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Questions tagged [high-frequency]

This tag marks questions related high frequency (radio) circuits.

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2answers
40 views

Passive Elements At high Frequency [parasitic effects]

What would the magnitude Response curve for a Resistor, Inductor and Capacitor look like [with parasitic effects not ideal components] ? From what I have gathered they would look something along the ...
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0answers
43 views

Resistors at High Frequency

[external R at 100] []1 1)Why is it that at high frequency the magnitude of impedance of a resistor (100) decreases? 2) At High frequencies a resistor would have a parasitic component of inductance ...
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0answers
40 views

Can this transitter on 319.5 MHz signal this receiver on 315 MHz?

In my pile of electronics pieces I have a wireless transmitter with this fcc id that supposedly transmits on 319.5 MHz. In the same pile of stuff I have a receiver with this fcc id that supposedly ...
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2answers
78 views

What's the role of Ground Plane in high frequency boards?

Here is an image of an LNB circuit: As you can see there is some Vias that is pointless for me(blue circles). Why didn't the designer connect these components to the ground line around the circuit ...
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1answer
60 views

What's this length-tunned shape in this circuit?

Here is an image of an LNB circuit: Probably you heard something about length-tunned traces that they use in high-frequencies PCBs. There is something similar to the length-tunned traces in the PCB(...
7
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1answer
1k views

Does it matter what size of via you use in high frequency circuits?

Here is an image of an LNB and there is some different "Via"s in the PCB that I don't know Why do they use different size of Vias in such circuits. Why? Any reason? I showed two Vias using two arrows ...
6
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2answers
493 views

What do these parts of this PCB do?

Here is an image of an LNB circuit: There is some parts in this circuit that I cannot know what they are. Marked them using blue circles. What are these parts and what do they do? They looks like ...
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3answers
123 views

What's this component and how could these screws affect it?

Today, I was seeing the circuit of an LNB deeply and a part of it catched my attention. Here is an image of the circuit: And here is two images of the bottom and the two components that catched my ...
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2answers
82 views

How to determine the current rating of Litz wire winding at high frequency?

How can we determine the current rating of a litz wire winding at high frequency? This is my try: For example, if we use 660/38 litz at 85kHz, we can see the equivalent AWG is 10 (reference). Then, ...
1
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3answers
95 views

High voltage to low voltage in ps/nanosecond time (Zener/opamp?)

So I have a signal that goes from 0 to ~800volts in 30ns. I would like to use this signal to trigger a camera (input impedance of 50ohm) which takes a max of 10 volts and requires the rise time to be ...
4
votes
1answer
99 views

Maximum via frequency

I am designing a 18 layer, 2.5mm board using the material FR408HR and I am wondering about maximum via frequency, because I should use them for PCIe 2.0 (5 Gbps). I have not found a specific ...
2
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0answers
56 views

High frequency switching applications

I was reading that for high frequency switching applications with semiconductors, the ratio of the electron to hole mobility should be high. Why is it so? Is it a necessary condition always? Or ...
26
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8answers
6k views

Why is 50 Ω often chosen as the input impedance of antennas, whereas the free space impedance is 377 Ω?

In order to efficiently deliver power to a different part of a circuit without reflection, the impedances of all circuit elements need to be matched. Free space can be regarded as a further element, ...
45
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13answers
9k views

Why do fundamental circuit laws break down at high frequency AC?

We're just starting the whole RF scene having dealt with DC and low frequency AC for all our previous courses. I understand that at high frequency AC, fundamental circuit laws don't apply anymore ...
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2answers
151 views

Is there any way to convert 50 Hz directly to 1 MHz? [closed]

I want to know whether there are any ways to convert 50 Hz AC to 1 MHz without Voltage Controlled Oscillators? If I'm correct, all the normal circuits convert the AC to DC and then use it to ...
1
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3answers
349 views

Is it possible to measure frequency upto 500Mhz with 50Mhz oscilloscope?

