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Overview of Electrical Engineering Lecture 8A: Introduction to Engineering 1 Foundations of Electrical Engineering Electrophysics Information (Communications) Theory Digital Logic 2 Lecture 1 Foundations of Electrical Engineering Electrophysics: Fundamental theories of physics and important special cases. Phenomenological/behavioral models for situations where the rigorous physical theories are too difficult to apply. 3 Lecture 1 Hierarchy of Physics Theories Involved in the Study of Electrical Engineering Quantum electrodynamics Quantum mechanics Schrödinger Classical equation electromagnetics Electrostatics Electrodynamics Circuit theory Geometric optics 4 Lecture 1 Maxwell’s Equations 5 Lecture 1 Information Theory Originally developed by Claude Shannon of Bell Labs in the 1940s. 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 material in this slide and the next has been adapted from material from www.lucent.com/minds/infotheory. Lecture 1 6 Information Theory Defines relationships between elements of a communications system. For example, Power at the signal source Bandwidth of the system Noise Interference Mathematically describes the principals of data compression. 7 Lecture 1 Exercise: What is Information? Message with redundancy: “Many students are likely to fail that exam.” Message coded with less redundancy: “Mny stdnts are lkly to fail tht exm.” Claude Shannon, founder of Information Theory 8 Lecture 1 Digital Logic Based on logic gates, truth tables, and combinational and sequential logic circuit design Uses Boolean algebra and Karnaugh maps to develop minimized logic circuits. 9 Lecture 1 EE Subdisciplines Power Systems Electromagnetics Solid State Communication/Signal Processing Controls Analog/Digital Design 10 Lecture 1 Power Systems Generation of electrical energy Storage of electrical energy Distribution of electrical energy Rotating machinery-generators, motors 11 Lecture 1 Electromagnetics Propagation of electromagnetic energy Antennas Very high frequency signals Fiber optics 12 Lecture 1 Solid State Devices Transistors Diodes (LED’s, Laser diodes) Photodetectors Miniaturization of electrical devices Integration of many devices on a single chip 13 Lecture 1 Communications/Signal Proc. Transmission of information electrically and optically Modification of signals enhancement compression noise reduction filtering 14 Lecture 1 Controls Changing system inputs to obtain desired outputs Feedback Stability 15 Lecture 1 Digital Design Digital (ones and zeros) signals and hardware Computer architectures Embedded computer systems Microprocessors Microcontrollers DSP chips Programmable logic devices (PLDs) 16 Lecture 1 Case Study: C/Ku Band Earthstation Antennas Simulsat Parabolic Multiple horn feeds Horn feed ATCi Corporate Headquarters 450 North McKemy Chandler, AZ 85226 USA 17 Lecture 1 Case Study: C/Ku Band Earthstation Antennas Incoming plane wave is focused by reflector at location of horn feed. Geometric Optics 18 Lecture 1 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 19 Lecture 1 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 20 Lecture 1 Case Study: C/Ku Band Earthstation Antennas A planar orthomode transducer (OMT) is used to achieve good isolation between orthogonal linear polarizations. Maxwell’s Equations (“Full-Wave Solution”) 21 Lecture 1 Case Study: C/Ku Band Earthstation Antennas To LNB Feed waveguide (WR 229) Maxwell’s equations Horn Stripline circuit with OMT, ratrace and WR229 transitions 22 Lecture 1 Case Study: C/Ku Band Earthstation Antennas Layout of the stripline trace layer Single-ended probe WR229 Transitions Circuit Theory Differential-pair probes Ratrace hybrid 50 ohm transmission line Vias 23 Lecture 1 Case Study: C/Ku Band Earthstation Antennas The two linear polarizations each are fed to a LNB (low noise block). LNB LNB 24 Lecture 1 Case Study: C/Ku Band Earthstation Antennas LNB: LNA Mixer BPF IF Output: 950-1750 MHz (To Receiver) Circuit Theory, Behavioral Models, Information Theory Local Oscillator 25 Lecture 1