The upper bounds of the signal-to-noise ratio (also known as the "ultimate intrinsic signal-to-noise ratio" (UISNR)) for internal and external coils were calculated. In the calculation, the body was modeled as a dielectric cylinder with a small coaxial cylindrical cavity in which internal coils could be placed. The calculated UISNR values can be used as reference solutions to evaluate the perfo...

This paper presents the results of a new monopole antenna that exhibits 2.75-10.7 GHz performance. The proposed antenna consists of a radiating patch with notches excited by capacitive coupling feed. Also, the antenna’s truncated ground-plane incorporates a central notch. This modification significantly improves the antenna’s impedance bandwidth by 118% over an ultra-wideband frequency range. T...

We synonymize Hellichiella pugach Perkovsky & sukhomlin, 2015 with Gre­ niera yankovskyi Perkovsky & sukhomlin, 2015 (stegopterniini) based on the holotype and female paratype of H. pugach (stegopterniini). Hellichiella po­ lessica n. sp. differs from Hellichiella oligocenica (rubtsov, 1936) (the only species of Hellichiella known in Baltic amber) by its smaller body, narrower head, 11-segmente...

Antenna arrays that receive emissions from spatially spread sources require beamformers with wider beamwidths than point source beamformers. The framework of linearly constrained minimum variance beamforming with quadratic pattern constraints (LCMV-QPC) is used to develop beamformers with a specified main beamwidth and sidelobe levels. The problem is formulated by imposing a set of inequality c...

Transformation optics can be used to design media with unique properties that alter the behavior of electromagnetic waves in passive space and recently in space containing source distributions. We present source transformations where current from a linear radiator is spread over a cylindrical shell with various cross sections. The semianalytic transformations are based on superellipse equations...

Microwave tomographic imaging technology using a bifocusing operator has been developed in order to detect the internal voids/objects inside concrete structures. The imaging system consists of several cylindrical or planar array antennas for transmitting and receiving signals, and a numerical focusing operator is applied to the external signals both in transmitting and in receiving fields. An i...

A new genus of non-biting midges, Tapajos gen. n., is erected for T cristinae sp. n. from the Neotropical region, and placed in the subfamily Chironominae, tribe Chironomini. Adult males are characterized by the combination of bare eyes; antenna with 11 flagellomeres; antepronotal lobes fused medially; fore tibia with inner scale broad and rounded; superior volsella with a long sickle shaped, b...