Traveling Wave Tubes (TWTs) consist of different elements. The most important element of TWT is the RF circuit. RF circuits in helix TWTs need a dielectric support to hold the helix; this support also has an effect in electromagnetic properties of RF circuits. A novel dielectric support is proposed to reduce the second harmonic of helix TWTs. The dielectric support in this structure consists of...

A Microstrip loop resonator sensor designed to determine the dielectric constant of a liquid is proposed. The resonator sensor designed for 1GHZ for different structure of loop is described. The sensor is implemented using planar microstrip technology. A dielectric material is placed above microstrip ring resonator. As a consequence the near field of the resonator interacts with the material un...

A novel wideband rectangular dielectric resonator antenna (DRA) is proposed in this paper. A hybrid structure with an isolated dielectric resonator (DR) and an equivalent air-dielectric DR is introduced by lifting the resonator from the ground plane. The hybrid structure is excited by a slot-fed mechanism to obtain a smooth transition between each resonant mode. The resonant modes of the isolat...

a compact and sharp-rejection ultra-wideband (uwb) microstrip bandpass filter (bpf) is presented. the proposed filter is constructed with multiple-mode resonator (mmr) and split ring resonator (srr). moreover, proposed structure consists of two doublets parallel coupling gaps at each side of a microstrip ring. in comparison with some other filters, this structure shows a significantly wider pas...

Microstrip patch antennas are well known for their advantages in terms of small weight, low profile and ease of manufacture. However, the main limiting factor in implementing these antennas in many applications is their low impedance bandwidth (typically 2-3%). One popularly used technique of enhancing the bandwidth is to use multi-layered microstrip[1,2]. The most widely accepted structure in ...

In this paper using nested Rectangular resonator we have designed an add-drop filter based on photonic crystal structures suitable for optical communication applications. The drop efficiency and the quality factor of our proposed filter is 100% and 2508. In this filter the quality factor is significantly improved with respect to other published reports. The simulation results are obtained using...

In this pare, a wideband three-order bandpass filter (BPF) is proposed. The proposed wideband filter is designed using the substrate integrated waveguide (SIW) structure by loading T-shape slots. A BPF with two resonators is formed by etching T-shape slots with different size on the top metal plane of the SIW structure. The filter is investigated with the theory of coupled resonator circuits. T...

A quadband filter for 1.57 GHz GPS, 5.2 GHz WLAN and 3.5 GHz Worldwide Interoperability Microwave Access is designed and tested in this work. A compact Defected Ground Structure (DGS) quad-band microstrip Band Pass Filter, stub loaded Low Pass Filter, short circuited uniform impedance resonator and ring resonator are used to maintain the size and performance. Use of stub resonator at central po...

Due to their extraordinary abilities manipulate light propagation at the nanoscale, dielectric resonators that generate electric and magnetic Mie resonances for minimal optical loss have recently attracted great interest. Based on an all-dielectric metasurface, made of H-type silicon nanoarrays, this study proposed constructed a visible-wavelength-range color filter, with high-quality resonance...

We propose and experimentally demonstrate a planar array of optical bandpass filters composed of low loss dielectric metasurface layers sandwiched between two distributed Bragg reflectors (DBRs). The two DBRs form a Fabry-Pérot resonator whose center wavelength is controlled by the design of the transmissive metasurface layer which functions as a phase shifting element. We demonstrate an array ...