I felt like this was a good trade-off for the difference in price and the ease of construction. With each Qucs release the number of analysis functions, and other data processing fea-tures, included in the Qucs equation set continues to expand9. 0.47 dB, is slightly higher than the best amplifier available, 0.25 dB, the detected signal to noise ratio difference was 1.2 dB.
This gave me a preamp with just under 0.5 dB NF and 30+ dB gain which, at the time, required two $10 devices. Notice in this example the SPICE optimizer ASCO is used to nd the values of L, C and LL which mini- mize CF1 and CF2. Both the S parameter data and the impedance data are displayed as graphs in Figure8. With Qucsator youll be able to use a file as the data input to be used in the application or to obtain a file from a data pack that has been processed by the program. Qucs post-simulation processing is also used to extract values for the real and imaginary components of the RF resistor impedance. Create your own circuits with Quite Universal Circuit Simulator. dropping resistors be added along with input and output connectors i.e. qucs is a graphical electronic circuit simulator. As the amplifier was already matched for 50 ohms, building the amplifier required only that the d.c. With this data, I built my preamp for 23 cm. I was able to get Mini-Ckts to supply me the NF and gain data below the operating frequency of 1.7 GHz for this device as the NF was still decreasing and the gain increasing below 1.7 GHz. It uses two of the Mini-Circuits TAMP 242LN+Amplifier which I believe now cost $15. Now, if you want to play around with it, get the Qucs project files.Attached is a copy of my article which contains a preamp design that covers 23 and 13 cm. The article Obtain S-Parameter Data from Probe (April 1994 issue of The Design Center Source), described useful subcircuits which permit both the transmission (S21 and S12) and the reflection (S11 and S22) parameters of a given circuit to be calculated and displayed using Probe. frequency and phase response of the filter. Once you simulate your design you are presented with a Bode plot, i.e. This is necessary because otherwise the system of equations would not have a unique solution. The validity and usefulness of the new formula is demonstrated for three design examples span-ning a large variety of frequency ranges, substrates and ra-tios. Note, that the capacitor’s values are fixed to 100nF and 200nF respectively. It allows the design engineer to directly obtain the op-timum SIW width without solving more complicated formulas presented in the literature.
This paper presents the package software implementation details and a series of typical application studies. The component values are then calculated using the standard equations. Qucs-0.0.19S is targeted at academic and industrial applications. You choose the desired cutoff frequency of the filter and enter it as the variable cutoff in an equation. Let’s have a look at the lowpass version: It comes in three varieties: lowpass, highpass, and bandpass. In this post I present a simple Qucs schematic for designing Sallen-Key Butterworth filters. One of its many nice and useful features is the ability to write equations so you can calculate all kinds of stuff from simple linear equations up to Fourier transforms as part of the simulation.
It’s free and sports a nice graphical schematic capture interface.
could not even obtain the source code 13 not a circuit simulator like the others. There is no indication (on the website) that spiceOpus is free software.
11 Octave can control the Ngspice and Qucsator simulation, and obtain data from raw-SPICE3f5 files using the. Qucs, short for Quite Universal Circuit Simulator, is as the name suggests a simulation package for electronic circuits. QUCS 13 Qucs,Qucs-S variant of XML Qucs/SPICE3 5 batch mode.