Transformer T1-1T Output Impedance [1 Attachment]
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Correction: The radius isn’t 1.92 it’s the distance between the normalized resistance point 1.0 and normalized resistance of 1.92.
From: PHSNA@... [mailto:PHSNA@...]
Sent: Sunday, December 27, 2015 10:11 PM
Subject: RE: [PHSNA] Transformer T1-1T Output Impedance [1 Attachment]
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Well I’ll take a shot at answering this and welcome any comments/corrections to my reply. The T1-1T is a transformer with a one-to-one turns ratio, so within limits its output impedance should be equal to that of the source its connected to. IF it were a perfect transformer which it isn’t. The Input Return Loss gives a measure of how imperfect it is. Let’s take the Return Loss figure for 80 Mhz. and call it 10 dB. So, if you connect the T1-1T to a device with a 50 ohm source impedance the output impedance of the T1-1T at 80 MHz. will be somewhere between purely resistive impedances of 96.2 and 26 ohms. To see all the possible impedances presented for the 10 dB return loss you can draw a circle on a Smith Chart centered on 50 ohms normalized to one with a radius of 1.92. See attached PDF.
Does the Transformer T1:1T has an output impedance of 50 ohm through all the transformer bandwidth?
Does the transformer output impedance change on high frequencies?
Bandwidth: 0.08 to 200 Mhz
Branch. Mini Circuits
Alfredo Mendiola Loyola