Hello Dear All,

I am a undergrad student. I am learning ADS as part of my project. First of all, i am extremely new to ADS. I am designing BJT circuit for my project. I have a few questions in terms of simulations.

Q1. Before, I was simulating BJT circuits using AC simulation command. First of all, I was making the start frequency to be 1Hz and Stop frequency at 1MHz, so ofcourse there was a frequency sweep, so the simulation results were showing decaying sine wave or some thing strange. But then i put AC frequency start and stop values to be same, then the waves were pure sinewave.

So in terms of BJT transistors, What simulation commands should i use. Actually my input signal is Current with respect to time. And the output is a voltage signal with respect to time.

Q2. To measure currents within a circuit, some one told me to use a Current Probe. Does it actually measure currents and if i measure current at two points. Lets say, a current at point1, I call it i1 and current at point 2, call it i2. How can i get a graph after simulation which shows (ic1-ic2) with respect to time?

Thanks Alot. I really would appreciate help in this. I really need some ADS help

Yours

S A Waheed

London

I am a undergrad student. I am learning ADS as part of my project. First of all, i am extremely new to ADS. I am designing BJT circuit for my project. I have a few questions in terms of simulations.

Q1. Before, I was simulating BJT circuits using AC simulation command. First of all, I was making the start frequency to be 1Hz and Stop frequency at 1MHz, so ofcourse there was a frequency sweep, so the simulation results were showing decaying sine wave or some thing strange. But then i put AC frequency start and stop values to be same, then the waves were pure sinewave.

So in terms of BJT transistors, What simulation commands should i use. Actually my input signal is Current with respect to time. And the output is a voltage signal with respect to time.

Q2. To measure currents within a circuit, some one told me to use a Current Probe. Does it actually measure currents and if i measure current at two points. Lets say, a current at point1, I call it i1 and current at point 2, call it i2. How can i get a graph after simulation which shows (ic1-ic2) with respect to time?

Thanks Alot. I really would appreciate help in this. I really need some ADS help

Yours

S A Waheed

London

Don't know what you were seeing / how you plotted the results, but there is no way to get the waveform vs time using AC simulation.

Use the Transient simulation instead. Name the nodes in the schematic where you wish to measure the voltages. Insert one or more current probes to measure the current. The voltage nodes will be included in the simulation results as voltage vs time. The current probes will be saved as current vs time. In the data display, you can write a simple equation, like this:

DiffCurr = Probe1.i - Probe2.i

then just plot the equation, DiffCurr.