This is a copy of N2PK's website. Paul has decided to delete his website (See N2PK-VNA on message #5, Jan 2020) from ~Feb 2020.

Paul has made availalable a ZIP file of his entire web site, which has been uploaded as is, no changes made except for this preface. <vk3pe>

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This is a Smith Chart of a 9 MHz quartz crystal, in 100 Hz steps over a +/- 3 kHz range, nearly centered on the crystal's series resonant frequency. This plot shows that the impedance of a crystal, near series resonance, can be essentially modelled as a series RLC circuit. This model loses accuracy as the parallel resonant frequency is approached, which is dominated by a capacitance that shunts the series RLC network.

Series resonance for this crystal is also seen to be approximately 320 Hz below 9 MHz and the series R is approximately 14 ohms. Additional analysis of this data and measurements can be used to fully characterize the equivalent circuit model for this crystal.

Quartz Crystal Smith Chart


Please feel free to contact me with any comments or questions at: see above

Paul Kiciak, N2PK

Last updated: 19 Oct. 2006
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