The helically wrapped circular waveguide

Bunch, K. J.; Grow, R. W.

doi:10.1109/t-ed.1987.23168

Cited by 30 publications

(10 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The conventional helix SWS, its modifications and the coupled cavity SWS have met serious difficulties in satisfying these requirements simultaneously [1] especially when working at millimeter wave band. The helical groove(HG) SWS has attracted scholar's interest widely due to some of its peculiarities [2]: large size, the transverse dimensions comparable to those of coupled cavity structures, super thermal conductivity and high precession of manufacturing and assembling, which make it worth consideration as an alternative SWS at millimeter wave band [2][3][4][5].…”

Section: Introductionmentioning

confidence: 99%

“…The capacitive ridge loading in this structure may reduce the dispersion to some extent. The helical-wrapped circular waveguide, i.e., the half-circular HG [3], has also been analyzed by K. J. Bunch and R. W. Grow.…”

Section: Introductionmentioning

confidence: 99%

“…Recently, there is an increasing interest in variable shape helical groove structure for use as a SWS in TWT [2][3][4][5][6][7][8][9][10]. The authors [6,9] have examined the effect of the groove shape on the dispersion characteristics and interaction impedance properties, indicating its notable influence in the slow-wave regimes.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The Small Signal Analysis of a Centered Dielectric-Rod Loaded, Arbitrarily-Shaped Helical Groove Traveling-Wave-Tube

Wei

Liu

et al. 2007

Int J Infrared Milli Waves

View full text Add to dashboard Cite

Properties of traveling wave-beam interaction in a centered dielectric-rod loaded, arbitrarily-shaped helical groove slow-wave structure (SWS) are investigated for a thin annular electron beam. The "hot" dispersion equation is obtained by means of the selfconsistent field theory, and the small signal analysis is carried out including the effects of the dielectric-rod parameters and the groove shapes. The numerical results show that the bandwidth of the helical groove TWT is expanded by loading dielectric-rod, however, the small-signal gain is reduced; and when the groove shape changes from the swallow-tail shape to the triangle shape, the working frequency increases , while the peak gain decreases.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The Small Signal Analysis of a Centered Dielectric-Rod Loaded, Arbitrarily-Shaped Helical Groove Traveling-Wave-Tube

Wei

Liu

et al. 2007

Int J Infrared Milli Waves

View full text Add to dashboard Cite

show abstract

“…The idea of a helical optical waveguide [20,21] in the field of optical fiber technology stems from the travelling wave tube technology (TWT) in the microwave region [22,23]. In that field, however, slow wave structures are used.…”

Section: Introductionmentioning

confidence: 99%

Conducting Sheath Helical Winding on the Core-Cladding Interface of a Lightguide Having a Piet Hein Super Elliptical Core Cross-Section and a Standard Optical Fiber of Circular Cross-Section-a Comparative Modal Analysis

Singh¹,

Maurya²,

Prasad³

et al. 2006

PIER

View full text Add to dashboard Cite

Abstract-In this article, a theoretical and computational analysis has been made to obtain the modal dispersion characteristics of an unconventional optical waveguide with a Piet Hein core cross section having a conducting sheath helix winding on its core-cladding boundary. A simple analytical method using the vector boundary conditions has been utilized to get the modal eigen value equation. From this equation dispersion curves are obtained and plotted for some particular values of the pitch angles of the winding. Next, these predicted results are compared with those of a new optical fiber having a conducting sheath helix winding on its core-cladding boundary. It is seen that the cutoff values are somewhat lower for the Piet Hein lightguide than those for the circular guide. This is not unexpected since the Piet Hein curve approaches the shape of a square. The introduction of a conducting helical winding leads to a modification of the modal characteristics of the lightguides and gives us an additional means to control them.

