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A 100 Ω transmission line has an effective dielectric constant of 1.65. Find the shortest open-circuited length of this line that appears at its input as a capacitor of 5 pF at 2.5 GHz. Repeat for an inductance of 5 nH.

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The shortest open-circuited length of the transmission line that appears as a capacitor of 5 pF at 2.5 GHz is approximately 0.0827 meters. The inductance of the line for an inductance of 5 nH is approximately 4.91 nH.

Step-by-step explanation:

To find the shortest open-circuited length of the transmission line that appears as a capacitor of 5 pF at 2.5 GHz, we can use the formula:

C = (ε₀εᵣL)/open-length

Given that the effective dielectric constant (εᵣ) is 1.65 and the capacitance (C) is 5 pF, we can rearrange the formula to solve for the open-length:

open-length = (ε₀εᵣL)/C

Plugging in the values, the open-length will be:

open-length = (8.854 × 10⁻¹² × 1.65 × (2.5 × 10⁹)⁻² × 5 × 10⁻¹²)/5 × 10⁻¹²

Simplifying this equation gives us:

open-length ≈ 0.0827 meters

For the inductance of 5 nH, we can use the formula:

L = (open-length)² / (ε₀εᵣC)

Using the same values as before, the inductance will be:

L = (0.0827)² / (8.854 × 10⁻¹² × 1.65 × (5 × 10⁻¹²)⁻¹²)

Simplifying this equation gives us:

L ≈ 4.91 nH

User Elad BA
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