We present a flexible folded slot dipole implantable antenna operating in the Industrial, Scientific, and Medical (ISM) band (2.4-2.4835 GHz) for biomedical applications. To make the designed antenna suitable for implantation, it is embedded in biocompatible Polydimethylsiloxane (PDMS). The antenna was tested by immersing it in a phantom liquid, imitating the electrical properties of the human muscle tissue. A study of the sensitivity of the antenna performance as a function of the dielectric parameters of the environment in which it is immersed was performed. Simulations and measurements in planar and bent state demonstrate that the antenna covers the complete ISM band. In addition, Specific Absorption Rate (SAR) measurements indicate that the antenna meets the required safety regulations.

Wearable antennas, integrated into garments, are prone to get dirty. Therefore, for the first time in literature, washable antennas are proposed by covering textile antennas by a breathable thermoplastic polyurethane coating, protecting the antennas against water absorption and corrosion. The washability of coated wearable antennas produced by screen printing conductive ink onto a textile substrate is compared to coated wearable antennas based on an electrotextile, analyzing performance in terms of their reflection coefficient and radiation efficiency before and after washing. The combination of screen printing and coating provides stable antenna performance with sufficiently high radiation efficiency after several washing cycles.

A novel dual-band substrate-integrated waveguide (SIW) antenna array topology is proposed for operation in the 28 and 38 GHz frequency bands. Four miniaturized quarter-mode SIW cavities are tightly coupled, causing mode bifurcation, and yielding an antenna topology with four distinct resonance frequencies. A pair of resonances is assigned to both the 28 and 38 GHz band, achieving wideband operation in both frequency ranges. Moreover, owing to the exploited miniaturization technique, an extremely compact array topology is obtained, facilitating easy and straightforward integration. The computer-aided design process yields a four-element antenna array that entirely covers the 28 GHz band (27.5–29.5 GHz) and 38 GHz band (37.0–38.6 GHz) with a measured impedance bandwidth of 3.65 and 2.19 GHz, respectively. A measured broadside gain of 10.1 dBi, a radiation efficiency of 75.75% and a 3 dB beamwidth of 25° are achieved in the 28 GHz band. Moreover, in the 38 GHz band, the measured broadside gain amounts to 10.2 dBi, a radiation efficiency of 70.65% is achieved, and the 3 dB beamwidth is 20°.

This letter proposes a general and effective decoupled technique for the stochastic simulation of nonlinear circuits via polynomial chaos. According to the standard framework, stochastic circuit waveforms are still expressed as expansions of orthonormal polynomials. However, by using a point-matching approach instead of the traditional stochastic Galerkin method, a transformation is introduced that renders the polynomial chaos coefficients decoupled and therefore obtainable via repeated non-intrusive simulations and an inverse linear transformation. As discussed throughout the letter, the proposed technique overcomes several limitations of state-of-the-art methods. In particular, the scalability is hugely improved and tens of random parameters can be simultaneously treated within the polynomial chaos framework. Validating application examples are provided that concern the statistical analysis of microwave amplifiers with up to 25 random parameters.

In this paper, a novel stochastic modeling strategy is constructed that allows assessment of the parameter variability effects induced by the manufacturing process of on-chip interconnects. The strategy adopts a three-step approach. First, a very accurate electromagnetic modeling technique yields the per unit length (p.u.l.) transmission line parameters of the on-chip interconnect structures. Second, parameterized macromodels of these p.u.l. parameters are constructed. Third, a stochastic Galerkin method is implemented to solve the pertinent stochastic telegrapher's equations. The new methodology is illustrated with meaningful design examples, demonstrating its accuracy and efficiency. Improvements and advantages with respect to the state-of-the-art are clearly highlighted.

We present a novel technique to perform variability analysis of multiport systems. The versatility of the proposed technique makes it suitable for the analysis of different types of modern electrical systems (e.g., interconnections, filters, connectors). The proposed method, based on the calculation of a set of univariate macromodels and on the use of the polynomial chaos expansion, produces a macromodel of the transfer function of the multiport system including its statistical properties. The accuracy and the significant speed up with respect to the classical Monte Carlo analysis are verified by means of two numerical examples.