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In this article, the dielectric properties of a biosourced polymer are investigated. To that end, coplanar transmission lines were fabricated on a 600- $\mu \text{m}$ thick cellulose palmitate substrate by using a photolithographic process and a transfer technique. The ${S}$ -parameters of the transmission lines were measured in a broad microwave frequency band spanning from 10 to 67 GHz in order to determine the propagation constant. From these data, the complex dielectric permittivity was extracted by using two analytical methods (RLCG method, based on resistance, inductance, capacitance and conductance of transmission lines and conformal mapping method) and a numerical one [finite element method (FEM)]. The three methods allow distinguishing the dielectric losses from the total measured losses of the transmission lines. Finally, the dielectric constant and the loss tangent of this biopolymer were compared to the data of common and commercially available substrates: polyimide and polyethylene naphthalate. [ABSTRACT FROM AUTHOR]

Microwave imaging of nanoelectronic devices has turned a simple reflection coefficient measurement, usually carried out by a 50- $\Omega $ vector-network analyzer, into a high-impedance instrumentation challenge. Interferometry-based reflectometers (IBR) have been found to be successful solutions in addressing this challenge. However, such solutions do not consider instrumentation of high impedance and high frequency as well as minimization of environment variations in a comprehensive manner. In this paper, these aspects are addressed jointly through the proposal of a fully integrated IBR in the STMicroelectronics BiCMOS 55-nm technology. Three varactor samples having a capacitance ranging from 0.65 to 0.95 fF are measured at 17.6 GHz for demonstration. The fully integrated IBR achieved a magnitude error below −35 dB, a phase error below 0.03°, and an accuracy better than 59.7 aF. Moreover, $C$ – $V$ slope measurement error is better than 2.8 aF, which is ten times smaller than found in the state-of-the-art IBR. Such betterment is explained by the monolithic integration of IBR and device-under-test as implemented in this paper. [ABSTRACT FROM AUTHOR]

One of the major challenges in wireless communication technologies is the antenna design. In this paper, a wideband flexible antenna made by covering a Kapton substrate with a flexible magnetodielectric polymer-based nanocomposite layer is proposed. This novel magnetodielectric polymer-based nanocomposite relies on carbon-coated cobalt (CCo) and is coated with a conjugated polymer, polyaniline (PANI). The nanocomposite (PANI/CCo) fabrication, whose morphology was studied via scanning electron microscopy, demonstrates a relative permeability, a dielectric permittivity, and a conductivity of 5.5, 4.3, and 7500 S/m, respectively. In this paper, two frequency bands are of interest [1.8–2.45 GHz (personal communication service and wireless local area network) and 5.15–5.825 GHz (wireless networks)]. The functioning of the antenna in free space and on body is numerically and experimentally investigated. The average specific absorption rate is also discussed. Thanks to its performance this magnetodielectric nanocomposite polymer (PANI/CCo) antenna has been found to be a good candidate for wearable applications where complex bending situations are encountered. [ABSTRACT FROM AUTHOR]

In this paper, the impact of different setting parameters on the performance of a microwave microscope is evaluated. This study is performed on a homemade near-field scanning microwave microscope built up with a conventional vector network analyzer and a vertical coaxial evanescent probe. A broadband matching network based on an interferometric technique is inserted between the analyzer and the probe to enhance the measurement sensitivity/accuracy in the frequency range 2–20 GHz. The performance of the system in terms of measurement accuracy and stability is derived as a function of different setting parameters. Microwave surface imaging of subwavelength features is evaluated as a demonstration. This paper provides a guide for best practice in microwave microscopy. [ABSTRACT FROM AUTHOR]

A technology of planar micro thermoelectric generators ( \mu \mathrm T\mathrm E Gs) with double thermal deflections is presented in this letter. We focus on the development of an original technic of bonding pillars etched on a first silicon wafer onto the fragile membranes of a second silicon wafer. The monolithic devices realized are able to convert waste heat into electrical power. The maximum output power for a five-membranes-based $\mu $ TEG is $12.3~\mu $ W/cm2, for an input power of 2 W/cm2. This kind of $\mu $ TEG has a high thermal resistance. It is deduced to be 44.3 K/W, which allows a heat adaptation to any environment with a high thermal resistance. [2016-0066] [ABSTRACT FROM AUTHOR]

A microwave free-space reflection method for determining the complex permittivity of planar dielectric materials is demonstrated. The method makes use of the measurement of the near-field microwave reflection coefficient of a metal-backed sample. The modeling of the structure and its calibration are based on geometrical optics considering spherical electromagnetic waves propagating through the material. The technique that presents a number of features such as low-cost, compactness, robustness, and reliability is a good candidate for industrial applications. As a demonstration, dielectric parameters extraction of building materials is experimentally demonstrated for wireless local area network operations in the 2.45- and 5-GHz bands. [ABSTRACT FROM PUBLISHER]

An interferometric technique for scanning near-field microscopy applications is proposed. The method is based on the association of a vector network analyzer, an evanescent microwave coaxial probe and a precise interferometer built up with a power divider, a phase-shifter, and an attenuator. Advantages, such as simplicity of operation, broad frequency band capabilities and high measurement sensitivity are achieved. In particular, a scanning near-field microwave microscope is built and experiments related to the measurement sensitivity in the frequency range 2–6 GHz are demonstrated. A lumped element model is also performed to represent the interaction between the probe and sample. A one port calibration model is developed to retrieve the reflection coefficient and then the electromagnetics properties of the sample. [ABSTRACT FROM PUBLISHER]

