Band pass filter Puns

So I’m currently trying to build a bandpass filter for hydrogen line radio astronomy (1420 MHz) and I’ve settled on the hairpin filter design. The only problem is that after etching my first attempt I realized that it doesn’t pass the dc bias current which I need to power my LNA. Can I add a second filter in parallel that only passes the DC current (if so what does that look like? Most filters seems explicitly designed to do the oposite)? Do I need to abandon the hairpin filter completely? Something else?

Hi. For a school proyect im making two band pass filters in microstrip (using ADS and CST Studio)

My idea is to be able to combine them (with rf switches) to have a wider band pass filter or to combine one of the filters with a LPF/HPF for example (up to 4/5GHz).

I know that with the two BPF in cascade the stop band affects the other filter so i was thinking to use some kind of op amp or mixer but im not very familiar with RF components/techniques to know where to look (currently learning)

I was able to design the filters at 2.5GHz and 3GHz (BW=500MHz on both) but know i have to combine them (to have a wide 1GHz BPF). Ideas? Papers? Books?

Thanks!

I took a speech signal and then I applied a low pass filter , a high pass filter and a band pass filter on it separately but when I add all of them it should give me exactly the same but it shows small variation. Is this possible ? i also see the variation when i apply fft

Hey guys trying to implement a chip antenna(2.4 ghz) to a pcb design and some chip antenna documentation indicates for a matching network some doesnt.

my main question is can i use a band pass or low pass filter instead of matching network or they are 2 different things.

i got confused because if you look at the RFX2401C datasheet just before SMA connector there 6 components which are pi network or matching circuitry i guess. and if you install FL1 which is a low pass filter you can skip all that 6 components. so does it mean that low pass/band pass filter is a matching circuitry as well?

some of the notable features of rfx2401c regarding the matching:

-Single-ended 50 Ω input and output ports

- Full on-chip matching and decoupling circuitry

rfx2401c datasheet: https://www.mouser.bg/datasheet/2/472/RFX2401C_204359B-1524606.pdf

chip antenna datasheet: https://www.johansontechnology.com/datasheets/2450AT42B100/2450AT42B100.pdf

https://preview.redd.it/m17lr2brsw041.png?width=1066&format=png&auto=webp&s=36bfe4fdcd27572f18e8de11fb302286befe3f51

I am installing Orion CM65 mid range speakers in my car. The amp I will be running them off of will only be able to apply a high pass filter. I will have the tweeters on the same channel. so I will have the high pass filter at 100 Hz. The tweeters I bought have a crossover. But I don’t have a crossover for my midrange. But my question is for my mid range is do I need to build a passive bandpass filter or is it OK to send a signal that with only a 100hz high pass filter on it so basically it will be from 100Hz up to 20khz or so to my Orion speakers that only have a frequency response of 100 Hz to 10khz.

I found a bandpass calculator on line I have attached a photo. This will be all passive not active FYI

https://imgur.com/4cI9c2y

I have a problem where I need to design a simple band pass filter. It has a lower cut off frequency of 5kHz and an upper cut off frequency of 15kHz.

Could anyone give me some advice as to how to go about this? I assumed I would do it with an RC circuit but i need to know what order it is going to come out as.

Anything appreciated. Thanks

I’ve constructed an adjustable band-pass filter from 10KHz-100KHz. When I run my sinusoidal input through the filter, the values of the output are near perfect to the original wave (if the frequency is allowed). But when I run frequencies below 10k and above 100K they still pass through but at a significantly less amplitude. My question is, how do I completely drop this output amplitude of frequencies not in my band pass range?

This is a diagram for a second order band pass filter. I know it’s definitely a second order filter because there are two frequency dependent components, the inductor and the capacitor.

When I use voltage divider, I get the right transfer function. But when I use KVL as shown in the picture, the result I get is for a first order function and is incorrect. There’s no way KVL is wrong, how can I make it work?

Hi!

I need to know the equations for the inferior and superior cutoff frequencies of a Sallen-Key Band-Pass Filter, and I don't know neither where nor how to get them.

I've been reading many many places but all I find is the equation for the 'center frequency' f0. I need the frequency where the Pass-Band zone starts, and the frequency where it ends.

