Your browser does not support JavaScript!
http://iet.metastore.ingenta.com
1887

IEE Proceedings H (Microwaves, Optics and Antennas)

Volume 127, Issue 6, December 1980

Volumes & issues:

Volume 127, Issue 6

December 1980

Accurate formulas for computer-aided design of shielded microstrip circuits
  • Author(s): S.S. Bedair  and  M.I. Sobhy
  • Source: IEE Proceedings H (Microwaves, Optics and Antennas), Volume 127, Issue 6, p. 305 –308
  • DOI:  10.1049/ip-h-1.1980.0065
  • Type: Article
  • + Show details - Hide details
  • p. 305 –308 (4)
    Design equations are derived for the calculation of capacitance, characteristic impedances, and effective dielectric constants of single and coupled shielded microstrip. The equations are in closed form and hence they are suitable for direct use in computer-aided procedures for the design of microwave circuits containing these elements. Results obtained using these equations agree well with those obtained by numerical techniques. The present method could either be used to compensate for the effect of the shield on the performance of the circuit, or to design circuits whose characteristics could be controlled by varying the shield height. A computer-aided circuit optimisation procedure has been developed and examples are given of circuits designed using these equations. Practical measurements show good agreement with theoretical calculations and the effect of varying the shield heights on the performance of the circuit is demonstrated.
    Add to favourites
    Export citations
Matrix theory for n-line mxicrowave coupler design
  • Author(s): J.E. Carroll  and  P.R. Rigg
  • Source: IEE Proceedings H (Microwaves, Optics and Antennas), Volume 127, Issue 6, p. 309 –314
  • DOI:  10.1049/ip-h-1.1980.0066
  • Type: Article
  • + Show details - Hide details
  • p. 309 –314 (6)
    The matrix equations respresenting wave propagation along a multiconductor system of transmission lines are solved giving expressions for the scattering parameters in terms of the parameters of the lines themselves. We demonstrate the extensions and generalisations of co- and contradirectional coupling, coupled-mode theory and also the concept of the non-mode-converting termination to multiline systems. Concentrating on the simplifying assumption of weak reflections at the terminations we extend the weak coupling approximation of coupled-mode theory to allow for strong coupling between adjacent lines. A demonstration of this is given in the design of a three-line equal power splitting coupler with an arbitrary phase shift between output ports at the centre frequency.
    Add to favourites
    Export citations
Three-line broadband codirectional microwave couplers using planar comb and herringbone microstrip lines
  • Author(s): P.R. Rigg  and  J.E. Carroll
  • Source: IEE Proceedings H (Microwaves, Optics and Antennas), Volume 127, Issue 6, p. 315 –322
  • DOI:  10.1049/ip-h-1.1980.0067
  • Type: Article
  • + Show details - Hide details
  • p. 315 –322 (8)
    Equations relating the scattering parameters to the line parameters of an n-line system of coupled transmission lines are applied to the design and construction of three-line broadband codirectional microwave couplers using planar comb and herringbone microstrip structures. Theoretical curves are produced for the scattering parameters of equal power splitting couplers with a range of output phase differences at the centre operating frequency. A broadband coupler is achieved with a phase difference of π radians between the output ports at the centre frequency. The bandwidth is ± 65% which is the largest so far reported for a single section uniform device. Three couplers are constructed using various dielectric materials and their performances measured using a time domain automatic network analyser (t.d.a.n.a.), a relatively new broadband microwave measurement technique. One of the couplers is designed to transform the impedance level from 50 Ω at the input to 25 Ω at the output ports. A possible application of the coupler is demonstrated in microwave GaAs. f.e.t. amplifier design and results are given for a two-device circuit operating around 3 GHz.
    Add to favourites
    Export citations
Optimisation of a collinear acoustooptic TEm-TEn mode convertor LiNbO3
  • Author(s): L.N. Binh  and  J. Livingstone
  • Source: IEE Proceedings H (Microwaves, Optics and Antennas), Volume 127, Issue 6, p. 323 –329
  • DOI:  10.1049/ip-h-1.1980.0068
  • Type: Article
  • + Show details - Hide details
  • p. 323 –329 (7)
