#### When coupled **lines** are driven in the common mode (same magnitude, same polarity), the even mode **impedance** is the **impedance** seen by a signal travelling on one **transmission** **line** in the pair. A similar definition applies when the **lines** are driven in differential mode (same magnitude, same polarity):. L is the length of the **transmission** **line** or the depth of the pore. The two interfaces "A" and "B" are represented by **impedances** Z A (x = 0) on the outer surface of the pore and Z B (x = L) on the base electrode at the end of the pore. Along the pore, the **transmission** **line** is represented by repeating **impedance** elements. perfect conductivity with no loss Example: Air - **Line** Draw the **transmission line model** and Find Cʼ and Lʼ; Assume perfect conductor and perfect dielectric materials are used! ( , ) 0.2cos(2 700 10 20 5) ( , ) 10cos(2 700 10 20 5) 6 6 = ⋅ ⋅ − + = ⋅ ⋅ − + I z t z V z t z π π Perfect Conductor!.

**impedance**.

**Transmission line model**.

**Transmission line**loss. Propagation constant. Skin depth. Group delay. Below are some specific types of

**transmission lines**that we have.

**Transmission Line**Terminated with Zo For reflection, a

**transmission line**terminated in Zo behaves like an infinitely long

**transmission line**Zs = Zo Zo V refl = 0!. Notes. The length of the

**line**must be expressed in one of the following two ways: the

**Transmission**Delay is specified directly (eg, TD=10ns) a value for the Frequency is specified, together with a value for the Normalised Length.; If a value for Frequency is specified but a value for the Normalised Length is omitted, then 0.25 is assumed (that is, the frequency is assumed.