OrCAD PCB Layout
ECE457 Senior Design
Michael Benker
December 2019
ECE457 Senior Design
Michael Benker
November 2019
OrCAD Schematic
The schematic below was made using OrCAD Capture CIS. A PCB design is soon to follow. This schematic was made partially as a visual demonstration and therefore features components that will not be part of the pcb, such as buttons, which will be panel-mounted.
ECE435 RF/Microwave Engineering, Professor Dr. Li
Michael Benker
November 2019
Microstrip Coupled Line Bandpass Filter
Final Results:
100 ADS Design Examples Based on the Textbook: RF and Microwave Circuit Design
November 2019
Michael Benker
Example 4.2-3: Analyze the parallel resonator that is attached to a 50 Ohm source and load as shown.
This problem is specifically asking to define the Q factor related to this circuit. The Q factor is a ratio of energy stored (by an inductor or capacitor) to the power dissipated in a resistor. The Q factor varies with frequency since the effect of a capacitor or inductor also vary with frequency. For a series resonant circuit, the “unloaded” Q factor is defined by the following function: Qu = X / R = 1/(wRC) = wL/R
The unloaded Q factor of a parallel resonant circuit: Qu = R / X = R/(wL) = wRC
Overall, the Q factor is a measure of loss in the resonant circuit. A higher Q corresponds to lower loss, while a lower Q indicated higher loss. An “unloaded” Q factor means that the resonator is not connected to a source or load. The above circuit can no longer apply the “unloaded” Q factor formulas due to the presence of a source and a load. There are two further Q factor formulas that need to be considered: loaded Q factor and external Q factor. The loaded Q factor includes the source resistance and load resistance with the resistance of the circuit. The external Q factor refers to only the source resistance and load resistance together.
For the above circuit, the loaded Q factor for the parallel resonator is defined as:
Loaded Q = (Rs + R + Rl)/(wL) = (Source resistance + R + load resistance) / (wL)
The external Q factor for the source resistance and load resistance is:
External Q = (Rs + Rl)/(wL) = (Source resistance + load resistance)/(wL)
The relationship between the different types of Q factors are:
1/(Loaded Q) = 1/(External Q) + 1/(Unloaded Q)
100 ADS Design Examples Based on the Textbook: RF and Microwave Circuit Design
November 2019
Michael Benker
Example 4.2-2: Analyze a rearrangement of the RLC components into a parallel configuration.
As observable by the following figures, the resonant frequency and impedance value remain the same for the parallel RLC circuit. What may be understood by this is that the reactance of the inductor cancels out the reactance of the capacitor at this frequency of 505 MHz.
The input admittance of a parallel resonant circuit is: Y = (1/R) + jwC + (1/jwL).
The angular frequency, w = 2*pi*f = 1 / (sqrt(L*C)).
100 ADS Design Examples Based on the Textbook: RF and Microwave Circuit Design
November 2019
Michael Benker
Example 4.2-1: Analyze a one port series RLC circuit with R = 10 Ohms, L = 10 nH and C = 10 pF.
According to the following results, the input impedance at resonance is 10 Ohms, which is the value of the resistor.
The input impedance of an RLC series circuit is modeled by the following formula, a rather basic expression: Z = R + jwL + 1/(jwC)
The power delivered to the resonator is: P = |I|^2 * Z / 2.
100 ADS Design Examples Based on the Textbook: RF and Microwave Circuit Design
November 2019
Michael Benker
Example 2.11-3: Calculate the physical line length of the λ/4 sections of 80 Ω and 20 Ω microstrip lines at a frequency of 2 GHz. Create a schematic of a distributed bias feed network.
A high impedance microstrip line of λ/4 can be used to replace the lumped inductor from problem 022/100 Example 2.11-2E. Likewise a quarter wave impedance line of a low impedance can replace the lumped shunt capacitor. The 80 Ohm and 20 Ohm transmission lines can be made using LineCalc at 2 GHz. The taper, tee and end-effect element are used to simulate the circuit most correctly and to remove discontinuities between the models.
The return loss null occurs at 1.84 GHz, indicating that the system could be optimized better to adjust center frequency. The high impedance line length is now adjusted to center the frequency to 2 GHz:
100 ADS Design Examples Based on the Textbook: RF and Microwave Circuit Design
November 2019
Michael Benker
Example 2.11-2E: Design a lumped element biased feed network.
Bias feed networks are an important application of high impedance and low impedance microstrip transmission lines. The voltage bias may be needed for a device that is connected to the microstrip line, such as a transistor, MMIC amplifier or diode. The inductor in the circuit below is used as an “RF Choke”, which is used in tandem with a shunt or bypass capacitor for a “bias decoupling network.” Lumped elements are typically used for frequencies below 200 MHz.
The following is a typical bias feed network, followed by a simulation:
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:
100 ADS Design Examples Based on the Textbook: RF and Microwave Circuit Design
November 2019
Michael Benker
Example 2.11-2C: Calculate the input impedance of a quarter wave open-circuited microstrip transmission line using termination with end effects.
An open circuit microstrip line generates a capacitive end effect due to radiation. This radiation is observable in the results from the following simulation. Note that the impedance at 180 degrees is more capacitive than was the open circuit transmission line with out any termination.
100 ADS Design Examples Based on the Textbook: RF and Microwave Circuit Design
November 2019
Michael Benker
Example 2.11-2B: Calculate the input impedance of a quarter wave open-circuited microstrip transmission line for a given length of time.
The reactance of a lossless open circuit transmission line can be modeled as being equal to the characteristic impedance multiplied by the cotangent of the electrical length of the transmission line in degrees.
