1 Overview of Electrical Engineering Lecture 8A: Introduction to Engineering

Lecture 1 2 Foundations of Electrical Engineering Electrophysics Electrophysics Information (Communications) Theory Information (Communications) Theory Digital Logic Digital Logic

Lecture 1 3 Foundations of Electrical Engineering Electrophysics : Electrophysics : Fundamental theories of physics and important special cases. Fundamental theories of physics and important special cases. Phenomenological/behavioral models for situations where the rigorous physical theories are too difficult to apply. Phenomenological/behavioral models for situations where the rigorous physical theories are too difficult to apply.

Lecture 1 4 Hierarchy of Physics Theories Involved in the Study of Electrical Engineering Quantum electrodynamics Quantum electrodynamics Quantum mechanics Quantum mechanics Schrödinger equation Schrödinger equation Classical electromagnetics Classical electromagnetics Electrostatics Electrostatics Electrodynamics Electrodynamics Circuit theory Circuit theory Geometric optics Geometric optics

Lecture 1 5 Maxwell’s Equations

Lecture 1 6 Information Theory Originally developed by Claude Shannon of Bell Labs in the 1940s. Originally developed by Claude Shannon of Bell Labs in the 1940s. Information is defined as a symbol that is uncertain at the receiver. Information is defined as a symbol that is uncertain at the receiver. The fundamental quantity in information theory is channel capacity – the maximum rate that information can be exchanged between a transmitter and a receiver. The fundamental quantity in information theory is channel capacity – the maximum rate that information can be exchanged between a transmitter and a receiver. The material in this slide and the next has been adapted from material from

Lecture 1 7 Information Theory Defines relationships between elements of a communications system. For example, Defines relationships between elements of a communications system. For example, Power at the signal source Power at the signal source Bandwidth of the system Bandwidth of the system Noise Noise Interference Interference Mathematically describes the principals of data compression. Mathematically describes the principals of data compression.

Lecture 1 8 Exercise: What is Information? Message with redundancy: Message with redundancy: “Many students are likely to fail that exam.” “Many students are likely to fail that exam.” Message coded with less redundancy: Message coded with less redundancy: “Mny stdnts are lkly to fail tht exm.” “Mny stdnts are lkly to fail tht exm.” Claude Shannon, founder of Information Theory

Lecture 1 9 Digital Logic Based on logic gates, truth tables, and combinational and sequential logic circuit design Based on logic gates, truth tables, and combinational and sequential logic circuit design Uses Boolean algebra and Karnaugh maps to develop Uses Boolean algebra and Karnaugh maps to developminimized logic circuits. logic circuits.

Lecture 1 10 EE Subdisciplines Power Systems Power Systems Electromagnetics Electromagnetics Solid State Solid State Communication/Signal Processing Communication/Signal Processing Controls Controls Analog/Digital Design Analog/Digital Design

Lecture 1 11 Power Systems Generation of electrical energy Generation of electrical energy Storage of electrical energy Storage of electrical energy Distribution of electrical energy Distribution of electrical energy Rotating machinery-generators, motors Rotating machinery-generators, motors

Lecture 1 12 Electromagnetics Propagation of electromagnetic energy Propagation of electromagnetic energy Antennas Antennas Very high frequency signals Very high frequency signals Fiber optics Fiber optics

Lecture 1 13 Solid State Devices Devices Transistors Transistors Diodes (LED’s, Laser diodes) Diodes (LED’s, Laser diodes) Photodetectors Photodetectors Miniaturization of electrical devices Miniaturization of electrical devices Integration of many devices on a single chip Integration of many devices on a single chip

Lecture 1 14 Communications/Signal Proc. Transmission of information electrically and optically Transmission of information electrically and optically Modification of signals Modification of signals enhancement enhancement compression compression noise reduction noise reduction filtering filtering

Lecture 1 15 Controls Changing system inputs to obtain desired outputs Changing system inputs to obtain desired outputs Feedback Feedback Stability Stability

Lecture 1 16 Digital Design Digital (ones and zeros) signals and hardware Digital (ones and zeros) signals and hardware Computer architectures Computer architectures Embedded computer systems Embedded computer systems Microprocessors Microprocessors Microcontrollers Microcontrollers DSP chips DSP chips Programmable logic devices (PLDs) Programmable logic devices (PLDs)

Lecture 1 17 Case Study: C/Ku Band Earthstation Antennas ATCi Corporate Headquarters 450 North McKemy Chandler, AZ USA Simulsat Parabolic Horn feed Multiple horn feeds

Lecture 1 18 Case Study: C/Ku Band Earthstation Antennas Incoming plane wave is focused by reflector at location of horn feed. Geometric Optics

Lecture 1 19 Case Study: C/Ku Band Earthstation Antennas Feed horn is designed so that it will illuminate the reflector in such a way as to maximize the aperture efficiency. Maxwell’s equations

Lecture 1 20 Case Study: C/Ku Band Earthstation Antennas Feed horn needs to be able to receive orthogonal linear polarizations (V-pol and H-pol) and maintain adequate isolation between the two channels. V-pol H-pol

Lecture 1 21 A planar orthomode transducer (OMT) is used to achieve good isolation between orthogonal linear polarizations. Case Study: C/Ku Band Earthstation Antennas Maxwell’s Equations (“Full-Wave Solution”)

Lecture 1 22 Case Study: C/Ku Band Earthstation Antennas Horn Feed waveguide (WR 229) To LNB Stripline circuit with OMT, ratrace and WR229 transitions Maxwell’s equations

Lecture 1 23 Case Study: C/Ku Band Earthstation Antennas Single-ended probe Differential-pair probes Ratrace hybrid WR229 Transitions 50 ohm transmission line Layout of the stripline trace layer Vias Circuit Theory

Lecture 1 24 Case Study: C/Ku Band Earthstation Antennas The two linear polarizations each are fed to a LNB (low noise block). LNB

Lecture 1 25 Case Study: C/Ku Band Earthstation Antennas LNB: LNA Mixer IF Output: MHz (To Receiver) Local Oscillator BPF Circuit Theory, Behavioral Models, Information Theory