Related papers: Physical limitations of phased array antennas
The functional relation between the fractional band-width and the quality factor of a radiating system is investigated in this note. Several widely used definitions of the quality factor are compared on two examples of RLC circuits that…
Performance limitations for implanted antennas, taking radiation efficiency as the metric, are presented. The performance limitations use a convex optimization procedure with the current density inside the implant acting as its degree of…
Sample complexity bounds are a common performance metric in the Reinforcement Learning literature. In the discounted cost, infinite horizon setting, all of the known bounds have a factor that is a polynomial in $1/(1-\gamma)$, where $\gamma…
This paper presents radiation efficiency and gain bounds for microstrip patch antennas. The presented bounds are shown to be good predictors of antenna performance. Using the bounds, patch miniaturization techniques based on high…
In this paper we study microstrip antenna miniaturization using partial filling of the antenna volume with dielectric materials. An analytical expression is derived for the quality factor of an antenna loaded with a combination of two…
The performance of broadband millimeter-wave (mmWave) RF architectures, is generally determined by mathematical concepts such as the Shannon capacity. These systems have also to obey physical laws such as the conservation of energy and the…
Plasmonic nanostructures with singular geometries can exhibit a broadband scattering response that at first glance appears to violate the lower bounds for the radiation quality (Q) factor of small radiators, known as the Chu limit. Here we…
Quantum annealing devices such as the ones produced by D-Wave systems are typically used for solving optimization and sampling tasks, and in both academia and industry the characterization of their usefulness is subject to active research.…
In this paper we propose a new optical ring resonator with a very high Q-factor, to be used as a basic element in a wide range of physics and engineering applications. We theoretically demonstrate that in large size conventional ring…
We estimate the potential size of the weak annihilation amplitudes in QCD factorization as allowed by experimental data. To achieve this goal, we establish a connection between the amplitudes in the QCD factorization and the so-called…
We perform optimization of Q-factor in the system of freestanding three/four/five/six coaxial subwavelength dielectric disks over all scales. Each parameter contributes almost one order of magnitude of the Q-factor due to multiple avoided…
A theory based on the superposition principle is developed to uncover the basic physics of the wave behavior in a finite grating of N unit cells. The theory reveals that bound states in the continuum (BICs) of infinite quality factor…
The effect of electromagnetic retardation on the spectrum of edge plasmons in a semi-infinite two-dimensional electron system is considered. The problem is reduced to complicated integral equations for the potentials, which are solved upon…
This paper deals with the old yet unsolved problem of defining and evaluating the stored electromagnetic energy - a quantity essential for calculating the quality factor, which reflects the intrinsic bandwidth of the considered…
This letter defines a physical bound based array figure of merit that provides a tool to compare the performance of both single and multi-band array antennas with respect to return-loss, thickness of the array over the ground-plane, and…
For a given set of transmitters such as cellular base stations or WiFi access points, is it possible to analytically characterize the set of locations that are "covered" in the sense that users at these locations experience a certain…
We revisit the problem of transmission of quasiparticles through a rectangular potential barrier, for semimetals featuring quadratic-in-momentum band-crossings at a nodal point. Although this was considered in Annals of Physics 419 (2020)…
The correct numerical calculation of the resonance characteristics and, principally, the quality factor $Q$ of contemporary photonic and plasmonic resonant systems is of utmost importance, since $Q$ defines the bandwidth and affects…
Quantum Annealing (QA) is a computational framework where a quantum system's continuous evolution is used to find the global minimum of an objective function over an unstructured search space. It can be seen as a general metaheuristic for…
In this paper it is shown how the equivalent circuit parameters of a MEMS resonator can be simply obtained from an eigenfrequency simulation. Additionally, it is demonstrated that the Q-factor as a result of support losses in a MEMS…