As a promising candidate for rapid and ultrasensitive sensing of biomolecules, terahertz (THz) time-domain spectroscopy is widely used in label-free, noncontact, noninvasive, nondestructive detection. In this article, planar Jerusalem cross metamaterial absorber different virus detection based on spoof surface plasmon polaritons (SSPPs) THz band investigated. Strongly confined SSPPs modes are extracted from the absorption spectra biosensing associated with local field enhancement. Meanwhile,...

A W-band extended interaction oscillator (EIO) driven by a pseudospark-sourced sheet electron beam (PS-SEB) is demonstrated in this letter. The idea of combining the advantages (high current density), geometry (large cross-sectional area), and ladderlike slow wave structure (high-gain per unit length) to generate powerful millimeter-wave radiation was experimentally verified. PS-SEB based EIO produced ~1.2-kW peak output power, an increase six times measured power from on pencil beam. Such...

The study of a planar G-band extended interaction oscillator (EIO) driven by pseudospark-sourced (PS) sheet electron beam is presented. This enables the advantages circuit combined with merits PS beam, including large cross section, high current density and fact that does not require use an external focusing magnetic field. Beam-wave simulations for this EIO predicted peak output power 2.1 kW at ~0.2 THz. Investigations indicate has better tube performance higher radiation compared pencil EIO.

We have recently proposed to combine the advantages of a pseudospark-sourced sheet electron beam (PS-SEB) with planar slow wave structure generate high power terahertz radiation. To verify this idea, experimental investigation an extended interaction oscillator based on PS-SEB has been conducted and presented. A approximately 1.0 mm × 0.17 in size 21.5 peak current (1.26 104 A/cm2 density) 34.5 kV voltage was measured after propagating distance 10-mm without need external focusing magnetic...

Wider bandwidth property of traveling-wave tubes (TWTs) is continuously pursued to satisfy the increased data rates and multiple channels in modern communications. In this paper, coalesced-mode operation instead general single-mode for double staggered grating waveguide (DSGW) slow-wave structure (SWS) proposed achieve an ultrawideband TWTs driven by sheet electron beam. Analytical results high-frequency properties SWS, including dispersion characteristics, interaction impedance,...

A high-power Ku-band TE01 mode gyro-traveling wave tube (gyro-TWT) with a loss loading structure is designed, fabricated, and tested. high beam quality magnetron injection gun generating 68-kV, 20-30-A electron optimized to provide power radiation. novel lossy ceramic loaded selective attenuation ability proposed suppress the potential backward oscillation. The interaction circuit analyzed by linear, nonlinear self-consistent theory, experiment. An improved wideband input design accordingly....

Terahertz (THz) radiation obtained from the interaction between multiple sheet electron beams and a backward wave operating in high-order mode (HOM) provides an effective method to extend frequency power capacity. Suppression of low-order (LOM) competition is one most important issues HOM operation for oscillator (BWO). To address this issue, two ridges were introduced double staggered grating waveguide slow structure (SWS). The dispersion transmission simulations improved SWS showed that...

To accurately measure the performance of dielectric loaded circuits for gyrotron traveling wave tubes, a novel topological structure to generate TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">21</sub> <sup xmlns:xlink="http://www.w3.org/1999/xlink">O</sup> or xmlns:xlink="http://www.w3.org/1999/xlink">01</sub> (superscript represents circular waveguide) mode is proposed and verified in this paper. The topology constituted by an overmoded...

Generally, it is difficult for the common backward wave oscillator (BWO) to produce powerful THz radiation when operating frequency increases a high level such as over 1 due very small structural dimensions. The concept of generating from interaction between high-order mode and multiple sheet electron beams promising solution address issue. For operation, novel orthogonal grating waveguide proposed, which relatively ease fabrication compared with overmoded structure based on double staggered...

Pseudospark-sourced electron beam is a self-focused intense which can propagate without any external focusing magnetic field. This drive beam-wave interaction directly or after being post-accelerated. It especially suitable for terahertz radiation generation due to the ability of pseudospark discharge produce small size in micron range and very high current density bright beams. In this paper, single-gap chamber has been built tested with several electrode gap separations explore dependence...

This paper demonstrates a microwave biosensor, based on the spoof surface plasmon polaritions (SSPPs) excited by planar plasmonic waveguide, which can measure in vivo water content of human skin tissues timely and accurately. A SSPPs biosensor is fabricated measured using vector network analyzer finger as real model. Experimental results with/without normal pure have good agreement with our simulation. The has potential applications for areas measurement stratum corneum topical cosmetics,...

