EEVblog Electronics Community Forum
Electronics => Beginners => Topic started by: 3roomlab on October 15, 2015, 09:33:43 am
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i need some help in understanding the terminology/unit here, while searching the web to learn new stuff about high frequency PCB traces, i ran into this web calculator.
http://www.emtalk.com/mscalc.php?er=4.2&h=1.6&h_units_list=hmm&f=20&Zo=50&EL=360&Operation=Synthesize&Wa=&W_units_list=Wmm&La=&L_units_list=Lmm (http://www.emtalk.com/mscalc.php?er=4.2&h=1.6&h_units_list=hmm&f=20&Zo=50&EL=360&Operation=Synthesize&Wa=&W_units_list=Wmm&La=&L_units_list=Lmm)
what does it mean when it says electrical length in "deg" ?
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The number of wavelengths the line is long at the operating frequency expressed as degrees of phase rotation.
Important because (for example) a 90 degree open circuit stub will appear as a short circuit at its driven end due to the reflection from the open end returning delayed by 180 degrees (90 out + 90 back).
Many microwave circuit elements are made as printed patterns of the PCB substrate, filters, matching (and phase shift) networks, all that stuff is just printed patterns, often of carefully calculated transmission lines or stubs.
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The number of wavelengths the line is long at the operating frequency expressed as degrees of phase rotation.
Important because (for example) a 90 degree open circuit stub will appear as a short circuit at its driven end due to the reflection from the open end returning delayed by 180 degrees (90 out + 90 back).
Many microwave circuit elements are made as printed patterns of the PCB substrate, filters, matching (and phase shift) networks, all that stuff is just printed patterns, often of carefully calculated transmission lines or stubs.
thanks