A New Theory of the Characteristic Impedance of General Printed Transmission Lines Applicable when Power Leakage Exists

Research output: Contribution to journalArticle

Abstract

Conventional definitions of the characteristic impedance, such as the voltage-current, power-current, and power-voltage methods, which have been commonly used for standard nonleaky transmission lines, become invalid when power leakage occurs. In this paper, we present a new theory of the characteristic impedance for printed transmission lines, applicable under the general conditions with or without power leakage. The theory is founded on dual field and circuit theories of transmission lines, formulated in the spectral domain, and uses a new approach called "the wavenumber perturbation approach." In order to correctly compute the complex characteristic impedance under leakage conditions, the new theory requires to carefully "extract out" the surface-wave or parallel plate-wave poles on the complex k-plane. In obvious difference to this, it is well known that the poles must be "included" for a correct solution of the complex propagation constant of the leaky line. Incidentally, unlike the conventional methods, the new theory derives the complex characteristic impedance together with the solution of the phase and attenuation constants, in a single unified procedure. This avoids additional efforts in computational or analytical/formulational complexity. Results for selected cases of interest are presented, which demonstrate the validity and simplicity/elegance of the new theory.

Original languageEnglish (US)
Pages (from-to)1108-1117
Number of pages10
JournalIEEE Transactions on Microwave Theory and Techniques
Volume48
Issue number7 PART 1
DOIs
StatePublished - 2000

Fingerprint

transmission lines
Electric lines
leakage
impedance
Poles
poles
Circuit theory
Electric potential
Surface waves
electric potential
parallel plates
surface waves
attenuation
perturbation
propagation

Keywords

  • Characteristic impedance
  • Leaky waves
  • Planar transmission line
  • Slotline
  • Stripline

ASJC Scopus subject areas

  • Electrical and Electronic Engineering

Cite this

@article{974636dfeae741b69ed98d18f7fc974d,
title = "A New Theory of the Characteristic Impedance of General Printed Transmission Lines Applicable when Power Leakage Exists",
abstract = "Conventional definitions of the characteristic impedance, such as the voltage-current, power-current, and power-voltage methods, which have been commonly used for standard nonleaky transmission lines, become invalid when power leakage occurs. In this paper, we present a new theory of the characteristic impedance for printed transmission lines, applicable under the general conditions with or without power leakage. The theory is founded on dual field and circuit theories of transmission lines, formulated in the spectral domain, and uses a new approach called {"}the wavenumber perturbation approach.{"} In order to correctly compute the complex characteristic impedance under leakage conditions, the new theory requires to carefully {"}extract out{"} the surface-wave or parallel plate-wave poles on the complex k-plane. In obvious difference to this, it is well known that the poles must be {"}included{"} for a correct solution of the complex propagation constant of the leaky line. Incidentally, unlike the conventional methods, the new theory derives the complex characteristic impedance together with the solution of the phase and attenuation constants, in a single unified procedure. This avoids additional efforts in computational or analytical/formulational complexity. Results for selected cases of interest are presented, which demonstrate the validity and simplicity/elegance of the new theory.",
keywords = "Characteristic impedance, Leaky waves, Planar transmission line, Slotline, Stripline",
author = "Nirod Das",
year = "2000",
doi = "10.1109/22.848493",
language = "English (US)",
volume = "48",
pages = "1108--1117",
journal = "IEEE Transactions on Microwave Theory and Techniques",
issn = "0018-9480",
publisher = "Institute of Electrical and Electronics Engineers Inc.",
number = "7 PART 1",

}

TY - JOUR

T1 - A New Theory of the Characteristic Impedance of General Printed Transmission Lines Applicable when Power Leakage Exists

AU - Das, Nirod

PY - 2000

Y1 - 2000

N2 - Conventional definitions of the characteristic impedance, such as the voltage-current, power-current, and power-voltage methods, which have been commonly used for standard nonleaky transmission lines, become invalid when power leakage occurs. In this paper, we present a new theory of the characteristic impedance for printed transmission lines, applicable under the general conditions with or without power leakage. The theory is founded on dual field and circuit theories of transmission lines, formulated in the spectral domain, and uses a new approach called "the wavenumber perturbation approach." In order to correctly compute the complex characteristic impedance under leakage conditions, the new theory requires to carefully "extract out" the surface-wave or parallel plate-wave poles on the complex k-plane. In obvious difference to this, it is well known that the poles must be "included" for a correct solution of the complex propagation constant of the leaky line. Incidentally, unlike the conventional methods, the new theory derives the complex characteristic impedance together with the solution of the phase and attenuation constants, in a single unified procedure. This avoids additional efforts in computational or analytical/formulational complexity. Results for selected cases of interest are presented, which demonstrate the validity and simplicity/elegance of the new theory.

AB - Conventional definitions of the characteristic impedance, such as the voltage-current, power-current, and power-voltage methods, which have been commonly used for standard nonleaky transmission lines, become invalid when power leakage occurs. In this paper, we present a new theory of the characteristic impedance for printed transmission lines, applicable under the general conditions with or without power leakage. The theory is founded on dual field and circuit theories of transmission lines, formulated in the spectral domain, and uses a new approach called "the wavenumber perturbation approach." In order to correctly compute the complex characteristic impedance under leakage conditions, the new theory requires to carefully "extract out" the surface-wave or parallel plate-wave poles on the complex k-plane. In obvious difference to this, it is well known that the poles must be "included" for a correct solution of the complex propagation constant of the leaky line. Incidentally, unlike the conventional methods, the new theory derives the complex characteristic impedance together with the solution of the phase and attenuation constants, in a single unified procedure. This avoids additional efforts in computational or analytical/formulational complexity. Results for selected cases of interest are presented, which demonstrate the validity and simplicity/elegance of the new theory.

KW - Characteristic impedance

KW - Leaky waves

KW - Planar transmission line

KW - Slotline

KW - Stripline

UR - http://www.scopus.com/inward/record.url?scp=0034224432&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0034224432&partnerID=8YFLogxK

U2 - 10.1109/22.848493

DO - 10.1109/22.848493

M3 - Article

VL - 48

SP - 1108

EP - 1117

JO - IEEE Transactions on Microwave Theory and Techniques

JF - IEEE Transactions on Microwave Theory and Techniques

SN - 0018-9480

IS - 7 PART 1

ER -