in 25 mum wide lines compared to the conventional inductors without being micromachined. A 50 Omega edge-suspended CPW exhibits a reduction in insertion loss, from 2.4 dB mm(-1) in a conventional CPW to 0.4 dB mm(-1) at 39 GHz.

We present the design of a Y-Ba-Cu-O on LiNbO/sub 3/ cryogenic electro-optical modulator for analog 2 GHz applications. A resonant configuration of coplanar electrodes is considered, showing improvements with respect to both resonant Au electrodes and to traveling-wave electrodes, even beyond the traveling-wave theoretical maximum performance limit. The optimized layout is presented featuring a reduced length of 8.26 mm., Peer Reviewed

This paper reports the micromachining techniques for fabricating edge-suspended RF/microwave passive components, which are proposed to deliver enhanced performance without sacrificing their mechanical strength and reliability. The fabrication incorporates ICP-DRIE dry etching and TMAH anisotropic etching techniques, which are both CMOS compatible. The edge-suspended structures were realized by a TMAH solution consisting of 5 wt\% TMAH, 1.6 wt\% Si and 0.5 wt\% (NH4)(2)S2O8. This solution offers effective etching of silicon along the {100} and {110} planes, while having negligible etching on aluminum and {111} planes. The layout requirement for achieving edge-suspended passive components is also outlined on the basis of the analysis of the anisotropic etching along different crystal orientations. Using the techniques described here, high performance spiral inductors and coplanar waveguides (CPW) with significantly reduced loss are demonstrated. For a three-tum 4.5 nH inductor, a 70\% increase (from 6.8 to 11.7) in maximum Q-factor and a 57\% increase (from 9.1 GHz to 14.3 GHz) in self-resonance frequency are obtained with an 11 mum suspended edge in 25 mum wide lines compared to the conventional inductors without being micromachined. A 50 Omega edge-suspended CPW exhibits a reduction in insertion loss, from 2.4 dB mm(-1) in a conventional CPW to 0.4 dB mm(-1) at 39 GHz.

A method is proposed for the analysis of slot antennas excited by coplanar waveguides. First, a standard integral equation for the continuity of the magnetic field is formulated. Then the appropriate equivalent magnetic currents of the method of moments are represented in terms of entire-domain basis functions which synthesize the resonant behavior of the slot and the field in proximity of the feeding source and of the bends. In order to define these basis functions, canonical geometries are identified, whose Green's functions have been found analytically. The accuracy and the effectiveness of the method in terms of convergence rate and number of unknowns is demonstrated by comparison with a standard fine meshing full-wave analysis.