Agilent Technologies 8510-58 manual Linear delay Actual delay = Fco/f2, Offset Z0

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The convention for definition of offset delay in waveguide requires entry of the delay assuming no dispersion. For waveguide transmission line, the Agilent 8510 calculates the effects of dispersion as a function of frequency as follows:

Linear delay

Actual delay =

1 - (fco/f)2

For the WR-62 calibration kit, offset delay is zero for the “thru” (std #4) and the “load” (std #3). To find the offset delay of the 1/8 λ and 3/8 λ offset shorts, precise offset length measurements are nec- essary. For the 1/8 λ offset short, l = 3.24605 mm, εr = 1.000649, c = 2.997925 x 108m/s.

Delay = (3.24605 x 10 -3m) (√1.000649) = 10.8309 pS 2.997925 x 108 m/s

fco = lower cutoff frequency f = measurement frequency

Note

To assure accurate definition of offset delay, a physical measurement of offset length is recom- mended.

The actual length of offset shorts will vary by man- ufacturer. For example, the physical length of a

1/8 λ offset depends on the center frequency chosen. In waveguide this may correspond to the arith- metic or geometric mean frequency. The arithmetic mean frequency is simply (F1 + F2)/2, where F1 and F2 are minimum and maximum operating frequen- cies of the waveguide type. The geometric mean frequency is calculated as the square root of F1 x F2. The corresponding (λg) is then calculated from the mean frequency and the cutoff frequency of the waveguide type. Fractional wavelength offsets are then specified with respect to this wavelength.

For the 3/8 λ offset short, I = 9.7377 mm, εr = 1.000649, c = 2.997925 x 108 m/s.

Delay = (9.7377 x 10-3m) (√1.000649) = 32.4925 pS 2.997925 x 108 m/s

Offset Z0

Offset Z0 is the characteristic impedance within the offset length. For coaxial type offset standards, specify the real (resistive) part of the characteris- tic impedance in the transmission media. The char- acteristic impedance in lossless coaxial transmission media can be calculated from its physical geometry as follows.

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Contents Product Note 8510-5B Table of contents Introduction Measurement errorsMeasurement calibration Calibration kit Class assignment Standard definitionStandard definitions table Standard class assignments Select standards Modification procedureStandard definition models Define standardsStandard type Standard numberOpen circuit capacitance C0 , C1 , C2 and C3 ΠfZ ΠfXShort circuit inductance L0 , L1, L2 and L3 ∆∅radians = 2πf ∆lengthDelay seconds = Offset delayFixed or sliding Terminal impedanceOffset Z0 Linear delay Actual delay = Fco/f21GHz = Offset loss1GHz c Z0 10 log10e εrLower/minimum frequency Fupper = 2 x Flower Upper/maximum frequencyCoax or waveguide ∅radians =Standard labels Assign classesStandard Classes Forward transmission match and thru S11 A,B,C and S22 A,B,CReverse transmission match and thru IsolationTRL Reflect TRL ThruTRL Line TRM ThruTRL options Standard Class labelsCalibration kit label Verify performance Enter standards/classesModification examples User modified cal kits and Agilent 8510 specificationsModeling a thru adapter Modeling an arbitrary impedance standardDisk procedure Appendix a Calibration kit entry procedureTo load calibration kits from disk into Agilent To store calibration kits from the Agilent 8510 onto a diskFront panel procedure P-band waveguide example Pshort Mm coaxial connector interface Appendix B Dimensional considerations in coaxial connectorsType-N coaxial connector interface Female type-N Mm Coaxial connector Type-N coaxial connector interfacePage Equation Appendix C Cal coefficients modelTheir first order approximations, R is small and G=0, are Then Online assistance Phone or Fax United States
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