Questions tagged [high-frequency]
This tag marks questions related high frequency (radio) circuits.
334
questions
1
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1answer
34 views
disagreement between theoretical calculation and measurement of upper cutoff frequency of a circuit based on RG58 coaxial cable
For a 100 meters RG58 coaxial cable, according to the datasheet, the capacitance of the cable is 10 nF and the inductance is of 25 µH approximately. A sinusoidal voltage is applied at the input of the ...
1
vote
0answers
27 views
lowering voltage of high frequency signal
One of the parts I have is RAM (1.5V logic level).
The hardware communicating with it, is at a 1.8V logic level. The RAM signals are sent quickly - around 350-450Mhz.
So I am pretty sure I can't ...
0
votes
3answers
78 views
How do I amplify a square wave pulse of 4 to 8 periods at 3.5 MHz from +-2V to +-60V or more?
I am working with ultrasound sensors optimized for 3.5 MHz signals, and I want to test these using my PicoScope 5000 with integrated signal generator. The PicoScope is able to generate arbitrary ...
0
votes
0answers
17 views
circuit design to output high voltage MHz high frequency [duplicate]
I'm trying to design a circuit that outputs 4.5 KV alternating between two nodes at about 4Mhz. What would be the most efficient way of doing this? I thought of using 4 4.5 KV rated transistors as in ...
2
votes
1answer
70 views
Low cost swarm positioning
I'm looking for a way to make a swarm of sensors know their position using low cost, low power system (ie ESP32.)
Requirement:
low cost per device
low power use on devices
1m accuracy is enough
2D ...
0
votes
2answers
59 views
Why are high frequency signals not disturbed by stray fields?
I am trying to design an inductive position sensor based on a high-frequency signal.
It is mentioned that using high-frequency signals gives immunity towards stray magnetic fields.
Could anyone ...
1
vote
2answers
123 views
RF 50 ohm dummy load PCB design
I am a rookie on both RF and PCB design and I am currently trying to do a 50 ohm 11 watt dummy load project for 100MHz-1GHz.
My calculations are done for the load but I have some questions about ...
2
votes
3answers
78 views
How do bypass capacitors recharge in high-frequency if the PCB can't deliver high-frequency currents?
I understand the whole theory behind bypass capacitors, how they are necessary to deliver high-frequency currents to the IC, as the PCB in general has high-inductance, thus high-impedance in high-...
0
votes
0answers
24 views
Reasons to use open circuit stub over a short circuit stub
I am having trouble with this question which states: suggest two reasons why the use of an open circuit stub might be preferable to a short circuit stub in microwave circuit design (microstrip)
Could ...
1
vote
1answer
47 views
High Voltage Input
I am trying to make an high voltage arc generator which is approximately 2 kV output. Here I can easily drive this circuit with 19 volts (laptop battery). Just like in the circuit bellow, I connected ...
1
vote
1answer
57 views
Are there any effects on capacitance and inductance when operating at audio-frequency (i.e. 1kHz - 20kHz)?
At the moment, I study something about audio-frequency track circuits for railway applications and to understand its operation, an accurate model of such a circuit is required.
The circuit of audio-...
2
votes
1answer
140 views
A few questions about High Current on PCB
Original schematic:
My attempt at drawing the PCB:
The routes are drawn on both layers and the thickness of the power route is 600 mil(300 on top and 300 on bottom). It is necessary to support ~15A. ...
2
votes
3answers
108 views
Why do current-feedback amplifiers have a higher bandwidth?
The advice when dealing with amplifying high-frequency signals always seems to be "use a current-feedback amplifier, not an op amp". (see 1, comments on 2, 3 and comments on its question) But why is ...
1
vote
1answer
71 views
Low Voltage, High Frequency, High Amperage Power Supply Design
For an ongoing project of studying magnetic properties of various metals we need to use a power supply which can generate 25 V peak to peak, frequency 50- 500 kHz, 5A (PP) current. Frequency would be ...
0
votes
1answer
45 views
High Voltage LC Oscillator Circuit
I am interested in creating an LC oscillator circuit that uses a high voltage DC source. The DC supply is variable from 5-35kv. I have seen numerous posts about creating these circuits at low voltages,...
1
vote
0answers
46 views
Oscilloscope Phase Shift
I have a university research that i am conducting right now. My objective, as a first step, would be to phase shift an NRZ signal at high frequencies >40GHz, assuming this signal is already locked ...
