A new class of wideband ring-type microstrip bandpass filter is proposed under smaller size of three quarters waveguide length section. One via hole is placed at perpendicular positions of a squared ring, whereas two short-circuited sections are formed in the ring-type microstrip bandpass filter similar to a dual-mode ring filter in shape, thereby making up a three quarters waveguide length rin...

Wavelength selective filters represent one of the key elements for photonic integrated circuits (PIC) and many of their applications in linear and non-linear optics. In devices optimised for single polarisation operation, cross-polarisation scattering can significantly limit the achievable filter rejection. An on-chip filter consisting of elements to filter both TE and TM polarisations is demon...

A four port network adder-subtractor module, for surface plasmon polariton (SPP) waves based on a ring resonator filter is proposed. The functionality of module is achieved by the phase difference manipulation of guided SPPs through different arms connected to the ring resonator. The module is designed using the concepts of a basic two-port device proposed in this paper. It is shown that two po...

In this article we introduce the concept of $z^circ$-filter on a topological space $X$. We study and investigate the behavior of $z^circ$-filters and compare them  with corresponding ideals, namely, $z^circ$-ideals of $C(X)$,  the ring of real-valued continuous functions on a completely regular Hausdorff space $X$. It is observed that $X$ is a compact space if and only if every $z^circ$-filter ...

In the present paper a novel structure for optical channel drop filter (CDF) based on photonic crystal ring resonator with circular core has been proposed. In order to design the proposed CDF, the plan wave expansion (PWE) method is applied for calculation of band structure and photonic band gap while the transmission characteristics of proposed CDF have been calculated using the finite differe...

This paper presents the ultrawideband filters for UWB fullband (range of 3.1–10.6 GHz) applications. This filter consists of ring filter for wide-bandwidth and coupled line structure for suppressing unwanted passband in upper and lower stopbands. Especially, the filter structure was realized on silicon substrate using thin film technology, adequate for wafer level packaging, which can be integr...

Bidirectional single longitudinal mode fiber ring laser have advantages and potential in optical sensing, especially angular velocity sensing. The current methods for implementing bidirectional cannot ensure complete reciprocity the path, side suppression ratio needs to be increased, while linewidth is relatively wide. This paper proposes a combined filtering structure using bandpass filter cas...