#### fobos3

##### Newbie level 6

Hi,

I am trying to simulate a transmission line in NGspice but it doesn't seem to give me the expected results. I have a 2.3GHz ideal source with a 50 ohm internal resistance connected to one end of the transmission line. At the other end I terminate the transmission line at a 50 ohm load. The characteristic impedance is 50 ohm.

The simulation results give me a match at half wavelength, however, as I start decreasing the wavelength the voltage across the load starts decreasing and when I reach quarter wavelength it gives me Vout=0.

Any ideas? Here is my source code:

I am trying to simulate a transmission line in NGspice but it doesn't seem to give me the expected results. I have a 2.3GHz ideal source with a 50 ohm internal resistance connected to one end of the transmission line. At the other end I terminate the transmission line at a 50 ohm load. The characteristic impedance is 50 ohm.

The simulation results give me a match at half wavelength, however, as I start decreasing the wavelength the voltage across the load starts decreasing and when I reach quarter wavelength it gives me Vout=0.

Any ideas? Here is my source code:

Code:

```
*.MODEL ymod txl R=0 G=0 L=341.8n C=136.7p length=15.9m
*Y1 Vin 0 Vout 0 ymod
T1 Vin 0 Vout 0 Z0=50 F=2.3G NL=0.1
Rout Vout 0 50
Rsource Vout Vsource 50
V1 Vsource 0 AC 1 sin(0 1 2.3G)
.control
tran 1000f 10n
plot Vout
.endc
```

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