0
votes
0answers
66 views
Skin effect at high voltage
I recently made a slayer exciter circuit in order to determine the resonant frequency of my secondary coil of my yet to build SSTC.
When running the slayer exciter at 40V DC the circuit consumes ...
0
votes
1answer
51 views
Conductivity and high speed transmission using aluminium slip rings
So I came across a Persistence of Vision globe based video where a YouTuber he makes DIY slip rings to power and control some LEDs as seen in this picture:
My question is, given the high rate of ...
1
vote
1answer
35 views
Measurement of transformer with a vector network analyser (VNA)
I have a planar air core (no ferrite) transformer in a PCB. I need to characterize the transfer function of this transformer from DC to 500 MHz using a vector network analyser (VNA).
My first ...
0
votes
2answers
67 views
Capacitors choice for MHz resonance circuit
I am implementing a resonance circuit (for wireless charging) in MHz frequency (\$5-10~MHz\$) , and now, I am looking for suitable capacitors. The peak voltages and current through the capacitors are ...
0
votes
2answers
65 views
What is the maximum frequency to use diodes for distortion?
What is the maximum frequency to use rectifier, Schottky or Zener diodes for cut off sin wave to square wave?
0
votes
1answer
30 views
Stream Audio and WebCam Video through Radio Frequency [closed]
I and my friend would love to make a better communication system between us since his internet connection is not the best and neither is mine. We are 20 km away from each other.
Our project is to ...
1
vote
2answers
116 views
How to drive an AD9850 at 100 kHz/s sweep using arduino or rasberry pi?
The basic problem I am interested in doing is using an ADXXX chip to make a linear frequency sweep through the HF bands, from 1-20 MHz. The sweep rate I would like to achieve is 100 kHz/s, which ...
0
votes
2answers
165 views
Why not using high frequency AC at homes?
I am a student at school but I learn electronics in parallel as I love it, all my knowledge came from the internet, so if there is a problem in my question please fix it.I came across something called ...
0
votes
0answers
79 views
How does this electrical ballast need to be wired to the flyback transformer?
I just got myself a flyback transformer and an electrical ballast for fluorescent lamps as I heard those can be used together.
The electrical ballast is supposed to generate a high frequency which ...
0
votes
1answer
19 views
Matching S22 with a metal plate at the output
So assume we have a highfrequency device which has a missmatch at S22. Some of my colleagues solder a little round metal plate, placed on top of the signalpath it self (shortly before the SMA ...
1
vote
1answer
48 views
High frequency filter circuit design
I am a trying to design a design an Electrosurgical interference suppression (ESIS) protection layer to filter out high frequency noise caused by Electrosurgical equipment during surgery. I am using ...
1
vote
1answer
32 views
What is “tap line”?
I am reading this article (https://arxiv.org/ftp/arxiv/papers/1901/1901.02069.pdf) where I have come across this sentence: "we first designed a
parallel coupled Chebyshev bandpass filter as shown in ...
0
votes
2answers
92 views
Antenna Impedance Matching, 0 Ohm Response
I'm currently trying to match some SMD antenna breakout boards. These boards have one type of SMD antenna, footprints for an SMD pi network and a 50 Ohm cable as connection to my VNA.
Now the problem ...
4
votes
1answer
69 views
Conformal coating of UHF (radio frequency) circuitry 400 - 1000 MHz
Do you have experience applying conformal coating on UHF circuitry (ISM band)?
Are there known issues (e.g. degradation of UHF performance) which arise when coating UHF components like filters and ...
1
vote
1answer
66 views
Choose RF block inductor value
I have inductor to block RF.
My signal is between 1 and 2 GhZ.
How should I choose the value of this inductor ?
1µH is enough ??
What are the other parameters to take care about ?
0
votes
1answer
35 views
Pads reflecting in controlled impedance strip?
Background
I'm designing a controlled impedance line for a 1900MHz signal travelling between SIM7000A cellular chip and an antenna.
Question
Tuning circuits are recommended for antennas with series ...
0
votes
0answers
16 views
lightning current with isolated cable
I am trying to understand what happend when designing a lightning protection system using isolated cable (with specified separation distance, lets say in this case with 0.5m).
Following IEC 62305 I ...
0
votes
1answer
57 views
Help with analysis of a signal that generates high frequency
I am trying to understand this circuit:
In circle 1: I don't know why we make two capacitor in noise circuit, we can't do just one?