    An analysis is given of the optimisation of the mode conversion of guided optical waves resulting from interaction with collinearly travelling surface acoustic waves of Rayleigh type. The effects of electrooptic and acoustooptic index fluctuations together with the phase matching condition and interaction lenghts are considered. Design criteria and numerical results are given. A number of acoustooptic mode converters are then demonstrated experimentally. A 50% conversion efficiency is obtained for TE1–TM1 conversion in LiNbO3 with acoustic input power of 10 mW. Angular dispersion of laser light has been found to reduce the effective interaction length and this is demonstrated and discussed.
    Add to favourites
    Export citations
Flat disc, radially nonhomogeneous, lenses
  • Author(s): S. Cornbleet
  • Source: IEE Proceedings H (Microwaves, Optics and Antennas), Volume 127, Issue 6, p. 330 –334
  • DOI:  10.1049/ip-h-1.1980.0069
  • Type: Article
  • + Show details - Hide details
  • p. 330 –334 (5)
    A plane surfaced lens can be constructed through the use of radially nonhomogenous medium, with axial symmetry. The rays from an axial source are incident on the plane front surface, perpendicular to the axis, where the assumption is made that the rays obey Snell's laws locally as for an infinite uniform medium. The curved ray paths are then given by the standard ray integral and are taken up to the point where each ray becomes horizontal. For certain polynomial functions describing the refractive index, the ray integral is an incomplete elliptic integral of the first kind, and trial functions can be inserted, such that the rays have become horizontal all at a second plance surface, thus creating a flat disc lens. The total sysmmetry of the design provides for many advantageous properties.
    Add to favourites
    Export citations
Book review: Fiber and Integrated Optics
Optical waveguide filters for the visible spectrum
  • Author(s): A. Yi-Yan ; J.A.H. Wilkinson ; C.D.W. Wilkinson
  • Source: IEE Proceedings H (Microwaves, Optics and Antennas), Volume 127, Issue 6, p. 335 –341
  • DOI:  10.1049/ip-h-1.1980.0071
  • Type: Article
  • + Show details - Hide details
  • p. 335 –341 (7)
    A study has been made of wavelength selective devices which use a grating structure superimposed on a thin film optical waveguide. Good agreement was found between the theoretical and experimental wavelength response of filters in three forms of optical waveguide: with the grating ion-beem etched into a single homogeneous guiding layer, with the grating in a photoresist film on a homogeneous layer and with the grating in a photoresist film on a silver ion-exchanged waveguide. Details of the method of fabrication of the gratings and waveguides are given. Filters made with gratings ion-beanm etched into waveguide had bandwidths of 0.2 to 0.5 nm at 600 nm while the filters with superimposed gratings in photoresist had somewhat wider bandwidths.
    Add to favourites
    Export citations
Pseudoelliptical phase-equalised filter allowing good optimisation for both phase and amplitude response
Design procedure for multioctave combline-filter multiplexers
  • Author(s): S.A. Alseyab  and  J.D. Rhodes
  • Source: IEE Proceedings H (Microwaves, Optics and Antennas), Volume 127, Issue 6, p. 346 –353
  • DOI:  10.1049/ip-h-1.1980.0073
  • Type: Article
  • + Show details - Hide details
  • p. 346 –353 (8)
    A new general design procedure is presented for multioctave multiplexers having any number of combline channel filters satisfying an equiripple response, with an arbitrary number of resonators, bandwidths, and interchannel spacings. The design procedure is developed for bandpass combline filters connected in series at a common junction for broadband applications. Commencing with the expression for element values of a double-terminated-bandpass prototype combline filter satisfying an equiripple response, the multiplexer design procedure modifies the elements in the nearer half to the common junction of each channel filter and preserves a match at the two points of perfect transmission closest to the band edges of each channel filter, while taking into account the frequency dependence across each channel. Examples of several multiplexers are given indicating that the design process is valid for a wide variety of specifications and gives very good results as demonstrated by the computer analysis of multiplex multiplexer examples and by the experimental example of a combline-filter diplexer constructed in a coaxial form of realisation.
    Add to favourites
    Export citations
Variational bound principle for irregular waveguides

Most viewed content for this Journal

Article
content/journals/ip-h-1
Journal
5
Loading

Most cited content for this Journal

We currently have no most cited data available for this content.

Print this page
This is a required field
Please enter a valid email address