Electrons Dancing with Photons in the Ocean of DigitsPeek inside of a cell phone… ! Lot’s of “chips” (Integrated Circuits) ! What’s inside of these chips? Copyright © Prof. Ali M Niknejad http://www.wired.com/gadgetlab/2009/06/gallery-deep-inside-the-iphone-3g-s/!Cell Phone by EE Courses Copyright © Prof. Ali M NiknejadHybrid Technology (Prius) Copyright © Prof. Ali M NiknejadSolar Cells Copyright © Prof. Ali M NiknejadCourtesy of Kuka Robotics Corp."Cyber-Physical Systems (CPS): Orchestrating networked computational resources with physical systems Military systems: E-Corner, Siemens Transportation (Air traffic control at SFO) Avionics Telecommunications Factory automation Instrumentation (Soleil Synchrotron) Daimler-Chrysler Automotive Building Systems Power generation and distributionEE Trichotomy ! Devices ! You can “touch and feel” devices ! Semiconductors are materials of choice, properties can be engineered ! Information is ultimately represented by electrons (and ‘holes’) and/or photons ! Circuits ! Any interconnection of devices that performs a useful function ! Digital circuits, analog circuits, “RF” and microwave ! Systems ! The theory behind EE systems. A model for the system that includes noise, non-linearity, feedback, and dynamics. ! Most often digital signal processing algorithms used. Copyright © Prof. Ali M NiknejadSome EE History Copyright © Prof. Ali M NiknejadTelegraphy ! First there was telegraphy – use “Vail” (Morse) code to send messages over long distances. ! Patented in the US in 1837 by Morse and Vail. ! West coast connected by 1861 " end of Poly Express. ! Telegraph cables run along train tracks moving both information, people, and goods rapidly along the country Copyright © Prof. Ali M NiknejadTransatlantic Cable ! Transatlantic cable completed by 1866 (worked only a few days before it failed). " Led to the advancement in the theory of transmission lines. Copyright © Prof. Ali M NiknejadBell ! Alexander Graham Bell was the first to be awarded a patent for the electric telephone by the United States Patent and Trademark Office (USPTO) in March 1876. ! 10 March 1876 — The first successful telephone transmission of clear speech using a liquid transmitter when Bell spoke into his device, “Mr. Watson, come here, I want to see you.” and Watson heard each word distinctly. Copyright © Prof. Ali M NiknejadTesla ! In 1891 Nikola Tesla demonstrate wireless transmission of signals and he suggested wireless telegraphy as an application. Copyright © Prof. Ali M Niknejad The induction motor, another Tesla invention.Bose ! In November 1894, the Bengali Indian physicist, Jagadish Chandra Bose, demonstrated publicly the use of radio waves in Calcutta (did not file for a patent). Copyright © Prof. Ali M NiknejadWireless /Radio ! Started as wireless telegraphy. The history of the invention of the radio is very disputed. ! Marconi widely recognized as an early inventor although he played a more important role in commercializing the radio. In 1895 he sent signals 1.5 km. Transatlantic in 1902. Copyright © Prof. Ali M NiknejadTitanic Boost in Radio ! In 1912, the RMS Titanic sank in the northern Atlantic Ocean. ! Wireless radio transmissions (telegraph) were used to report the ship’s location. ! Britain's postmaster-general summed up, referring to the Titanic disaster, “Those who have been saved, have been saved through one man, Mr. Marconi...and his marvellous invention.” Copyright © Prof. Ali M NiknejadEarly “Ultra Wideband” Radio ! In the beginning these sparks generated “ultrawideband” interference which represented “Vail” code. ! The systems were essentially passive (vacuum tubes and transistors were not yet invented) and just realized with LC tanks and transformers. Copyright © Prof. Ali M NiknejadFirst Audio Transmissions ! Reginald Fessenden: Invented amplitude-modulated (AM) radio, so that more than one station can send signals (as opposed to spark-gap radio, where one transmitter covers the entire bandwidth of the spectrum). ! On Christmas Eve 1906, Reginald Fessenden made the first radio audio broadcast, from Brant Rock, MA. Ships at sea heard a broadcast that included Fessenden playing O Holy Night on the violin and reading a passage from the Bible. Copyright © Prof. Ali M NiknejadAM/FM Wireless Radio ! The dominant telegraph company of the time was Western Union. They had a monopoly on telegraphy and they dismissed telephony and radio. ! Telegraph gave way to audio transmission, mainly phone lines and broadcast radio. ! Frequency modulation (FM) was invented by Armstrong in 1935. FM has greater noise immunity than AM but requires more bandwidth. Copyright © Prof. Ali M NiknejadDigital Communications ! By sampling a signal and quantizing it (turning it into finite precision numbers), we can easily store it using digital technology and we can also transmit it digitally. ! Audio signals, for example, need to be sampled at about 20,000 times per second and with a resolution of around 18-bits to completely retain the fidelity of the signal (for the human ear) ! Today information is still transmitted with AM and FM, but the amplitude and phase of the signal are mapped into a finite alphabet. These digital signals are more noise immune and can be coded (guarded) to prevent, correct, and detect errors in transmission. Copyright © Prof. Ali M NiknejadDevices Copyright © Prof. Ali M NiknejadDevices ! Devices: Physical stuff you can “touch and feel” ! Manufacturing driven largely by integrated circuit (IC) fabrication ! The building block of ICs: Transistors ! Transistors used to make: ! Logic gates, memory, amplifiers ! Devices include electronic devices and optical devices ! Electron (and “hole”) transport through metals and semiconductors ! Semiconductors can be engineered to have specific properties (conductivity). The junction between two semiconducting materials is where the magic happens ! Photons (light) used to carry information through waveguides (fiber optics) or through electromagnetic radiation (radios, wireless). ! Semiconductor junctions can generate photos or detect photons (optical receivers, solar cells) Copyright © Prof. Ali M NiknejadThe Transistor ! Invented at Bell Laboratories on December 16, 1947 by
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