Lec14Smith - 1 1 Swartz ECE 488 – RF Circuits and Systems – Spring 2009 Lecture 13 ECE 488 RF Circuits and Systems Transmission Lines Smith

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Unformatted text preview: 1 1 Swartz 06/2/15 ECE 488 – RF Circuits and Systems – Spring 2009 Lecture 13: ECE 488 RF Circuits and Systems Transmission Lines Smith Charts Impedance Matching Fall 2009 Lecture 14 2009/2/20 2 Swartz 06/2/15 ECE 488 – RF Circuits and Systems – Spring 2009 Lecture 13: Announcements • Hand out copies of Smith Charts • Pass around samples of transmission lines 4 Swartz 06/2/15 ECE 488 – RF Circuits and Systems – Spring 2009 Lecture 13: The tan-tan Formula – Stub Tuners • S tub tuners are short stubs of transmission lines used to cancel out unwanted reactances in RF circuits. o Z = z − = z o Z = z − = z An open- circuit stub A short- circuit stub ( ) ( ) k j Z X j z Z o tan = = − = ( ) ( ) k j Z X j z Z o cot − = = − = Short open lengths used to cancel unwanted inductive reactances Short shorted lengths used to cancel unwanted capacitive reactances k X 2 π π 2 3 π π 2 2 5 π inductive capacitive k X 2 π π 2 3 π π 2 2 5 π inductive capacitive k X 2 π π 2 3 π π 2 2 5 π inductive capacitive k X 2 π π 2 3 π π 2 2 5 π inductive capacitive 5 Swartz 06/2/15 ECE 488 – RF Circuits and Systems – Spring 2009 Lecture 13: • Being inductive or capacitive does not mean stubbed transmission lines are the same as lumped elements, since T-Line Capacitors and Inductors is not proportional to as in . The frequency dependence is very different. ω ) / tan( tan ' phase v jZ k jZ Z ω = = L j ω 6 Swartz 06/2/15 ECE 488 – RF Circuits and Systems – Spring 2009 Lecture 13: • Moving up the transmission line: Position Along the Transmission Line Changes the Reflection Coefficient...
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This note was uploaded on 07/09/2009 for the course ECE 4880 taught by Professor Swartz during the Spring '06 term at Cornell University (Engineering School).

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Lec14Smith - 1 1 Swartz ECE 488 – RF Circuits and Systems – Spring 2009 Lecture 13 ECE 488 RF Circuits and Systems Transmission Lines Smith

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