The design, fabrication and cold test of a high frequency system (HFS) for an H-band (220-325GHz) sheet beam travelling wave tube is presented in this article. HFS was composed 90-period double-staggered grating waveguide pair identical L-shaped couplers with Bragg reflectors matching steps. manufactured by nano-computer numerical control machining its electromagnetic properties were measured using vector network analyzer. S-parameters good agreement the simulated ones, which predicted 3 dB...

During its conductive phase, a pseudospark discharge is able to generate low energy electron beam with higher combined current density and brightness compared beams formed from any other known type of source. In this paper, configuration proposed post-accelerate an extracted single-gap cavity in order achieve high quality intense beams. The major advancement that the triggering discharge, itself, post-accelerating are all driven by single voltage pulse. An ∼20 A, 40 kV, duration ∼180 ns has...

A novel methodology of the mode conversion between rectangular TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sub> and xmlns:xlink="http://www.w3.org/1999/xlink">20</sub> based on H-plane T-junction power dividing network is proposed in this paper. converter operating H-band (220-325 GHz) was analyzed designed. To decrease port reflection caused by discontinuity, a septum two symmetric irises were introduced converter. Two identical...

The design of H-band (220-325 GHz) high-order overmoded power couplers for sheet electron beam (SEB) devices is presented in this article. proposed coupler was mainly based on the coupling apertures and possessed functions both mode conversion wave convergence/separation. To compensate junction discontinuity and, thus, reduce port reflection, triangular septa matching steps were introduced. A rectangular Bragg reflector used SEB tunnel to further improve performance coupler. Two identical...

Two power coupling structures based on a Y-type branch waveguide (YTBW) coupler for sheet electron beam devices are presented in this paper. The YTBW is good choice the due to its broad bandwidth property and compact configuration. However, according previous studies, it difficult obtain isolation, small port reflection and, meanwhile, high transmission frequency band. To address issue, following two approaches were proposed: 1) introducing multiple slots between 1 3 of cancel out...

At present, there is a great interest in increasing the power level of terahertz (THz) radiation sources. Aimed to improve output sheet electron-beam devices, sub-THz-band rectangular metal column-loaded double-staggered grating waveguide (RMC-DSGW) proposed this article, which suitable for interaction between high-order overmoded wave and multiple-sheet electron beams. The RMC used suppress adjacent competing modes. To verify idea, TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML"...

In this paper, a terahertz circulator based on magneto photonic crystal slab is envisaged. The triangular lattice crystals with line defect waveguide were constructed an Al2O3 ceramic slab. Two cylindrical ferrites and two copper-clad plates in the junction of Y-shaped wave-guide worked as magneto-optical cavity resonator to approve nonreciprocal function. working frequency range, 0.212–0.238 THz, isolation was better than 20 dB, insertion loss 1 dB. designed experienced low wide bandwidth...

A pseudospark-sourced electron beam is a promising candidate for driving THz millimeter wave radiation source. However, the physics governing density profile and center deviation from axis of structure, which may be caused by randomness in pseudospark discharge process, remains still unclear especially high energy component beam, usually non-mono-energetic. It essential to study position distribution optimizing configuration. In this paper, images some single-shot pulses have been captured...

Based on the previous double-staggered grating waveguide slow-wave structures (SWSs), an improved design is presented in this paper. The linear profile of beam tunnel replaced by a curved shape its broad side. high-frequency characteristics and beam-wave interaction are before after alteration. A novel approach loading attenuator with high attenuation proposed to ensure stable for SWS. From our calculations, SWS possesses larger average impedance rate about 13.1%. Particle-in-cell simulation...

The study of performance improvement for a Q-band sheet-beam traveling-wave tube (SB-TWT) based on an improved double-staggered grating waveguide slowwave structure (SWS) is presented. To enhance the performance, such as reducing driving power requirement and increasing electronic efficiency, three approaches were combined together in design, including making operating frequency be closer to cutoff SWS, improving SWS with curved beam tunnel, introducing phase velocity tapering technique....

A millimeter-waveband double staggered grating waveguide (DSGW) with an arc-shaped beam tunnel was previously proposed for sheet traveling wave tubes. In this article, the design, fabrication, and cold test of a terahertz band DSGW are presented. Simulations demonstrated that novel would have higher coupling impedance better interaction in comparison to conventional linear-shaped tunnel. Beam simulations showed output power electronic efficiency, respectively, increased from ~420 W ~580 7.0%...