Questions tagged [high-frequency]
This tag marks questions related high frequency (radio) circuits.
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Why is the frequency response from my 1X and 10X probe seem to be converging with increasing frequency?
I'm a Mechanical Engineer trying to get into electronics so please excuse my lack of understanding.
I'm feeding a 5.0 Vpp sine wave into my SDS 1202X-E scope from my signal generator (see image below)....
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High frequency output between two phases [closed]
I have 3 phase ac generator , of late its frequency between two phases comes 100 hz although it is rated for 50 hz. Any idea whats wrong in this. AvR seems to be fine as changing AvR doesn't give ...
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What is the key circuitry in a form of high frequency signal generator that means power would be sent and reflected when there's an open load
Ive asked enough questions to explain why when there is an impedance mismatch there is power reflected which from my understanding is because there is a reflection of the waves, and also the cause of ...
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On-chip Co-planar Waveguide Design on Si – SiO2 Substrate
I want to design, simulate, and fabricate on-chip Coplanar waveguides (no bottom ground) on a Silicon Dioxide layer 5um thick on a Silicon 500um thick wafer. The metal electrodes will be 1um thick ...
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Debugging PLL STW81200TR not locking
I need a bit of debugging help with SWT81200 PLL that I am using on my custom designed PCB. I am able to configure registers through SPI communication, but the problem is that I am not able to achieve ...
2
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What is the purpose of this long capacitor/inductor chain on a DDS IC evaluation board?
Image of the B output stage of the EVAL-CN0304 AD9834 DDS Evaluation Board
IOUT_B is a current source, not potential source, so the initial say half of the circuit I get. The resistor gives us a ...
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36
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How to provide a low response time <1µs constant current source up to 1.5A
I need to provide a constant current source that can provide up to 1.5A current and a compliant voltage of 0-40V, with a low response time of <1µs. How should I approach this problem?
Common bench ...
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Measuring a 10-30 ns pulse width
For my school project over summer holidays I was tasked to measure a 10-30 ns impulse of a laser. So far I got the impulse on the oscilloscope, which I will run through a Schmitt-Trigger to get a ...
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2
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93
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Why can’t I find fast transistors and same fast diodes?
I am trying to make a 30 GHz 32 (or 64 bit) counter on flip flops.
Ready counters do not satisfy me due to max frequency and price, so I decided to make it on my own from flip-flops.
Ready flip-flops ...
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High swing (Low-voltage) cascode current mirror pole
I have been trying to figure out extracting the exact derivation for the poles, I am only struggling with figuring how the author got pole 8. I am using the small signal for the high swing cascode ...
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Part guidance: Switching 120 VAC @ 3 kHz in < 5 ms
I want to control electroluminescent wire, which runs at 100 Volts AC @ 1000 to 3000 Hz, with a desired switching delay of under 5 ms. I have used Sparkfuns products in the past, but they are no ...
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Which of the modern transistors could be a substitute for 2N709?
I need to replace the damaged Q1 transistor, but I don't have a 2N709. I was thinking about 2N2222 because of the similar case type. However, this transistor differs in frequency. In this follower ...
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How to simulate a Large Structure at low frequency in CST Microwave Studio?
In CST Microwave Studio, I attempted to simulate a large (215x30cm) loop structure at 1kHz. However, CST gives a warning of 'too large' mesh size. The mesh size increases up to 6 Billion, however, if ...
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High frequency voltage to current
I have a signal oscillating at tens or hundreds of MHz (up to 200 MHz expected), with 2.5 V mean and approx 200 mV peak to peak. I'd like to produce a current proportional to this signal at approx 40-...
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Trigger (Flip-flop) with under 3 ns delay?
I want to make nanosecond clock timer as a 64-bit counter.
There is a scheme (4-bit):
I am trying to find JK-trigger, or other, that can work with 300 Mhz clock speed, at least, i.e. 3.3 ns at most, ...
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Calibrating the R&S FPL 1003 Spectrum Analyzer
I am setting up an EMC test bench and I have a spectrum analyzer(SA): The Rohde and Schwarz FPL 1003 Spectrum Analyzer. I am trying to conduct some preliminary tests to ensure that the results seen on ...