Here is the Wikipedia page where it shows both the circuit and the equations available (in every other place I've found the same equations). Diagram and equations

Band-Pass Sallen Key Filter

Thank you so much in advance

I was taught in a class that a Gaussian can be produced like this:

x = -20:19;

sig = 0.1; % our standard deviation

g = fspecial('gaussian',[1 length(x)],sig);

1. I'm a bit confused by the notion of a wave number or if there is a way to avoid having to deal with it altogether. https://en.wikipedia.org/wiki/Wavenumber I found this this quote from wikipedia below but it doesn't seem right for what we're trying to do:

"A wavenumber in inverse cm can be converted to a frequency in GHz by multiplying by 29.9792458 (the speed of light in centimeters per nanosecond)."

2. How do we get a Gaussian's horizontal axis units to be cycles/sample ?

3. I tried mixing the signal to shift it to a new center C on top of the old graph but am having issues because I only see one curve even though I changed the center of the second one

x = -20:19;

sig = 0.1; % our standard deviation

g = fspecial('gaussian',[1 length(x)],sig);

figure

plot(x,abs(fftshift(fft(g'))))

xlabel('Wave Number');

ylabel('Mag');

title('Gaussian');

C=0.2

BPF_center = 2*pi*C/Fs;

shifted_gaussian= g.*exp(-1j*BPF_center.*n.');

hold on

plot(x,abs(fftshift(fft(shifted_gaussian'))))

4. Alternatively, if you did not want to mess with wave numbers at all, how might you go about this to get your Gaussian bandpass filter to have its horizontal axis be in cycles/sample?

Hi everyone! I wanted to know if it were possible to have a pot that act as a passive variable band-pass filter with push/pull bypass for each pickup?

I want to have wiring with 1 3-way toggle switch, 2 volumes, 1 master coil split switch and 2 of the above with humbuckers on a guitar with mono and stereo outputs.

If someone helped me with the diagram it would be nice!

I've been thinking of playing with a 7w transmitter (the transmitter is the czw-7c), but, i've heard that they are too dirty and can destroy signals from other radios, or even interfere with airband, so i decided to use a filter. There is one being sold from china as well, but it says it is adequate for a receiver (and not a transmitter), and also its maximum power is 30w (if i'm not wrong).

Am i right to suppose a low pass filter for a transmitter is not distinct from a low pass filter for a receiver? that they can be used in both? Or would i not be able to use this "receiver band pass filter" in my transmitter?

Thanks.

I want to build an active bandpass filter into a pedal and I was wondering if it was possible to make this bandpass sweepable with a pot?

Hey there everyone,

I just wanted to get everyones opinion on crossover design and the specific filter elements and the effect of time/phase issues.

Obviously, a band pass filter provides more specific electronic filtering on paper, but can be more of an issue from a phasing perspective, and the extra elements required to build the network are going to take up valuable space.

With most BA's having quite a wide bandwidth, and wanting to avoid as many phase issues as possible, and assuming we're designing a 3 way system, I was wondering what everyones thoughts are on just using a low pass filter with acoustic dampener for lows, just a high pass with a dampener on the mids, and a high pass with a higher set point for the highs.

With any cross over there's going to be phase/time issues, but with limited space and the bandwidth's of BA's being so wide, I think this is an interesting topic, and I would enjoy discussing this topic in a little more detail.

I'm a mechanical engineering student. I'm currently in circuits and have no idea what's going on.

We've been tasked with making a circuit that filters audio between two speakers. We only have resistors, capacitors, and inductors at our disposal. One speaker is supposed to play sound below 880Hz and the other plays sound above 880Hz. The low-frequency speaker must be able to play audio lower than 440Hz and the high-frequency speaker must be able to play audio above 1760Hz. I have Multisim at my disposal and made a circuit that produces sound depending on what I make the voltage source frequency, so I know it at least reads in the frequency and plays it. I don't know where to put the second speaker, I don't know how to make it split the signal between the two. The circuit I'm using was given to me, so I don't even know how THIS circuit works. I watched videos on YouTube explaining how they work but I still don't understand. Electrical is not my thing, I guess lol

Here's the circuit I'm using.

Any advice or information would be greatly appreciated.

Hi everyone! I wanted to know if it were possible to have a pot that act as a passive variable band-pass filter with push/pull bypass?

I want to wire a guitar with 1 3-way toggle switch, 2 volumes, 1 master coil split switch and 2 of the above. It has humbuckers, mono and stereo outputs.

If someone helped me with the diagram it would be nice!