NuHertz: Introduction to the Advanced Interface

Title: Video 2 - NuHertz: Introduction to the Advanced Interface Hi, another video from Ozen Engineering. My name is Hatem Akel. I'm going to talk about the advanced interface of Newhertz. Newhertz is another tool available on the electronic desktop from ANSYS. It's a powerful filter design tool.

The interface is simple and easy to learn, and you can choose from tens of designs. Here is the Newhertz tool's interface. That's the advanced one. In a previous video, we discussed the FilterQuick interface, the one you see here. Today we will discuss the advanced one.

You can see we have a lot of options. To use this tool, you need to have some background on filters. Newhertz won't tell you what to pick. We have different options for the different filters. We have more options than what we saw in the FilterQuick interface.

We will select the Chebyshev type, where we have ripples only in the pass path. Filter class. Now you have to select what you want, whether you want to have a low pass, band pass, high pass, or band stop. In our case, we select band pass. In the filter specifications, we have a filter class.

Filter attributes. We need to enter the requirements. I can specify the order, the center frequency, the pass band, and the ripple in the pass band. This is enough information for the software to make the design. I can select to specify the stop band attenuation and the stop band bandwidth.

If I do that, the software will decide the order. In these designs, the stop band definition is the standard, which is 3 dB. You can change that. Instead of using the center frequency, we can use the corner frequency definition. So we have many ways of defining your filter. We can add Tx zeros.

So Tx, which is transmission zeros, which is for S 21. And the purpose of adding zeros is to improve the group delay, to improve the phase. You can also request to have an arithmetic symmetry. It's another way to improve the group delay.

If you do not select this option, the amplitude response of the filter will be symmetric, but the group delay will be bad. If you choose to use arithmetic symmetric, the group delay will be flat or almost flat. But the amplitude response of the filter will not be symmetric.

In fact, it will degrade a lot on the high frequency side. We will show examples in a future video. Add asymmetry in the physical design to overcome this defect caused by the arithmetic symmetry. This will give the software the capability to maneuver and create a better filter.

If you deselect the asymmetry and the arithmetic symmetry, now you can control more the ripple. You can have a constrained ripple. What does that mean? Usually, Chebyshev and elliptical filters produce a flat equi-ripple response in the passband. This increases the order of the ripple.

There are applications that require equi-ripple at the edge of the band only. Restrict the equi-ripple condition to a section of the filter. For example, 50%, i.e. only the top 50% of a filter for low pass or 25% on each side of the passband.

Doing that will allow the system to reduce the order of the filter. Single point ripple is a filter that is not a filter. It is a filter that is not a filter. It is a filter that is not a filter.

Single point ripple is where we restrict the response to one point to reduce the load again on the filter design. This can be accomplished by adding zeros at zero or at infinity. This is for people who are really expert in filter design. In future videos, we will bring examples of that kind.

And the last thing is the half-band ripple. So the traditional filter spreads its zeros. And the half-band ripple spreads its zeros across the band. For some applications, it is better to spread half of the zeros and leave the other half at zero or infinity.

According to the manual, this eases the sharpness of the group delay and aids in group delay equalization, accommodates potential manufacturing restrictions, and accommodates some planar geometry requirements. Again, we will show more examples in future.

As you can see, this stuff requires really strong knowledge in filter design. Now we come to this side. So we have so many panels. We will start with the topology one. Because we selected the distributed option, we have now many topologies. And we can select the comp-line one.

Now, when you choose any one of them, you will see that the topology will be selected. And of course, that will change the entries here. Tapped has different meanings for different filters. For comp-line, it means you want the input to tab to the first resonator, like you see here.

It tabs to the first resonator. But if you uncheck this, you see, the input will be connected directly to the first resonator. It will be connected in this way. So these are two different ways of tapping to the filter.

Equal width approximation forces the use of the same width for all the resonators. Set center Z0 if you want the filter line to have an impedance different from the filter line. So we go to the substrate panel, is where we define our PCB.