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Shielded -vs- Non-Shielded, running CAN Data Cable w/ 115/200VAC 3-Phase @ 400Hz
*Edited, AGAIN, in an attempt to remove any confusion
Settle this debate!
I am designing a Harness for testing the functionality of a PDU (Power Drive Unit), operated using CAN (ARINC-825). Prior to ...
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Ways to get around amplification limited by op amp GBW?
I'm working on a project that requires me to amplify 70 pA to read out at 10 V (the digitizer I'm using to collect data has a range of 0 to 10 V readout). On top of this, I need to sample my voltage ...
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High speed (100 MHz) full wave rectifier
I would like to build a full wave rectifier of a RF signal (Vpp should be less than 1V) with a frequency of 10 MHz and carrier at 100 MHz. For example, this could be the signal:
If possible, the ...
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Could a DIY 1 kW portable version of the military non-lethal microwave beam active denial system (ADS) be made?
How would one create a portable 1 kW microwave emitter that projects out a 95 GHz beam to about 5 - 10 feet? What kind of components would be required?
I recently came across this fascinating video ...
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How can I find values for resistors and capacitors for an active bandpass filter with Rauch structure?
I have to find the values of the resistors and capacitors for this type of bandpass filter in order to obtain 105.5 MHz and 99,9MHz. I have found the transfer function, m, wc and the gain:
I am ...
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Problem about Instrument amplifier from LM358 at high frequency
I am researching about instrument amplifier circuit by use op-amp is LM358.
In this circuit gain is 1 by Rgain=R2=20k, R1=R3=10k.
Testing is define frequency range 1 Hz-10 kHz but when this circuit ...
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JFET Hartley Oscillator's Transformer [duplicate]
I have designed a JFET hartley oscillator but I couldnt order the transformer in our circuit. Can anyone help me on this subject. The transformer's operating frequency is 1Mhz to 3.5 MHz and I could ...
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Why is drain-source parasitic capacitance(Cds) omitted in JFET datasheets?
I've checked several datasheets on JFETs and I cannot find drain-source parasitic capacitance. They either include only Cgs and Cdg or they only include Ciss or Crss. Here are a few high frequency ...
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Multisim simulation of a current division
I'm currently trying to simulate a current division for three transmission lines that are in parallell (but all of different lengths). I want to study how the current divide itself as we progressively ...
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Why is the falling edge slower than the rising edge?
I have a radiation sensor connected to an amplifier and then to an oscilloscope. This is the circuit:
The radiation sensor (an LGAD) is connected straight into the "In" terminal, few ...
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112
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Fast unidirectional level switch from 5 V to 3.3 V
I came up with this circuit. Is it good or bad to use diodes? In my opinion, this is better than a divider or a FET, at least faster, as you can see from the waveforms. Will such a circuit create ...
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Can slower switching edges worsen the EMI behavior?
A common method (as stated in many electronic design articles/books) to reduce EMI (radiated emissions) of any fast switching circuit is to slow down it's switching edges (reduce tr/tf). This ...
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In what direction does skin effect take place?
I'm working with some problems with coaxial cylinders and the currents driven in those when considering high frequencies. In such cases, the skin depth has to be taken into consideration.
One thing I ...
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How to get freq stability with constant offset for PLL synthesizer?
I used ADF5356 PLL synthesizer. And i use reference oscillator freq is 10MHz with initially offset 0.1ppm and stability is 10 ppb. I need to output freq is 3750 MHz.
Expected output result:
10MHz × 0....
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Will this high-frequency PWM LED driver and MOSFET circuit work OK?
I am taking a PWM input (0-12 V) from a TLC59711 (driven by SPI from a Raspberry Pi) and I want to drive a P-channel MOSFET.
It is driving a 12 V, 40 W LED. I want to switch at high frequencies, as I ...
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High frequency sinks to MOSFET's drain?
I have the following setup on a custom PCB. The WT32-ETH01 module can be normally booted into download/flash mode by holding the IO0 to the GND during the start. The IO0 is also used as a clock ...
