# Questions tagged [propagation]

The tag has no usage guidance.

125 questions
Filter by
Sorted by
Tagged with
117 views

### How to make minimum propagation delay pulse stretcher?

I want to stretch a pulse of 100mV and 1ns width to 3.3V and 10ns width with minimum propagation delay. I found a pulse stretcher in Linear's Application Note 87 document(https://www.analog.com/media/...
• 31
123 views

### How accurate is the antenna reciprocity principle in practice?

The Antenna Theory book by Balanis goes through a theoretical explanation. In my real antennas (I'm an Amateur Radio operator) there are other things like transmission lines and matching circuits. I'd ...
• 163
43 views

### Why do the short pulses in ultrawideband localization result in high accuracy?

I am currently reading about ultrawideband localization and came across the statement, that the short pulse duration that is used in UWB (for example ~2ns with 500MHz channel bandwidth) results in a ...
• 73
100 views

### Electrical wave propagation in wire vs space

Does it take the same amount of time for the lamps to turn on? Or does it take three times longer for the right lamp to turn on?
1 vote
244 views

### Timing parameters of sequential circuit - digital electronic

Problem Determine the timing parameters ($T_\text{cQ,bb}, T_\text{su,bb}, T_\text{h,bb}$) for the black box logic circuit seen below: - Attempt $T_\text{cQ,bb}$ is the time it takes for the ...
• 4,105
552 views

I'm a junior network admin at an ISP and need your help regarding point-to-point links with devices using the 60 GHz band. PROBLEM Most of them, except the ones that are at very close proximity (e.g., ...
157 views

### Propagation speed and capacitors charging speed of transmission line

I am a bit confused on the speed of voltage propagation in the transmission line and I hope someone can enlighten me. I understand the speed of step up voltage propagation is in the same order as the ...
123 views

### The effect of the wavelegth on the receiving power in Friis equation

In the Friis transmission equation, $$\frac{P_r}{P_t} = G_t G_r \left( \frac{\lambda}{4 \pi d} \right)^2,$$ it seems that if the frequency is halved while the other parameter values are fixed, the ...
• 311
466 views

### Visualizing the propagation of signals in digital electronic circuits [closed]

I am currently studying Computer Science, and in my Digital Electronics course, I was taught the basic stuff required for computer design. Also, I've recently started watching Ben Eater's videos on ...
767 views

### Why do buffers decrease delay?

Lots of people break up wires into stages to decrease RC delay. This makes sense to reduce the wire L and thus capacitance, but doesn’t the time for the signals to propagate through the buffers add ...
1 vote
28 views

### Phase velocity non-TEM transmission line

Assuming that a transmission line operates in a TEM or quasi-TEM mode, the phase velocity can be determined from the line parameters (R,L,C,G per meter assuming the RLCG model of a transmission line). ...
• 11
1 vote
94 views

### Propagation Delay of Sequential Logic Circuit

I'm trying to work through the above sequential logic problem from MIT OCW's Computation Structures course. However, I'm having trouble calculating tpd of the Zero output. I'm a complete novice at ...
63 views

### Phase Coefficient versus frequency plot

I have been asked to confirm that the propagation characteristics of a transmission line, with the given parameters R= 2.2 Ohm, L = 105nH, C = 69pF, G = 14 nS. Along with these two equations, I have ...
1 vote
83 views

### Speed of propagation of electric current and displacement travelled during a period

I read that "In general, the speed of propagation of electric current in a typical copper cable is about 70% to 90% of the speed of light, or about 210,000 km/s to 270,000 km/s" Let's say we ...
• 339
123 views

### Do electromagnetic fields undergo any variation between fields in time, or do such waves just expand in time and in their spherical plane?

In literature it is routinely said that an electric field generates a magnetic field, and thus one field creates the other "eternally", and that this explains their propagation. Am I wrong ...
56 views

### Amplitude Phase Shift Keying: Voltage Level Determination at Receiver

I am learning about communications via some of the coursework available here. In lecture 6 of the coursework, the author introduces the concept of Amplitude Shift Keying, and I have a question which ...
• 181
1 vote
250 views

### Logic buffers with discrete propagation delay

I want to have a circuit (for this matter a logic buffer) with a discrete propagation delay. It can be 5 ns, 10 ns or 15 ns, but I want deviations to be within 10-20% of these values. Where do I start ...
• 1,337
255 views

### Skew in half-bridge dead time generator in LMG5200EVM

The eval board for the GaN half bridge module LMG5200 (datasheet) contains the following circuit to generate dead time from a single PWM input. The half-bridge module itself has good propagation ...
• 22.4k
507 views

### Temperature dependency of charge carrier mobility and resistance in MOSFETs

I am a little bit confused about this. I used to think that in regular conductors the resistance increases with an increase in temperature because the charge carriers collide more frequently and thus ...
• 33
343 views

