# ECE 488

## Microwave Engineering II: Active Circuit Design

Spring

Required Course:
No

### Course Level

Undergraduate

### Units

3

### Prerequisite(s)

ECE 486

### Course Texts

Steer, Michael. *Microwave and RF Design: A System Approach*. 2nd ed. (rev.). SciTech Publishing, 2013.

Suggested reading:

- Gonzalez, Guillermo.
*Microwave Transistors: Analysis and Design*. 2nd ed. Pearson, 1996. - Maas, Stephen.
*Nonlinear Microwave Circuits*. Wiley-IEEE Press, 1996.

### Schedule

150 minutes lecture per week

### Course Description

Planar active microwave circuits, diode and transistor characteristics, mixers, amps, oscillators, and frequency multipliers. Students will design circuits with CAD tools, fabricate in clean room, and measure performance in the lab.

### Learning Outcomes

By the end of this course the student will be able to:

- Understand various modulation schemes, the basics of wireless transmitters and receivers, and the basics of antennas and the wireless link
- Understand fundamentals of RF systems
- Design lumped element matching networks
- Design single- and double-stub matching networks for various loads
- Apply single- or double-stub matching network designs for circuits in microstrip form
- Create all active circuit designs in microstrip form
- Identify the diode equation, the small signal model and equivalent circuit
- Explain the role and operation of the depletion and diffusion capacitance
- Describe the operation of a Schottky barrier diode
- Explain how diodes can be used for RF/microwave signal detection and mixing
- Identify and design various types of microwave mixers, as well as parameters used for evaluating their performance
- Describe the characteristics of bipolar and FET microwave transistors
- Identify the small-signal electric models of microwave transistors
- Explain how to measure a transistor's s-parameters
- Apply signal flow graphs to evaluate scattering and other parameters of microwave circuits
- Identify the different power gain expressions of microwave amplifier circuits, and calculate from s-parameters
- Calculate the input and output VSWR of a microwave amplifier
- Determine the stability of an amplifier from the transistor, matching networks and terminations
- Explain when a two-port network is unilateral
- Outline the procedure for drawing the constant G-circles for unconditionally stable and potentially unstable cases
- Identify and evaluate the unilateral figure of merit
- Design a microwave amplifier for a specific operating power gain and stability
- Plot power gain circles for a two-port network
- Design a microwave amplifier for a specific power gain, input/output VSWR, and with good ac performance
- Design a DC bias network for a microwave amplifier
- Design various types of microwave amplifiers: low-noise, broadband, feedback and two-stage
- Distinguish between class A, B and C microwave amplifiers
- Evaluate the dynamic range of a microwave amplifier
- Describe the operation of one-port negative resistance oscillators
- Apply the Nyquist test to determine conditions of unstable operations of a given circuit
- Design a two-port negative resistor microwave oscillator
- Explain the operation of varactor frequency multiplier
- Determine which active microwave circuit to use depending on the application
- Identify potential limitations in the circuit fabrication process
- Explain how different fabrication steps can affect active circuit performance, and explain how each affects it
- Perform microwave measurements for the active circuit of the design
- Explain differences between simulated and measured data of active microwave

### Course Topics

- Introduction to modulation techniques
- Digital modulation
- Receivers, modulators and demodulators
- Antennas
- Radio link
- Radio systems
- Cellular radio: 1G-3G
- Beyond 3G and radar
- Matching networks
- Microstrip matching networks
- Microwave transistors
- Scattering parameters and signal flow graphs
- Power gain expressions and VSWR calculations
- Stability considerations
- Constant gain circles
- Simultaneous conjugate match
- Operating and available power gain circles
- VSWR circles and DC bias networks
- Noise in microwave systems
- Constant noise figure circles
- Design of low-noise amplifier
- Amplifier designs: broad-band, high-power and two-stage
- Oscillation conditions

### Relationship to Student Outcomes

ECE 488 contributes directly to the following specific electrical and computer engineering student outcomes of the ECE department:

- Ability to apply knowledge of mathematics, science and engineering (high)
- Ability to design and conduct experiments, as well as to analyze and interpret data (medium)
- Ability to design a system, component or process to meet desired needs within realistic constraints, such as economic, environmental, social, political, ethical, health and safety, manufacturability and sustainability (low)
- Ability to function on multidisciplinary teams (low)
- Ability to identify, formulate and solve engineering problems (medium)
- Ability to communicate effectively (medium)
- Ability to use the techniques, skills and modern engineering tools necessary for engineering practice (high)

### Syllabus Prepared By

Hao Xin, 04/14/16