A metasurface-enabled Fabry–Pérot (FP) circularly polarized antenna with continuous wideband polarization conversion purity

In this paper, a wideband continuous pure right hand circularly polarized (RHCP), high gain, and low-radar cross-section (RCS) array antenna is proposed. A linear-to-circularly polarization conversion (LCPC) Metasurface (MS) is employed as the superstrate of the Fabry–Pérot (FP) resonator antenna, consisting of two oblique slits etched patches located at top and bottom, respectively, and a metal ring with corner-cutting patch inside, that ensure a wideband transmission and reflection LCPC frequencies ranging from 9 to 22 GHz, and 7–13.5 GHz, respectively. While, a pure RHCP LCPC frequency band of 9–12 GHz is produced by adopt the proposed MS that is benefit from the design of etched oblique slits and corner-cutting patch surrounded by the metal ring, where the magnitude and phase difference can be kept in the variation of ±3 dB and 10°, respectively. Then, a rectangle patch-fed MS FP antenna is designed by an arrangement of 5 × 5 MS unit cells. Following this, the sequence rotated technique is utilized to arrange the array antenna by 2 × 2 units, ensuring a wide band RCS frequency band. The proposed array antenna is fabricated and measured, which indicated the correctness of this design for performance of high gain, low RCS, and wideband pure RHCP. Compared with recent reported MS-based FP works, a wideband LCPC frequencies purity is obtained, and a good radiation and scattering performance is obtained in the design.

Conferred ownership: approval of financial statements by small charities

Purpose The purpose of this paper is to investigate how trustees of small English registered charities understand and own the reporting and accounting requirements with which their charities must comply. Design/methodology/approach The research described is a multi-pronged qualitative and inductive study of three small Yorkshire charities as they approve their annual accounts. The case studies are based on observations of trustee meetings and interviews with a range of trustees and their independent examiner or auditor. The use of a practice lens focuses on the behaviours of individuals to understand the sense that they make of their charity’s accounts. Findings Trustees' understanding of their financial statements is limited; they tend to rely on key individuals who have knowledge. Group responsibility creates a shared way of understanding the financial statements. Treasurers and independent examiners simplify information for the trustees even resorting to corner cutting and rule bending. Narrative reporting is given very little attention. Trustees read their financial statements as a report to them not by them; accountability notwithstanding, thus ownership of their financial statements is conferred not intrinsic. Research limitations/implications The findings are drawn from three specific case studies and therefore cannot be generalised, but they offer rich qualitative insights into small charities’ accounting and reporting. Originality/value This research provides a unique multi-viewpoint analysis of charity practices, and through its use of a practice lens dives deeper into examining trustees’ understanding and behaviour.

A Class of Trigonometric Bernstein-Type Basis Functions with Four Shape Parameters

In this work, a family of four new trigonometric Bernstein-type basis functions with four shape parameters is constructed, which form a normalized basis with optimal total positivity. Based on the new basis functions, a kind of trigonometric Bézier-type curves with four shape parameters, analogous to the cubic Bézier curves, is constructed. With appropriate choices of control points and shape parameters, the resulting trigonometric Bézier-type curves can represent exactly any arc of an ellipse or parabola. The four shape parameters have tension control roles on adjusting the shape of resulting curves. Moreover, a new corner cutting algorithm is also proposed for calculating the trigonometric Bézier-type curves stably and efficiently.