In circle 2: The tuned circuit consists of capacitor C1 and ...
1
vote
1answer
79 views
Ways to decrease TVS diode capacitance
I am currently working on high speed ethernet data line, and I wanted to know if there is a way to decrease TVS capacitance.
I thought of putting two TVS diodes in series to reduce capacitance.
...
2
votes
0answers
43 views
Improve the frequency of Current Source Howland effect Op-Amp
I need help on a Howland Effect circuit with a current source purpose with an output of 600mA and a constant gain throughout a range of frequencies starting in 0Hz to 1Mhz. I am currently using an ...
15
votes
3answers
4k views
Why do microwave ovens use magnetrons?
With a lot of advancement in solid state electronics and signal manipulation, isn't it easier to simply take high amplitude signals with frequencies near 1 MHz and multiply the signals using diodes ...
0
votes
0answers
32 views
Conclusions about PFD/Charge pump simulation
I have built a Sequential NAND based phase detector with a charge pump that includes a differential amplifier and I want your help make some conclusions about the results I got running all the ...
0
votes
0answers
31 views
comparing between different phase detectors
I implemented two architectures of phase-frequency detectors and I'm interested to compare between them.
(I'm open for extra architectures that might solve problems that I'm not discussing here)
I'...
1
vote
2answers
93 views
Phase detection with non-ideal PFD
I'm trying to simulate for Phase Frequency Detector with the following implementation:
and inside NAND_PFD:
NOTE: the triangles on the right are inverters and not amplifiers.
I'm currently ...
3
votes
3answers
128 views
PCB design for 50MHz
I'm designing a rather big PCB which will have 64 nokia 5110 LCDs arranged in an 8x8 matrix and will all be controlled by a single microcontroller.
Each screen will have an 8-bit shift register as a ...
0
votes
1answer
49 views
Power devices max voltage, current, power, speed, etc. .. ratings
I want to know how to get the real world or the most recent or the reliable information about power devices max ratings in volt, ampere, power, speed .. etc., parameters.
I found this picture that is ...
0
votes
0answers
28 views
What is an equation that will show RF wave characteristics?
I want to show a RF wave on a spherical grid coordinate system. How can I show the RF wave when t = time and y = magnitude?
I also want to show curvilinear coordinate transitions of the RF wave ...
0
votes
0answers
190 views
Modulate/demodulate 125khz signal to 433Mhz transmitter module (2.5Ghz carrier)
I am trying to implement a project which consists of two circuits. Circuit A receives a 125khz AM signal and modulates it to 433Mhz CC1101 which then uses 2.4Ghz carrier to send at longer distance. ...
0
votes
1answer
50 views
Reduce Power of High frequency output signal (40khz)
I want to try and make the output power of the following driver board adjustable. At full power it runs at 100watt I. The board itself does not have an option to reduce the power output. The output ...
0
votes
1answer
103 views
Is isolation required for MOSfet gate driver's and microprocessor's power supply?
I have designed a 62W , 24V-5V buck converter operating at 250KHz.
I am using TI's UCC27200A gate driver and Infineon's Optimos 4.
The problem is that the driver doesn't have any kind of isolation ...
1
vote
1answer
86 views
Measuring the quality factor RLC circuit
I am trying to get the Q factor for this circuit but I don't know how to simulate it properly.
I did a frequency sweep from 1 Hz - 30 MHz.
The oscillating frequency is 16 MHz.
I can't get the ...
4
votes
1answer
312 views
Inverter Circuit using IR2113, TLC555 and signal inverter IC
Input DC = 30V
operating frequency = 10kHz
problem =
When I am at the no-load condition at the output, only the oscilloscope is connected, I am receiving the proper output. But when I connect a load,...
9
votes
4answers
2k views
Why does the cable resistance jump from a low value to high value at a particular frequency?
I am not well versed with transmission line theory so if you can redirect me to relevant material I'd be grateful. So I used Agilent 4294A to find resistance of a 2 metre long shielded twisted pair ...
1
vote
0answers
31 views
Decreasing phase noise of natural oscillators by passive resonant filter on-chip in the MHz regime
I was doing a literature research on microwave filters and to me it looks like passive SAW filters/resonators have the highest quality factor below 1.5 GHz, but with a high power loss. Coupled planar ...
