Questions tagged [bandwidth]

Related to signal processing (a measure of the width of a range of frequencies, measured in hertz) or the rate of data transfer(or throughput) measured in bits per second

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47
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2answers
13k views

Why are USB devices slower than 480 MBit/s

Motivation With a signaling rate of 480 MBit/s USB 2.0 devices should be able to transmit data with up to 60 MB/s. However today's devices seem to be limited to 30-42 MB/s while reading [Wiki:USB]. ...
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4answers
15k views

Oscilloscope Bandwidth, what's it all about?

This question popped up to me a few moments ago. I was measuring what is intended to be a 50Mhz square wave of level 0 to 2.5, however what I saw on the screen is a sine wave that was centered around ...
16
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4answers
14k views

Is this a good design & layout of an active differential 'scope probe?

This question is an extension of Homebrew differential 'scope probe. I thought I should make this a new question though. I need to measure a 100Mb/s LVDS signal to check its integrity. I will try to ...
9
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2answers
2k views

When would you need a low bandwidth opamp?

This opamp has a unity gain bandwidth of 27kHz, which is by far the lowest I've ever seen. (I first misread the 7.7V/ms slew rate as 7.7V/\$\mu\$s, because that's the units most often used.) 27kHz ...
9
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4answers
8k views

How is rise time related to bandwidth of the signal?

Say, I want to limit the rise time of my digital signal edges to avoid dealing with transmission line effects. How do I determine the maximum frequency of harmonics in my signal knowing that my rise ...
9
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1answer
1k views

Confused about frequency and bandwidth in BP filter?

I am trying to design a simple bandpass filter and I am confused what should be my central frequency and bandwidth should be. I have a 1MHz square wave with 20% duty cycle, so the signal is on for ...
8
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4answers
2k views

Why do OOK transmissions have bandwidth?

With on-off keying, you have a single carrier wave at a constant frequency transmitting its presence or absence. Now I understand that the crystal will not be perfect so you will have some minimal ...
7
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1answer
3k views

Why do FM radio signals occupy greater bandwidth than AM?

If a 5kHz baseband signal is modulating an AM carrier wave, the sidebands will be centered around the carrier wave and the the signal will occupy 10kHz bandwidth. AM radio limits the upper modulating ...
7
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1answer
1k views

Wideband matching network design

I have read about matching networks, authors usually will describe a target impedance to be presented, to say, the output of an amplifier, and then they design the matching network. To widen the ...
6
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2answers
835 views

How to estimate the analog bandwidth?

I have created the low cost oscilloscope and need to estimate the analog bandwidth. I do not have any specialized equipment and just trying to estimate it by watching the response to the square ...
6
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1answer
677 views

What limits the modulation of digital signals?

I am trying to understand why there are different speed on different frequency bands. I see that e.g. ZigBee can do 250kb/s for both 2.4GHz and 868/915MHz, but <...
6
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5answers
1k views

What decides the range of FM band?

I read that the frequencies over which FM signals can be transmitted is limited between 88 MHz and 108 MHz. Why is it confined to a particular range and why specifically to this (88 MHz to 108 MHz) ...
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2answers
1k views

Real rise time with oscilloscope and probe

I'm still a bit new to this domain, just wondering if the rise time of a probe and the oscilloscope itself have to be substracted to the measure in order to recover the real measured rise time? Let's ...
6
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1answer
2k views

What is bandwidth?

I'm having hard time understand what bandwidth really is? The book i'm using defines it as the width of a signal's spectrum (where spectrum is the range of frequencies in a signal). So, for example, ...
6
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1answer
3k views

How does a zero in transfer function affect the bandwidth of a system

Suppose we have a system with the closed-loop gain: \$\displaystyle G(s) = \frac{\omega_n^2}{s^2 + 2\zeta\omega_n+\omega_n^2}\$ Which is the default two-pole system closed-loop gain. Let's also ...
6
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1answer
3k views

Is this measured rise time inaccurate because of limited oscilloscope bandwidth?