Is there a way to measure higher frequency measurements with a 50 MHz oscilloscope (eg rigol ds1054z)? Perhaps some post processing of captured waveforms? Or with the help of some adapters? I have a ...
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2answers
96 views

Design a tank circuit for class C power amplifier using ADS

I am trying to figure out the best values for the tank circuit values (L and C) in order to compare the amplifier's efficiency with the output power I have chosen the tank value L1 and C7 to resonate ...
0
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1answer
52 views

Impedance Matching Network with tracks+connectors in between (practice)

I've been struggling on how to design (and develop in practice) an impedance matching network with some traces/tracks/paths (whatever you wanna call it) and some connectors in between. So here is the ...
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0answers
85 views

Resonant, autotuned nanopulser

My need is to build (or purchase, if existent) a nanopulser, but not an ordinary one: it has to have some specific characteristics. The premise is: I have a device which acts as a variable capacitor ...
0
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2answers
65 views

High current/high voltage/high frequency measurement

I have a circuit that I'm having trouble understanding. It measures the current flowing through a conductor. The measured load is 20-100 Amps, 9kHz-34kHz, and approx. 340 volts. The main conductor ...
3
votes
2answers
202 views

How to amplify a low Amplitude, High frequency signal from Ultrasonic Transducer?

I am working with some ultrasonic transducers, the receiver gets a signal of around 10 mVp-p at 125 kHz and for its purpose needs a gain of around 10. So far have a simple inverting OP-Amp setup, ...
0
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1answer
75 views

EHF RF Transmitter and Receiver

We are working on a blood glucose meter that will measure BG readings through radio waves with a frequency between 60-70 GHz. That range is necessary to allow penetration through the tissue and we ...
0
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1answer
66 views

Asynchronous SRAM routing crosstalk concerns

I'm routing a large BGA SRAM that is connected to a BGA FPGA, and there's about 40 signals altogether connecting the two. I'm using Henry Ott's recommended 8-layer stackup: 1 ________________Mounting ...
1
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1answer
73 views

High voltage high speed low current amplifier

I want to design an amplifier that can take an 8MHz signal (even square) with an amplitude of only a few volts (1-3V) and amplify it up to 160V but I only need it to deliver about 60mA. I also want to ...
5
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4answers
2k views

Is there a small (6-pin) DIP I can use to generate multi-MHz squarewave clocks with an external crystal?

I'm building a circuit that I'd like to run at 8 MHz to begin with, but I want to be able to try it out at 10, 12, 16, 20, and, maybe, 25 MHz. I know that many microcontrollers have the ability to ...
5
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1answer
392 views

Build a High-Voltage High-Frequency Power Supply

I need to build a HV HF power supply to ionize gas. The specifications are 12V input voltage and 10kV output voltage @ 13.56MHz. I know this is not an easy task at all, since in this frequency area, ...
22
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3answers
2k views

Why solder mask are not applied to RF PCBs

I've gone through some of the RF PCB designs. In which solder masking on the traces are not present. Like this one Is there a specific reason or performance issue to remove that?
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0answers
28 views

determine the cutoff frequency of a nMOS in common gate with gate resistance

I have to determine the upper cutoff frequency of this circuit. I absolutely mustn't use the laplace domain because it's too time consuming so not compatible with the time I have at the exam. A rapid ...
0
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2answers
76 views

Sram circuit design recommendations

I'm trying to design a simple SRAM board (using a cypress Cy7c1011cv33) to connect to my lattice machox3 starter kit's pin connectors. But I have some design questions, after reading their "SRAM Board ...
1
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2answers
109 views

High Speed Signal on Large Circular Ring

It's frequently communicated that when working with signals in the Ghz range, routing is extremely important to signal integrity. Pretty much any inclusion of unnecessary stubs is out of the question, ...
0
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2answers
81 views

High frequency AM demodulation

I'm building an light communication device(pretty much lifi) using AM and am mostly done with every part except for demodulating the signal. The signal looks like with a 1.8432MHz carrier wave(serial ...
2
votes
2answers
56 views

Radars and high frequency relation

Whenever I seach for radar implementations, independently of application (weather, military, autonomous vehicles, speed limiters, etc) it always comes in many flavours: huge antennas, small antennas, ...
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1answer
127 views

Common source amplifier, source degeneration and determining the cutoff frequency

I have a n-MOS transistor with the following biasing network: I have to determine the cutoff frequency due to GS and GD capacitances The method used by my book is to first redefine the ...
0
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1answer
64 views