X = Z * cot(Θ)
To construct this circuit, a termination of 1 MOhms is used to simulate an open circuit. As the electrical length in degrees varies with frequency (the wavelength), a static electrical length of a transmission line varied over many frequencies will suffice to demonstrate the reactance of a varying electrical length transmission line. The following circuit was created with a transmission line optimized for 10 GHz, similar to the Short-circuited Transmission Line:
The results above are consistent with the theoretical model of an open circuit transmission line being modeled by a cotangent relationship. At the optimized frequency (at which the transmission line length is quarter-wave) it can be observed that the impedance of the line is measured to be zero. At a half-wave length and other multiples of a half wave length, the transmission line generates high levels of resonance.
100 ADS Design Examples Based on the Textbook: RF and Microwave Circuit Design
November 2019
Michael Benker
Example 2.11-2A: Calculate the input impedance of a short-circuited microstrip transmission line for a given electrical length of the line.
This circuit was built with a quarter-wave microstrip synthesized for 10 GHz with given substrate (conductivity of gold) using the LineCalc tool.
The following results conclude that a short-circuited quarter-wave transmission line has high impedance, similar to an open circuit. A short circuited transmission line that is not a quarter-wave transmission line will not have high impedance as demonstrated by frequencies far outside of the range of optimization (10 GHz). This phenomena is is consistent with electromagnetic theory on transmission lines.
Theoretical relationship between transmission line length (short-circuited) and it’s imaginary impedance component:
ECE457 Senior Design
November 2019
Michael Benker
Random Signal Analyzer
The following MATLAB program is designed to create a random signal and analyze statistical properties. The applications for this are a current senior design project and the code may eventually be implemented in a project that involves a sound level analysis program on a microcontroller.
ECE435 – RF/Microwave Engineering, Professor Dr. Yifei Li
November 2019
Michael Benker
Rat Race Coupler ADS Simulation
ECE471 – Communication Theory, Professor Dr. Paul Gendron
November 2019
Michael Benker
Frequency Shift Keying
The following MATLAB code simulates Frequency Shift Keying, an essential part of Communications.
The real MVP
LikeLike
ECE435 – RF/Microwave Engineering, Professor Dr. Yifei Li
October 2019
Michael Benker
Directional Coupler ADS Simulation
ECE457 – Senior Design Project, Professor Dr. Fortier
October 2019
Michael Benker
MATLAB Data Analysis
The following code was one component of my current Senior Design Project assignment, which will involve the creation of a device known as the “Audio Awareness Enabler.” More information relating to this project is sure to follow in the future. For now, let us take a look at the following MATLAB code, which takes excel files of data and calculates the averages and standard deviations and then plots a Gaussian normal plot. Soon, this code will be modified to be able to determine whether a set of data will fall into the “ambient” range or one of the three interrupt levels. It will also eventually seek to create a formula that will determine whether a set of data is in the interrupt zone based on the ambient level.
See the pdf file: ece457p9v002
Data at one location:
Next location:
ECE435 – RF/Microwave Engineering, Professor Dr. Yifei Li
October 2019
Michael Benker
ADS Coupler Momentum Simulation
Build the ADS circuit.
Run the momentum simulation and set parameters such as substrate.
This is a momentum simulation. Let’s see if we can optimize this.
Export the part to be used as a component in the workspace library in ADS.
Now run an ADS simulation using the exported component, which uses a database of simulated results.
If you step into the component, you will see component features.
Now, tune the parameters to begin optimization.
ECE435 – RF/Microwave Engineering, Professor Dr. Yifei Li
October 2019
Michael Benker
ADS Momentum Simulation
ECE471 – Communication Theory, Professor Dr. Paul Gendron
October 2019
Michael Benker
Voltage Control Oscillator MATLAB Simulation, Integral to Costa’s Receiver
ECE435 – RF/Microwave Engineering, Professor Dr. Yifei Li
October 2019
Michael Benker
ADS Momentum Simulation
ECE435 – RF/Microwave Engineering, Professor Dr. Yifei Li
October 2019
Michael Benker
Project 4 – Quadrature Hybrid Coupler
Presentation: Project4_presentation
ECE435 – RF/Microwave Engineering, Professor Dr. Yifei Li
September 2019
Michael Benker
Project 1 – Smith Chart Impedance Matching
Presentation: proj1_presentation
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.
This lab demonstrates the rejection of common-mode noise while amplifying differential-mode signals. This is the final circuit in Multisim.
The circuit is comprised of one oscillator, one inverting amplifier, two weighted summers and one differential amplifier.
This is a screen capture of the noise disconnected.
ECE336 – Electromagnetic Theory II, Professor Dr. Yifei Li
April 2019
Michael Benker
20 GHz RF Amplifier Design – ADS
This is a 20 GHz amplifier circuit, made using smith chart impedance matching in ADS. This circuit is one of the first times I have used this powerful software. Glad to be putting my emag theory to work to build something real. The report should be helpful for me to jog my memory to do it again. With the notes I have, a similar circuit should be possible.
For the impedance matching, I considered using an inductor, though using only caps and t-lines, the result seemed to be cleaner.
See the following for the full report:
Tuong 9:39 pm on December 2, 2019 Permalink |
Hi, What is function of this circuit?
LikeLike
mbenkerumass 7:21 am on December 3, 2019 Permalink |
Thanks for the comment! This device is proposed to adjust the volume output between an audio source and headphones relative to the sound level in the surrounding environment. Possible applications could be in noise cancelling technology, for instance.
LikeLike
Tuong 10:46 am on December 3, 2019 Permalink |
Hi Michael. Thanks for reply. Interesting! May be you can show the real board when available, plz. I just curious.
LikeLike