I don't have an LCR meter and wanted to learn how to use a fast edge pulse generator and an oscilloscope to do capacitance measurements as an academic exercise. In W2AEW's videos, he builds a simple ...
6
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2answers
1k views

Observing effect of household appliances on powerline communication

I had been recently working on Powerline communication modems (PLC). I put two PLC modems at different parts of my home and observed the data transfer rate between them. However, I observed that when ...
6
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2answers
8k views

Bandwidth vs sample rate in SDR

In software defined radio (SDR) I often see sample rate and bandwidth interchanged or maybe I'm misunderstanding... If an sdr can sample a 2 MHz wide slice of rf spectrum does that imply it would be ...
6
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1answer
374 views

Long-tailed pair - gain and bandwidth

I'm trying to understand this schematic of this differential probe: I marked some blocks. I have some questions about the block I marked "Long-tailed pair" (LTP). I have no experience with LTPs so ...
5
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3answers
1k views

How do I find an ADC circuit's bandwidth experimentally?

I'm trying to measure the bandwidth of a circuit that I've built. It's an analogue-to-digital converter (ADC) with some input protection and biasing. The ADC samples at a constant/fixed 50 kSa/s. ...
5
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4answers
17k views

Bandwidth of inverting and non-inverting op-amps

If the same op-amp is used in both inverting and non-inverting modes (with same closed loop gain using appropriate resistors), will the closed loop bandwidth of the op-amp in both cases be the same? ...
5
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1answer
264 views

What ultimately determines the speed of electrical media

I have heard several myths about this. Some have said "thicker wires mean faster speed" which I don't believe. Others have said different voltages and others have said higher frequencies. Take Coax ...
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5answers
3k views

What is the analog bandwidth of general purpose ADCs?

I am making use of the dsPIC33FJ64GP802's ADC to do Undersampling and for that, I need to know the analog bandwidth of the ADC of this Microcontroller. My signal is around a few MHz. I have already ...
5
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1answer
139 views

What makes the band of an antenna broader than others?

Even though I'm studying waveguide slot antennas, so the examples that I'm going to give are related to this topic, my question covers a wider range of topics. I already know about a couple of things:...
5
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1answer
691 views

Why are there two sets of ENBW correction factors?

For calculating the equivalent noise bandwidth of a non-brickwall filter, I can find two different sets of numbers, both of which claim they are similar things: ...
5
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1answer
99 views

2.6 GHz microstrip patch antenna with 100 MHz bandwidth

I'm trying to design a microstrip patch antenna @ 2.6 GHz. The result I got is good but the antenna is very selective and I haven't been able to increase the BW. Currently, the BW is 40 MHz and I ...
4
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3answers
13k views

Why all digital signals have infinite bandwidth?

Why digital signals have "infinite bandwidth"? Frequency is the number of cycles per second. I have seen before the formula that bandwidth=Maximum Frequency - Minimum Frequency. I remember I was told ...
4
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6answers
2k views

Why does more bandwidth guarantee high bit rate?

The definition of bandwidth is frequency range and it seems to be correct to say that higher bandwidth guarantees higher data rate. However, i do not understand why it does. Data rate depends on ...
4
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2answers
1k views

Op-amp dominant pole bandwidth

I have been playing around with an op-amp design using TINA from Texas Instruments. I have selected the LM301A. TINA says that this op-amp has a dominant pole at 5 Hz. I have put the circuit ...
4
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3answers
3k views

Why is an op amp's bandwidth higher at lower gains?

If I build a resistor network where the op amp has a lower gain, it is able to maintain its gain for a larger bandwidth. Why?
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5answers
3k views

Does the fundamental frequency affect the bit rate on a wire?

This is from the book Computer Networks by Tennenbaum: The bandwidth is still the width of the band of frequencies that are passed, and the information that can be carried depends only on this ...
4
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2answers
1k views

Simulating and Building a Multiple Feedback Band-Pass Filter

I have a distorted signal, and only want to allow frequencies between 95kHz and 105kHz. The input voltage is at 300mV peak to peak. Thus, I need a Pass Band of 10kHz and a Central Frequency at 100kHz....
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1answer
1k views

Why does the 802.11b DSSS signal have 22 MHz of channel width? How does the information get spread over that width? [duplicate]

This topic has got me so much confused. In terms of Wi-Fi, when we say the 802.11b has 22 MHz of Channel Bandwidth, what does it mean? When we refer to a particular Channel No. say Channel 1, it has ...
4
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1answer
7k views

SPI communication - bits per second vs Hz

I have been reading more and more about bandwidths and frequencies to try to solve the following problem, but I am only ending up more confused. (I have limited electrical/signals background.) I ...
4
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1answer
2k views

Practical Limit of Feedback Control Systems WRT Bandwidth

In a digital feedback control system, I'm interested in the practical limit of what the correctable bandwidth is. For example, given a very simple system: A sensor can sample a simple X position ...
4
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4answers
2k views

Oscilloscope: How are Bandwidth specification and Sampling Rate related?