Multi-fixed-station AM receiver

I'm in the pencil-and-paper stage of building a radio receiver that has the following characteristics: AM shortwave/HF three fixed frequencies - 3.33, 7.85 and 14.67 MHz single upper sideband with ...
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1answer
40 views

Problem with calculating high frequency response of a CE amp

I have this amp: The parameters of the transistor are hfe=120, Cje=40pF and Cjc=4pF. I am also told to assume Cpi = Cje = 40pF and Cmu = Cjc= 4 pF. From that I should calculate fh and compare it ...
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0answers
894 views

Smallest circuit for Ultrasonic Mist Maker or humidifier

I am working on Ultrasonic Mist Maker or humidifier circuit, but does not found any good circuit. As search on google that we have to make about frequency 1.6MHz to convert water into mist. using ...
4
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1answer
387 views

How come esp8266 is able to generate 2.4 GHz wifi signals

I am wondering how it is possible to generate 2.4 GHz, if its core clock frequency is much lower than GHz scale.
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0answers
26 views

NMOS varactor Simulation Help?

I am trying to simulate a pair of NMOS transistors as varactors (BSD connected). However, am not getting any resonance at the particular frequency of interest. When I am simulating it, it is giving a ...
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1answer
47 views

Are there any examples on the use of the frequency spectrum between 40 and 42 GHz? [closed]

Since everyone started talking about 5G, I got curious about some parts of the frequency spectrum. I found out that some operators in the U.S. asked FCC if they could free the range between 40 and 42 ...
2
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1answer
85 views

Addition of HF Capacitor to Constant Current Source

The part of a circuit shown below was used in one of commercially sold audio amplifiers (constant current source shown here was added to differential amplifier, whereas voltage amplification stage ...
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1answer
61 views

RF Antenna design guidelines, PCB design Antenna [closed]

What are the parameters to be taken care to RF Antenna designs and RF circuits designs? What are the design criteria for RF designs?
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1answer
173 views

What would be the maximum frequency that can be achieved with an LC Oscillator? [closed]

What would be the maximum frequency that can be achieved with an Oscillator that is based only on Capacitors and Inductors ? Could it even reach high frequencies like Gigahertz or even Teraherz or are ...
3
votes
1answer
341 views

High voltage (2-6 kV), high frequency (20-50 kHz) power supply how to achive

I need to make a high voltage (2-6 kV), high frequency (20-50 kHz) power supply in order to generate cold plasma (in Ar gas). I use a fly back circuit (found in web) could allow me to to that. The ...
0
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0answers
36 views

Are there UHF RFID antennas with entirely different azimuth and elevation?

To improve UHF RFID reader's accuracy, I want antenna that has long, narrow reading field. So it needs to be directional and have vastly different azimuth and elevation. I stumbled upon few articles, ...
1
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2answers
94 views

Availability of 0.01 pF and 1 pF chip capacitor with SRF more than 15 GHz

I am working on a parasitic steerable phased array antenna, designed at 15 GHz. I need to terminate one of the array elements with a 0.01 pF chip capacitor to achieve desired steering direction. I ...
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1answer
714 views

high frequency transformer basics [closed]

What is the working principle of high frequency transformer?? Does it steps voltage or frequency and how it is different from ordinary transformers found in market? P.S. I could not find proper ...
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3answers
208 views

Confusion regarding eddy current losses

I have been taught in my machine's class that eddy current losses are proportional to the square of frequency*flux density, this seemed so fair that I never questioned this. But my machine design book ...
2
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4answers
171 views

Fast (high) frequency hopping with off-the-shelf components

I am looking for the easiest solution to synthesize 1.6 - 2.4 GHz (qudrature) in steps of 4 MHz settle within 10-50ns precise timing control when to switch frequency (e.g., at rising edge of an ...
2
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1answer
160 views

Switching high voltage with consistent risetime

I'm trying to design an IEC61000-4-4 compliant EFT generator for in-house use, which is based on following schematic: I've been able to determine all values for all components, And I've been able to ...
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3answers
211 views

High Frequency Rectification

I am trying to monitor an incoming signal and get some properties from it. The signal is a sine wave +-5V at 900Mhz. I am trying to measure the amplitude and the frequency of the signal. I will ...