In this paper, a new Ultra-Wideband (UWB) Band-Pass Filter (BPF) for UWB applications is presented. The proposed filter is based on ring resonator with inter-digital coupling at both sides. The inter-digital coupling is used to providing strong coupling and to introduce capacitance effect to achieve at pass-band response. To achieve band rejection characteristics L-shaped open stubs are incorpo...

in this paper, we introduce a class of $j$-quasipolar rings. let $r$ be a ring with identity. an element $a$ of a ring $r$ is called {it weakly $j$-quasipolar} if there exists $p^2 = pin comm^2(a)$ such that $a + p$ or $a-p$ are contained in $j(r)$ and the ring $r$ is called {it weakly $j$-quasipolar} if every element of $r$ is weakly $j$-quasipolar. we give many characterizations and investiga...

We propose and demonstrate a stable single-longitudinal mode (SLM) thulium-doped fiber laser (TDFL) with Fabry- Pérot (F-P) Bragg grating (FBG) filter triple-coupler based double-ring cavity (TC-DRC) filter. For the first time, this structure of TC-DRC is used to select single from dense longitudinal-modes in ring TDFL. The design fabricate methods are revealed principle SLM selection also anal...

in this paper, we investigate various kinds of extensions of twin-good rings. moreover, we prove that every element of an abelian neat ring r is twin-good if and only if r has no factor ring isomorphic to z2  or z3. the main result of [24] states some conditions that any right self-injective ring r is twin-good. we extend this result to any regular baer ring r by proving that every element of a...

High quality filters are essential part of vocoders. By means of filter banks structures we can combine modem DSP algorithms with hardware realizations having many parallel identical devices. This paper proposes digital filter realization based on filter bank structure suitable for hardware realization.

This paper addresses a modified bandpass ring resonator filter providing compact size, low insertion-loss, wide bandwidth, sharp rejection and suppressed higher order modes. Typically, ring resonator filters suffer from large occupation area and limited out of band rejection. These limitations are tackled in this work by means of a threefold approach. On the one hand, the use of internal folded...

By using a composite coupling structure for coplanar waveguide (CPW)/microstrip, a new dual-band bandpass filter (DBBPF) stacking inverted Y-shaped CPW resonators and rectangular ring resonators is proposed. Two resonant frequency bands are simultaneously excited by the CPW feed line. However, it can be convenient to tune individually. Several transmission zeros are realized to improve the sele...

This paper presents the design and realization of a multifunctional bandpass-filter/displacement-sensor using an edge-coupled microstrip bandpass filter loaded by pair split ring resonators (SRRs). It is shown that while structure acts as at its operating frequency, phase reflection coefficient from movable loading resonator resonance frequency can be used for displacement sensing. With this ai...

This paper presents a compact tunable bandpass filter that is based on open split ring resonator to achieve high out-of-band rejection. Exact equations and design procedures are given based on strict theoretical analysis. By loading the varactor diodes, the center frequency and bandwidth of the bandpass filter could realize reconfigurable. Then defected ground structure was adopted in the input...

We demonstrate pulsewidth-stretchable Er-doped femtosecond mode-locked fiber lasers by incorporating a tunable short-pass edge filter into the ring cavity. Pulsewidth stretch ratio of 3.53 (882/250) can be efficiently achieved under a temperature variation of 4oC.