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

Michael Benker

Example 2.9-1: Consider the model of a one inch and a three inch length of the waveguide as used in an X Band satellite transmission system. Display the insertion loss of the waveguides from 4 to 8 GHz.

377 Ohms simulates free space

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

October 2019

Michael Benker

Example 2.4-1: For series RLC elements, measure the reflection coefficients and VSWR from 100 to 1000 MHz in 100 MHz steps.

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

October 2019

Michael Benker

Example 1.5-2B: Calculate the Q factor versus frequency for the modified physical model of an 8.2 pF multilayer chip capacitor.

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

Michael Benker

Example 1.5-2A: Calculate the Q factor versus frequency for the physical model of an 8.2 pF multilayer chip capacitor.

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

Michael Benker

Example 1.5-1 Consider the design of a single layer capacitor from a dielectric that is 0.010 inches thick and has a dielectric constant of three. Each plate is cut to 0.040 inches square. Calculate the capacitor value and its Q factor.

Capacitance formed by a dielectric material between two parallel plate conductors:

C = (N-1)(KAεr/t)(FF) pF

A: plate area

εr: relative dielectric constant

t: separation

K: unit conversion factor; 0.885 for cm, 0.225 for inches

FF: fringing factor; 1.2 when mounted on microstrip

N: number of parallel plates

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

Michael Benker

Example 1.4-6 Design a 550 nH inductor using the Carbonyl W core of size T30/ Determine the number of turns and model the inductor in ADS.

Number of turns calculation: N = sqrt(L/A) = sqrt(55nH/2.5) = 14.8

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

Michael Benker

Example 1.4-4 Calculate the Q factor of the air core inductor used in previous example 1.4-2.

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

Michael Benker

Example 1.4-3 Create a simple RLC network that gives an equivalent impedance response similar to previous example 1.4-2.

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

Michael Benker

Example 1.4-2 Calculate and plot the input impedance of an air core inductor.

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

Michael Benker

Example 1.3-1B: Plot the impedance of a 5 Ω leaded resistor in ADS over a frequency range of 0 to 2 GHz.

This indicates a resonance at 500 MHz. This is due to the parasitic iductance and capacitance that exists on a real resistor. The resistor behaves as a combination of series parasitic inductance and resistance, in parallel with a parasitic capacitance.

The impedance of an inductor is reduced as the frequency increases, while the impedance of a capacitor increases as the frequency increases. The intersection frequency of these two patters meet is the resonant frequency.

The resonance frequency can be found from equating XL and XC. The formula is:

Resonant frequency fR = 1/(2*pi*sqrt(LC))

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

Michael Benker

Example 1.3-1A Plot the impedance of a 50 Ω ideal resistor in ADS over a frequency range of 0 to 2 GHz.

Thereby noting that an ideal resistor maintains constant impedance with respect to frequency.

You were here and you read it, so don’t forget it.

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

Michael Benker

Example 1.2-4 Calculate the inductance of the 3 inch Ribbon at 60 Hz, 500 MHz, and 1 GHz. Make the ribbon 100 mils wide and 2 mils thick.

The flat ribbon inductance is calculated with the following equation:

L = K*l*[ ln((2*l)/(W+T))+0.223*(W+T)/l + 0.5 ] nH

l: length of the wire

K: 2 for dimensions in cm and K=5.08 for dimensions in inches

W: the width of the conductor

T: the thickness of conductor

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

Michael Benker

Example 1.2-1: Calculate the reactance and inductance of a three inch length of AWG #28 copper wire in free space at 60 Hz, 500 MHz, and 1 GHz.

> The increase in reactance with respect to frequency represents the skin effect property, in which, as the frequency increases, the current density begins to be concentrated on the surface of a conductor.

I found this book has a number of interesting problems that I would like to go through by myself to get some experience with ADS. I may change my mind, however I intend on posting my solutions to my blog (here) as I go through them, if I do. Stay tuned.

## Electrical Engineering Students at University of Massachusetts Dartmouth