Scaling of electronic device dimensions into the nanoscale regime has been at the basis of the semiconductor industry for several decades. Traditional materials have been pushed to their limits, which means that entirely new materials and new device structures are now required. The development of emerging technologies that include quantum confinement, spin transport, and molecular or correlated materials places increasingly stringent requirements on metrology of these novel devices. Advances in fundamental nanoscience, design of new nanostructures, and progresses in manufacturing of next-generation nanodevices will all depend on our ability to measure accurately and reproducibly the properties and performance characteristics at the nanometer scale over a wide frequency range. [ABSTRACT FROM PUBLISHER]

A multiport based near field high frequency microscope is proposed for local nondestructive evaluation and testing applications. The combination of the multiport technology and near-field microscopy methods present advantages such as low cost, compactness, real-time operation, high spatial resolution and versatility. In particular, experimental demonstrations of a multiport near-field microscope is described in microwave frequency range. The spatial resolution of the instrument is experimentally verified to evaluate the performance of the technique proposed. [ABSTRACT FROM PUBLISHER]

A complete microwave characterization up to 67 GHz using specific coplanar waveguides was performed to determine the dielectric properties (permittivity, losses, and tunability) of sapphire/TiOx/Ba0.3Sr0.7TiO3 (BST) (111)-oriented thin films. To that end, BaxSr1?xTiO3 thin films were deposited by RF magnetron sputtering on sapphire (0001) substrate. To control the preferred (111) orientation, a TiOx buffer layer was deposited on sapphire. According to the detailed knowledge of the material properties, it has been possible to conceive, fabricate, and test interdigitated capacitors, the basic element for future microwave tunable applications. Retention of capacitive behavior up to 67 GHz and a tunability of 32% at 67 GHz at an applied voltage of 30 V (150 kV/cm) were observed. The Q-factor remains greater than 30 over the entire frequency band. The possibility of a complete characterization of the material for the realization of high-performance interdigitated capacitors opens the door to microwave device fabrication. [ABSTRACT FROM AUTHOR]

An accurate technique for six-port reflectometers calibration is presented in this paper. The method based on a spatial Fourier analysis incorporates nonlinearity and mismatching effects as a part of the calibration procedure. The technique makes use of impedance data distributed on the whole Smith chart to increase the measurement accuracy. A straightforward least square algorithm is used to fully calibrate the six-port reflectometer. Experimental data in the millimeter-wave frequency range is provided to validate the technique. [ABSTRACT FROM AUTHOR]

This paper presents two new structures for four-port-based systems with ultrawide operating bandwidth, using a combination of power dividers and delay lines. The prototype circuits, initially conceived to operate in the frequency band from 1 to 4 GHz, are fabricated to validate these new architectures by means of a hybrid integrated-circuit technology. Associated with these systems, a new explicit calibration solution is developed to extend the frequency band of use up to 10 GHz. Comparison between the results obtained from the new structures with those given by a conventional network analyzer show the validity of the systems proposed. [ABSTRACT FROM AUTHOR]

In this letter, a grounded coplanar waveguide-to-microstrip (GCPW-to-MS) transition without via holes is presented. The transition is designed on a PET® substrate and fabricated using inkjet printing technology. To our knowledge, fabrication of transitions using inkjet printing technology has not been reported in the literature. The simulations have been performed using HFSS® software and the measurements have been carried out using a Vector Network Analyzer on a broad frequency band from 40 to 85 GHz. The effect of varying several geometrical parameters of the GCPW-to-MS on the electromagnetic response is also presented. The results obtained demonstrate good characteristics of the insertion loss better than 1.5 dB, and return loss larger than 10 dB in the V-band (50–75 GHz). Such transitions are suitable for characterization of microwave components built on different flexible substrates. [ABSTRACT FROM PUBLISHER]

Nanometer-scaled communication devices for microwave and millimeter wave applications motivated innovative techniques in modeling and characterization. In this letter, an interferometry-based reflectometer (IBR), comprising Vector Network Analyser (VNA) and commercial devices, is implemented. Using sub-fF 130 nm thick-oxide accumulation MOS varactors from ST Microelectronics, IBR and VNA measurements are compared to a silicon-based model. A capacitance from 0.9 to 1.6 fF around 6.8 GHz is estimated. IBR demonstrates a root-mean-squared (RMS) error related to silicon-based model of 60 aF, while VNA has 70 aF in its best case. The mean accuracy is estimated at 40 aF and 11 aF respectively for VNA best case and IBR in C-V measurements. This letter demonstrates that IBR solution has smaller RMS error and better accuracy for C-V measurements than VNA. [ABSTRACT FROM PUBLISHER]

A compact multiport reflectometer using a new subtractive mixing scheme for the determination of reflection coefficients in the frequency range of 1–10 GHz is proposed. Compared with classical multiport reflectometers, the architecture proposed reduces the design complexity. Comparison between experimental results obtained from the proposed reflectometer and those given by a conventional network analyzer is given. [ABSTRACT FROM PUBLISHER]