Newhertz needs this information to do the right design calculations. Select your transmission line. In this case, we selected micro-SIB. Depending on what you select, the substrate parameters will change. With the micro-SIB, as you can see, you can add a cover.

We need to tell the software the conductor and dielectric thicknesses. We need to figure out what materials we are going to use. Choose one from the list. If you can't find material, choose something that's very close. We can change it later on. In HFSS.

And when we take our design to ANSYS electronic desktop, we can change it later on. In HFSS. And when we take our design to ANSYS electronic desktop, we can modify the materials there. We can modify the materials there. Choose also your conductor.

As you can see, the numbers here are conductivity ratio with respect to the copper. Copper is 1. Gold is 1.43 and more conductive than the copper. Each dielectric material comes with its own dielectric loss. You can modify that by unchecking this trying to change this.

and checking this section now you can enter any number you want. We go to the geometry panel. So this panel is only applicable if you select to use distributed filters. We use this section to add some constraints to the geometry.

For example, in section one, we specified the geometry of the section that will be used to represent the capacitor. We do that by specifying the line width used as a function of the dielectric height. Then the software calculates the necessary length to create any capacitance required.

The same applies to the inductor section. Next, choose to split the stops into two parallel stops for wide stops. Practically, one upper and one lower.

Usually, all the stops are on one side of the line width, and the other on the other side of the line width and the other side of the filter, upper or lower. If you choose this option, you need to enter the width to dielectric height ratio that will trigger the split.

If I select four for example here, then split will happen if the width is greater than four times the dielectric height.

Once this has happened, the system will create two stops, one on top, one on the bottom, and that will increase the dielectric height and the other one will increase the dielectric height and that will increase the size of your filter. Check the alternate sub orientation.

This will do as I said by default, all the stops are on one side.

But by selecting this option, the filter design will alternate the location of the stop, one on top, the next one at the bottom, the next one on top, and so on, in order to minimize the coupling between these stops in the geometry limitations.

We enter what we call the manufacturing design rules, the minimum width, minimum gap, maximum width, maximum gap. Try not to select the minimum given by the manufacturer because that will make your design very sensitive.

Selecting adjust length on limit means you are allowing the software to adjust the length of any structure to the desired length of the structure and also to the geometry limitations in the UHC module, which other modules have opposite length and maximum dimensional dimensions of the graph sub bumps are possible but 2003 shows that the averages can be applied in überhaupt.

So the 90-degree stop you see here, but you can ask for radial or Delta stops for the radial ones, specify again if the software can split any large stop into upper and lower stops. You can also ask the software to alternate the stops one on top, the next on the bottom, and so on.

You can also implement offset stops so it can be attached to the transmission line or you can shift the stop away from the RF line by an offset. Why? To make it easy to manufacture. Here we add limits to the minimum and maximum angles for radial. Keep it between 15 and 20 degrees.

And then we can change the offset to the maximum and maximum for the Delta ones, use between 15 to 120. That's what's recommended in the documents. Now we come to the graphs. So these graphs are generated by pressing any one of these buttons that you see here in the topology panel.

In all of them, you can print the graph to a PDF, OneNote, or Orchard file. You can also copy to clipboard then paste into another application like PowerPoint, paint, or word. You can specify the limits for the y-axis. You can specify the x-axis by the way, is here.

This is where we specify the x-axis limit, whether for the frequency or the time domain ones. This is where you control the x-axis. We can also see these curves in text format. So you can see the numbers. Freeze button simply creates a copy of this graph.

Now, when you change the design, this curve will change, but this one will not change. So you can keep track of all designs. We can zoom in. We can move the graph left and right. We can restore the original shape if you click the right button. You will get a marker.

If you double click on it, you can modify the location on the x-axis. Here you can see the step response, the pulse response, and the RAM response. This is important for low pass filters. We don't see any values for bandpass or high pass filters here at the bottom.