I had thought that a (digital) Oscilloscope with higher Sampling Rate, would automatically have higher Bandwidth. That seems intuitive because of Nyquist Sampling Theorem. But I've read in several ...
4
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1answer
16k views

Required Bandwidth for ASK

In Amplitude Shift Keying, the bandwidth required is given by \$B=(1+d)S\$ where B is bandwidth, S is the signal rate, and d is a value of either \$0\$ or \$1\$. But how could the required bandwidth ...
4
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3answers
1k views

gain, bandwidth and GBWP of current to voltage converter with op-amp

It might be a silly question since I am new to circuits and have little knowledge about it. I've learned that gain of a current to voltage convertor with op-amp is determined by feedback resistor <...
3
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3answers
4k views

Does an Oscilloscope's bandwidth need to match or exceed the microcontroller's/processor's clock speed?

Looking to buy an oscilloscope for home use, I've seen the questions on here in regards to bandwidth. I'm interested in prototyping microprocessors with clock speeds 800+ MHz, but I shouldn't need an ...
3
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5answers
3k views

Transmission of a digital signal over a medium

A digital signal is said to have a infinite bandwidth. If a transmission medium cannot have infinite bandwidth then how can a digital signal be transmitted over such mediums? Please correct me if I ...
3
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5answers
788 views

How can I know a signal's bandwidth before sampling?

Shannon's theorem tells us the minimum sampling frequency based on the bandwidth of the signal which has to be sampled. But I wonder, how can I know the signal's bandwidth before sampling it? It is ...
3
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3answers
12k views

Calculating maximum data rates

A channel has bandwidth 3 KHz, signal to noise ratio is 40 dB find maximum data rate for 16 level encoding schemes. There are two ways to find channel capacity. First one is with Nyquist theorem and ...
3
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5answers
6k views

Nyquist theorem, seems wrong to me

For Nyquist theorem, for channels without noise the bit rate is: \$N=2B\log_2(L)\$ N= bit rate, B= bandwidth, L= number of levels Intuitively I say that it should be: \$N=B\log_2(L)\$ Indeed if L=...
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2answers
2k views

RF Narrow bandpass filter (crystal ladder)

I am currently designing a narrow band pass filter at around 8Mhz, using the crystals having a resonance frequency of 8Mhz. Using the tutorial from :http://www.giangrandi.ch/electronics/...
3
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5answers
333 views

Please explain this formula for the relationship between bandwidth and the temporal response of a photodetector

I am reading "Optoelectronic Sensors" by Didier Decoster and Joseph Harari. At section 1.8.2 they start explaining the relationship between rise time and bandwidth, and they give a very weird formula ...
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2answers
31k views

Closed loop bandwidth vs open loop bandwidth

Is closed loop bandwidth always greater than open loop bandwidth ? If not on what factors does it depend ? When can it be greater?
3
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2answers
730 views

Select appropriate bandwidth for sensor (MEMS gyroscope)

Short question: how to select the correct bandwidth for a sensor? Some further details. I'm working with an ADIS16260 (rate gyro) placed upon an industrial vehicle. This sensor has both an analog ...
3
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1answer
3k views

USB 3.0 Bandwidth Per Individual Port

Folks, Let's say I have a USB 3.0 card with four USB 3.0 ports on it. I just connected the card to my mother board. When we say 640MB/s of bandwidth for USB 3.0, is that bandwidth per port (or 640*4 ...
3
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1answer
648 views

Operational Amplifier gain bandwidth product

If the gain bandwidth product of an operational amplifier is a constant and |Vout/Vin| is also a constant does that mean that the operational amplifier will not function for all but 1 frequency? ...
3
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1answer
355 views

Why is the bandwidth for a matched filter twice the normal nyquist theorem one?

Why is the needed channel bandwidth for a matched filter higher than the normal bandwidth derived by the nyquist theorem (2B=R, assuming L=2)? After some digging I found this source that states the ...

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