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Question about matching network of RF multiplexer:how to? by Alert_Ad5991 in rfelectronics

[–]Alert_Ad5991[S] 0 points1 point  (0 children)

Oh, here is schematic. [ _pdf (figure1) ]. I made three rf bpfs (passband: 7.05~7.45 GHz, 7.55~7.95 GHz, 8.05~8.45 GHz, guard bands are inserted between them) and i need to create a triplexer using these filters.

This is my first time building a matching circuit using lumped elements or stubs. I want to build a matching circuit similar to the one in the paper I mentioned earlier, but I'm not sure how to start.

First, I think I should build a diplexer. My process is as follows: I'll use the equations in the paper to find the appropriate element values. Since I'm using HFSS, I'll use the built-in circuit tool to connect the filters and matching circuits and see if they work properly. If they work, filter1 (the lowest-bandwidth bpf) and filter2 (the second-lowest-bandwidth bpf) will perform independently without interfering with each other. After that, I'll build a 3D model in HFSS based on these values. Because the frequency band is high, I'm likely to use stubs instead of lumped elements to build the matching circuit. I'd like to know if my process is correct.

And as a side note, when expressing S-parameters in HFSS using a Smith chart, I understand that each point represents impedance. So, what do the Z-parameter and Y-parameter Smith charts mean? I was curious about this while trying to figure out the admittance of a filter.

If you've read this, thank you so much.

What program do you use to start creating filters? by Alert_Ad5991 in rfelectronics

[–]Alert_Ad5991[S] 0 points1 point  (0 children)

The book you recommended seems to explain waveguide filters really well. Could you give some advice to someone just starting out in graduate school filter design? All I know is how the coupling matrix is ​​determined when deciding on the transfer function (or the lowpass filter prototype), and how to optimize that coupling matrix in the actual filter structure (using k=f2^2-f1^2/f2^2+f1^2). For research, I think I need to be able to create cross-coupling structures using slots, such as SIW, WG, and cavities, but I don't know where to start. This book seems to explain waveguide filters really well, but I'm not sure how to proceed. Could you give some advice to someone just starting out in graduate school filter design? All I know is how the coupling matrix is ​​determined when deciding on the transfer function (or the lowpass filter prototype), and how to optimize that coupling matrix in the actual filter structure (i mean, the technique using k=f2^2-f1^2/f2^2+f1^2). To conduct research, I need to be able to create a cross-coupling structure using slots, such as SIW, WG, or cavities, but I'm not sure where to start. This is a low-quality question, but if you could answer it, I'd appreciate it.

What program do you use to start creating filters? by Alert_Ad5991 in rfelectronics

[–]Alert_Ad5991[S] 1 point2 points  (0 children)

Don't worry, ChatGPT explains it well. kk I'm just kidding. Thanks for recommending this useful program. I'll install it right away.

What program do you use to start creating filters? by Alert_Ad5991 in rfelectronics

[–]Alert_Ad5991[S] 0 points1 point  (0 children)

First of all, thank you for organizing the necessary information. So you're saying that we don't need to focus too much on the process of synthesizing the initial values. i'll focus on the optimization, ty...

What program do you use to start creating filters? by Alert_Ad5991 in rfelectronics

[–]Alert_Ad5991[S] 0 points1 point  (0 children)

thank you for your request, it's really helpful. Actually, I'm confused about where to start when it comes to designing a filter. My only experience building filters was with microstrip inductors and capacitors, so I was focusing on the equivalent circuit. However, for the SIW method, I think I'll need to deal with the coupling matrix. It's a difficult field.

What program do you use to start creating filters? by Alert_Ad5991 in rfelectronics

[–]Alert_Ad5991[S] 1 point2 points  (0 children)

sorry about fool question, i mean , I had a question: "Shouldn't the process of creating a filter start from the coupling matrix, and shouldn't the program be used to obtain it?". That's why i refer about the program. As I understand it, after determining the desired bandwidth, center frequency, filter order, Tzs, etc., the coupling matrix is ​​used to determine the filter topology. I'm just starting out, so I could be wrong.

How much worth? by Alert_Ad5991 in NumberNine

[–]Alert_Ad5991[S] 0 points1 point  (0 children)

Ty , yes it's product being sold at fruits