RF Designer can be purchased from Google Play

Image

RF Designer - Components (Physical Transmission Lines)

Full listing and description of components that can be placed in an RF Designer schematic.
rftools
Site Admin
Posts: 13
Joined: Thu May 22, 2014 12:36 pm

RF Designer - Components (Physical Transmission Lines)

Postby rftools » Wed Jan 07, 2015 5:57 am

Physical Transmission Line Elements

TLINP - Physical Transmission Line

Image






NameDescriptionUnitsDefault Value
ZImpedanceResistance50 ohms
LPhysical lengthDimensions1000 mil
εeffEffective dielectric constantUnitless1.0
AAttenuation per unit lengthdecibels0 dB/mil
F0Frequency for attenuation factorFrequency1000 MHz


Model for a physical and lossy transmission line. Electrical length of the transmission line is calculated at each simulated frequency using the user supplied physical length (L) and the effective dielectric constant (Eeff).
Loss per unit length is determined by the user supplied loss (A) and frequency for scaling (F0). If F0 is set to 0, then the loss per unit length is constant regardless of simulation frequency. Otherwise, the loss is scaled by the square root of the ratio of the simulation frequency and F0 (sqrt(f/F0)).

TLPOC - Physical Open Circuited Transmission Line

Image






NameDescriptionUnitsDefault Value
ZImpedanceResistance50 ohms
LPhysical lengthDimensions1000 mil
εeffEffective dielectric constantUnitless1.0
AAttenuation per unit lengthdecibels0 dB/mil
F0Frequency for attenuation factorFrequency1000 MHz


Model for a physical and lossy open circuited transmission line. Electrical length of the transmission line is calculated at each simulated frequency using the user supplied physical length (L) and the effective dielectric constant (Eeff).
Loss per unit length is determined by the user supplied loss (A) and frequency for scaling (F0). If F0 is set to 0, then the loss per unit length is constant regardless of simulation frequency. Otherwise, the loss is scaled by the square root of the ratio of the simulation frequency and F0 (sqrt(f/F0)).

TLPSC - Physical Short Circuited Transmission Line

Image






NameDescriptionUnitsDefault Value
ZImpedanceResistance50 ohms
LPhysical lengthDimensions1000 mil
εeffEffective dielectric constantUnitless1.0
AAttenuation per unit lengthdecibels0 dB/mil
F0Frequency for attenuation factorFrequency1000 MHz


Model for a physical and lossy short circuited transmission line. Electrical length of the transmission line is calculated at each simulated frequency using the user supplied physical length (L) and the effective dielectric constant (Eeff).
Loss per unit length is determined by the user supplied loss (A) and frequency for scaling (F0). If F0 is set to 0, then the loss per unit length is constant regardless of simulation frequency. Otherwise, the loss is scaled by the square root of the ratio of the simulation frequency and F0 (sqrt(f/F0)).

TLINP4 - Physical 4 Node Transmission Line

Image






NameDescriptionUnitsDefault Value
ZImpedanceResistance50 ohms
LPhysical lengthDimensions1000 mil
εeffEffective dielectric constantUnitless1.0
AAttenuation per unit lengthdecibels0 dB/mil
F0Frequency for attenuation factorFrequency1000 MHz


Model for a physical and lossy transmission line with the ground terminals left open and available as ports in the schematic. Electrical length of the transmission line is calculated at each simulated frequency using the user supplied physical length (L) and the effective dielectric constant (Eeff).
Loss per unit length is determined by the user supplied loss (A) and frequency for scaling (F0). If F0 is set to 0, then the loss per unit length is constant regardless of simulation frequency. Otherwise, the loss is scaled by the square root of the ratio of the simulation frequency and F0 (sqrt(f/F0)).

CLINP - Physical Coupled Transmission Line

Image








NameDescriptionUnitsDefault Value
ZoeEven-mode impedanceResistance69 ohms
ZooOdd-mode impedanceResistance36 ohms
LPhysical lengthDimensions1000 mil
εeffEEven-mode effective dielectric constantUnitless1.0
εeffOOdd-mode effective dielectric constantUnitless1.0
AEEven-mode attenuation per unit lengthdecibels0 dB/mil
AOOdd-mode attenuation per unit lengthdecibels0 dB/mil


Model for a pair of lossy symmetric coupled transmission lines. Length is specified as a physical length(L). Coupling is determined by the even and odd mode impedances (Zoe and Zoo), effective dielectrics (EeffE and EeffO), and attenuation per unit length(AE and AO) over the specified physical length (L).

Given a desired coupling C in decibels, Zoe = Zo * ((1 + k) / (1 - k)) where k = power(10.0, -C/20.0). Zoo can the be found by solving Zoo = Zo * ((1 - k) / (1 + k))

Example: Find Zoe and Zoo for a 10 dB coupler in a 50 ohm system.
First calculate k as k = power(10.0, -10/20) = 0.316
Zoe is found as Zoe = Zo * ((1 + .316) / (1 - .316)) = 96.2 ohms
Zoo is found as Zoo = Zo * ((1 - .316) / (1 + .316)) = 26 ohms

Return to “Component Catalog”

Who is online

Users browsing this forum: No registered users and 1 guest