## 021/100 Distributed Inductance and Capacitance

100 ADS Design Examples Based on the Textbook: RF and Microwave Circuit Design

November 2019

Michael Benker

**Example 2.11-2D: Convert the lumped element capacitors and inductors to distributed elements.**

This is the schematic that needs to be changed into distributed element microstrip lines:

The following formulas are needed to calculate the inductive and capacitive line lengths to simulate this schematic using microstrip lines.

**Inductive line length: (frequency)*(wavelength)*(Inductance)/(impedance of line)**

**Capacitive line length: (frequency)*(wavelength)*(Capacitance)*(impedance of line)**

In order to know what at which frequency the inductance or capacitance are calculated, let’s run the simulation of the above circuit:

This circuit is centered at 10 GHz, since the circuit behaves as a terminated open-circuited transmission line with an open-parallel resonance at 180 degrees, or twice the length of a quarter wave line.

The above circuit is then modeled as follows:

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