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Measure ≥ 200ns pulses (width and interval) as precisely as possible
I have a 0..5 V digital signal with a minimum pulse width of 200 ns.
I would like to measure the pulse width and the time between the rising edges of pulses.
In my case it would be enough to measure ...
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MOSFET is getting very hot at high frequency PWM
I want to drive a Litz wire coil at 250 kHz. I chose Arduino initially and then replaced it with NE555, but the Arduino or NE555 is generating 250 kHz, which is fed in a Litz coil to turn on some LED ...
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Matrix is singular
I have checked the other questions concerning this topic, but I can not seem to understand it. Here is my circuit. For some reason, it always says Matrix is singular. Does anyone know how to fix it?
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What happens to reflections when the distance between a capacitors plates is electrically long?
I understand what happens when a transmission line is terminated with a capacitor but what about when the distance between the plates becomes electrically long?
For PCB mounted capacitors I know this ...
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Creating a 10MHz clock grid
I have a round surface of 1.5 meters in diameter that contains many electronics. What I would like to do is distribute a 10MHz 3.3V clock signal from Teensy 4.0 across the table for 200 ADCs to access ...
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Op-amp compensation terminated to negative supply voltage instead of ground
I'm working on an amplifier for a SiPM and we are using the AD8099 amplifier in a transimpedance amplifier configuration.
I noticed that in the example circuits shown in the datasheet the compensation ...
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Air core inductor impedance vs frequency graphs
I wanted an inductor with at least 100 μH, so I used a PVC pipe and some enamelled wire (AWG 21 if I recall correctly) to create an inductor. The inductor does serve its purpose fine as a load ...
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Oscillator with low frequency drift
I need a ~70MHz oscillator with low frequency drift (less than 1%) over a wide temperature range (10°C to 50°C).
I dont have any experience with oscillators, so I have no idea which type of oscillator ...
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Considering USB 3.0 Cable and PCB Layout
I'm trying to connect usb Vision3.0 camera to Board.
There are cables and other boards between the camera and the board.
I am attaching the picture material.
I checked a few things.
USB 3.0 has 9 ...
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How ground plane acts as a low impedance path and shielding action of ground plane
I am new to high speed design .Please don't flame me if this question is very basic :)
Below statement is from AD application note. (AD Appnote)
"The ground plane not only acts as a low impedance ...
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Negative pulse at NPN collector when base switches off and reverse-active mode behaves better at HF
I have a system that detects pulses amplitudes with a peak detector, the signal from which is then digitized with an ADC. Pulses can sometimes overlap, so I've decided to "zero" the peak ...
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Placing of capacitor close to IC power pin - logic
I have 2 capacitors.
The first one is 100 nF and the other one is 1 μF.
When doing the layout, which capacitor should be placed close to the IC power pin and why?
I have seen in many places that the ...
user220456
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Do ADC do averaging of the voltage between 2 samples?
I'm using a 14bit ADC (on a Spectrum PCI acquisition card) at 500 Mhz, but this question is valid more generally.
Do ADC do some averaging of the voltage between 2 samples, or do they usually take the ...
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Very high ripple at the output of my converter
I need help on how to reduce this ripple at the output of my converter. I already have a 1uF x8 capacitor at the output, butI am still getting loads of noise.
Can you help with the best method to have ...
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How can I create a mist maker with a 9 V DC power supply?
Context
Note: I am a beginner with electronics so please provide detailed explanations and add descriptions that are more beginner friendly. I really do want to learn how this all works.
I am trying ...
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Why are analog signals preferred for high-frequency applications? [closed]
I really don't see what benefit analog signals would give over digital ones in this case.
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Why doesn't the whole signal get absorbed by the termination resistor in high-speed designs?
We normally parallelly terminate with a matching (50 Ω) resistor in high-speed designs. Normally, the load/receiver is high impedance, but if we terminate it with a 50 Ω resistor, wouldn't the whole ...
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Microstrip structures identification
I'm currently starting with learning how microstrip structures work.
Just for clarification: I'm talking about these here: Microstrips
In Power dividers and directional couplers, some basic structures ...
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