We have the poles and the zeros by default. We see the poles and zeros of the s21, the transmission response. You can also see the one of the reflection. You can also request that the x and y units to be the same. You can change the grid to polar. So there are many things you can do.

You can also change the location of the poles and the zeros, but before doing that, you need to activate these two options here. The prototype will bring the poles and zeros of the low pass. As you know, any filter is originally a low pass being translated into something else. So far, so good.

We will restore the will be the tragedies and we will rane. Now, by doing this and by clicking this option, and as you modify them, you will see a change in the shape of the filter, which shows the transfer function. You can display the function of the low pass filter.

We talked about it here, the prototype. You can also show the function itself of the pass band filter. You can show the standard shape of the function. You can show the cascade shape in this format. You can also show the parametric one. They are all different ways of representing the same formula.

You can also select the number of digits. So you can see here we have four digits in each number. You can select to fit. Sometimes the formula is so big, so you want to fit it in one screen. But sometimes when you do that, you won't be able to read. You can also select to fit the numbers.

So it's better not to select this option and just scroll back and forth. Now that we finished defining our filter, now we can ask to synthesize the filter. So if you click here, we get this window. Here we see the filter schematic. You can see it in layout format. You can see it in 3D.

You can print, copy, annotate. You can create a netlist. You can even edit the numbers. You can also do Monte Carlo, where you specify which dimensions you want to be processed. And what are the numbers? What are the tolerance? How many trials? Do you want it to be uniform or Gaussian?

Here you can keep a record of all the traces. Here you can keep track of all traces if you are doing Monte Carlo more than one time. And finally, the export. Now you can export the data in a format in touch some format S, Y, or Z. You can also export the design to DXF.

You can also export the design to a 3D data. So 3D data is a generic 3D file that can be used in lots of applications. It creates a text file. Users can read this file directly. Some applications can read this file directly.

But others, the user has to create some sort of a script to do the translation. And the last thing is the export to ANSYS electronic desktop. So before doing that, you need to do some setup. So before doing that, you need to do some setup. So before doing that, you need to do some setup.

So you have to tell the system where do you want to send the design to a circuit or to HFSS or to HFSS 3D layer. You can ask it to start the simulation immediately after exporting. And what are the parameters that you want it to calculate? The S parameters and the group delay.

And here you can be more specific about which parameter to solve. And which format you want it. Do you want them to be displayed in rectangles, mid-chart, polar plot, table data, and the unit. Do you want to do optimization?

If you want to do optimizations in ANSYS electronic desktop, then you need to do the setup. So you see, if you select setup optimizer, automatically New Hertz will set up the optimizer for you. You can ask it to start immediately the process of optimization after doing the export.

And if you do that, you need to tell the system your goals. So you have to enter your band and the goal in each band. You can ask for full parameterization to parameterize everything. Here is about the boundaries. You can ask for radiation boundary condition or you can have it metallic.

Metallic means you are enclosing your structure in a metallic enclosure. Substrate geometry, that's how much they extend beyond the dimensions of the filter. You can have a buffer. Here you select the filter. You can select to go directly to ANSYS electronic desktop.

Or you can ask the system to save the design in a Python script. This is highly recommended because it will teach you how to use Python scripts with ANSYS electronic desktop. Now if you do it with Python, then you need to go to electronic desktop and run the script to create the file.

You can save and close. You can go back to the default configuration if you change things. You can append to an existing ANSYS desktop. You can overwrite an existing ANSYS desktop. So there are many options. We're going to talk about them in future videos one by one. Now you can export.

If you export, you just save it to a Python file. So this video was an introduction to the advanced ANSYS software. Now you can go back to the interface of Newhertz. There are many things we talked about and there are other things we didn't talk about.

In future videos, we will talk about more options. Depends what kind of filter we are designing and what are the requirements. Thank you for listening.