show abstract

“…Many authors have worked in this field [11][12][13][14][15][16][17][18][19][20], in which there is a wide application of helical waveguides in various ranges, and they have been found with a better performance in gain and bandwidth. A theory in the field of helically wrapped circular waveguides has been investigated by Bunch et al [11], and it is used as a slow structure within the microwave amplifier. Singh et al [14] proposed a circular waveguide with conducting helical cladding and made a comparison with the standard step-index waveguide, and reported that the number of modes is reduced.…”

Section: Introductionmentioning

confidence: 99%

A theoretical analysis of the propagation characteristics of an annular circular waveguide with a helical winding as the inner cladding

Kumar

Srivastava

Ojha

2003

Micro & Optical Tech Letters

View full text Add to dashboard Cite

ing a drain current peak higher than I D,max have been ruled out. The optimum combinations of v gs and R S for a self-biased doubling device are represented by the left ends of the secondharmonic contour lines. In fact, at such points the required performance is achieved by fulfilling minimum RF input power and R S power dissipation, and maximum GS , thus preventing the minimum gate-source voltage to reach breakdown. The generated design chart has been used to select the source-bias resistor and the ac gate-source voltage level of the doubling device. The selected values are 30⍀ and 1.1 V, respectively, corresponding to a secondharmonic drain-current component of 23 mA. In particular, the gate-source voltage mean time value is Ϫ0.9 V; a minimum gate-source voltage of Ϫ2 V is therefore achieved, obtaining a good margin with respect to the breakdown of the device. The drain bias resistor has been computed using Eq. (2), in which V DD ϭ 4 V and the drain-source mean-time value is 2.5 V, corresponding to the middle point between the breakdown and knee region of the dc-output device characteristic. A drain resistor R D ϭ 20⍀ has been obtained.The buffer-device bias resistors have been selected to bias the active device for class A operation, in order to achieve high linearity.Circuit-matching networks have been designed to match the overall circuit and optimally load input and output terminals of the doubling device [5]. The output network has been designed to obtain a broadband match of the circuit output. The interstage network has been designed to match, under large signal operation, the output of the doubling device to the buffer input at secondharmonic frequency, and to load the output of the doubling device at fundamental frequency for maximum conversion gain. Finally, the input network is conjugately matched at fundamental frequency to the device input for maximum power transfer and at second harmonic for maximum conversion gain. In particular, a series resistance acting as an attenuator has been introduced to reduce the specified input-power level to the optimum-doubling level.The proposed doubler has been realized using 0.25-m GaAs PHEMT technology by UMS. The photograph of the circuit is shown in Figure 3, and the size of the chip is 2 ϫ 1.4 mm 2 . MEASUREMENT RESULTSMeasured doubler-conversion gain and the fundamental rejection for an input power of 11 dBm at 5.5 GHz are depicted in Figure 4. A conversion gain in excess of 1 dB and a fundamental rejection higher than 17 dB over a bandwidth of 27% is demonstrated. The circuit is fed with a power supply of 4 V and a drain-current mean-time value of 26 mA has been measured for the doubling device. In the absence of an RF input signal, a drain bias current of 18 mA and 30 mA have been measured for the doubling and buffer stages, respectively. CONCLUSIONA new approach for frequency doubler design that minimizes of the complexity of a system's control circuitry, has been proposed, and a design method for this type of circuit has been developed. The effectiveness ...

show abstract

The helically wrapped circular waveguide

Cited by 30 publications

References 3 publications

The Small Signal Analysis of a Centered Dielectric-Rod Loaded, Arbitrarily-Shaped Helical Groove Traveling-Wave-Tube

The Small Signal Analysis of a Centered Dielectric-Rod Loaded, Arbitrarily-Shaped Helical Groove Traveling-Wave-Tube

Conducting Sheath Helical Winding on the Core-Cladding Interface of a Lightguide Having a Piet Hein Super Elliptical Core Cross-Section and a Standard Optical Fiber of Circular Cross-Section-a Comparative Modal Analysis

A theoretical analysis of the propagation characteristics of an annular circular waveguide with a helical winding as the inner cladding

Contact Info

Product

Resources

About