### Many (100) isolated slaves in SPI bus with 10 m cable

I am designing a device where 100 slaves are connected to a master with SPI bus and the bus must be isolated on each node. Speed requirement is 1 MHz and cables are fairly short (about 10 cm between ...
1 vote
363 views

### Propagation delay vs max flipping frequency of a comparator

Almost all datasheets of comparators will show their propagation delay, which means the time it takes for the input pin's change to be reflected by the output. However, if we have a high-frequency ...
• 185
1 vote
294 views

### LTspice, modeling line driver with propagation delay (LH0063)

Question I'm trying to make a component model for the LH0063 single ended line driver in LTspice... The propagation delay is the dominant parameter for the frequency response but I'm having a hard ...
• 683
1 vote
108 views

### How to measure radio wave penetration and reflection through different mediums

I would like to do a few experiments to test how different EM radiation frequencies (915 MHz to 5 GHz) interact with 3D print filament materials (like PLA, PolyCarbonate, TPU, etc...). Specifically I ...
1 vote
100 views

### What energy/fields if any is generated when radio frequency is passed through a coaxial cable?

I am new here. Just had a question wondering if someone could answer. Let's say I have a generator that can generate RF and send it through a cable (coaxial) if I attached the end of that wire to a ...
2k views

### What does a chip's propagation delay vary on?

When looking up datasheets on logic gates, propagation delay is usually shown as a range. Sometimes there's a "typical" value in the middle, but there's a min and max listed. On what does ...
• 109
304 views

### Why does short band (high frequency) radio travel longer than low frequency?

In physics, we are taught that longer wavelength (lower frequency) have a lower attenuation in air, and thus is able to travel longer distances. However, when talking about radio channels, short wave (...
906 views

### Driving GPIO outputs with FPGA: How to guarantee outputs of pins are set at same time

I was recently asked a question by an interview. We were discussing a hypothetical device that needed to drive 8 GPIO outputs of the FPGA. I was asked how to reduce the influence of propagation delay ...
1k views

### I am unable to figure out how the answer to following question is 70ns

Here's the question: Each full adder has 2 AND gates 2 XOR and 1 OR gate so carry propagation delay for each full adder should be 80 ns by the data provided and as there are 4 full adders, so shouldn'...
• 53
362 views

### How does propagation relate to switching time of a circuit?

I have this circuit: I know how to measure the propagation delay between a certain input and output. In my homework, I am required to optimize the area of each transistor. One point that occurs to ...
1k views

### How will supply voltage affect propagation delay?

Here is my circuit: I want to measure the propagation delay between the input D and output Y. As I understand it, the higher the supply voltage VDD is, the faster the propagation is. When I measure ...
908 views

### Hold time constraint equation

I am trying to understand the equation for hold time in the Digital Design and Computer Architecture book: https://www.sciencedirect.com/topics/computer-science/hold-time-constraint Hold time ...
62 views

### I need an explanation for the dereviation of a factor in the Two-Ray Model in Wikipedia

In the Two-Ray model, I wish to understand how the marked factor in the attached picture has been derived. source: https://en.wikipedia.org/wiki/Two-ray_ground-reflection_model Is this factor the E ...
1 vote
829 views

### Do more logic gates in series mean more slowing of the output result?

I heard that every logic gate has a propagation delay in nano scale. As the digital signal propagates through the logic gates, the signal output result will have a delay. Even though the delay is so ...
332 views

### Glass of microwave oven

From a user who "doesn't know" anything about Maxwell's equations. How to explain simply the behavior of a transparent glass of a microwave oven? Lets the light pass ... but blocks the "...
• 14.4k
151 views

### From delay to distance?

I need to estimate the distance of a link having only delay values. How can I do that? I need to estimate this distance for ethernet and optical fiber links. I thought of doing it using the ...
1 vote
83 views

### Mismatch of requirements from JEDEC with recommendations Intel(Altera)

I am studying the workings of DDR memory, in particular the recommendations for PCB layout. One of the intel documents (Table 1–24; Page 70) has the following wording: "Propagation delay of clock ...
• 23
137 views

### Counting no. of clock cycles

This question was asked in GATE 2021. Here I am finding it difficult to "manage" propagation delay of XOR gate. Solving it using timing diagram takes a lot of time and rough space. Is there ...
• 387
1k views

### Holes in RF shield, what frequencies can escape?

So this is part of a theoretical design problem that I've come across not too long ago, and still can't find a satisfactory answer for it. Assume a large (infinite) metal plane with a round hole in it ...
• 1,097
47 views

### How to imagine the mathematical expression in the waveguide?

Below we see an example expression for the E-field. It has three components: polarization of the field propagation direction standing wave pattern In the photo below of the field "L" has ...
• 157
600 views

### Daisy Chaining Shift Register Concerns and Fan-out Limits

I've been tasked with massivly expanding some GPIO of a microcontroller, and my inital thought was to chain a bunch of SN74HC595 and SN74HC597 shift registers, however to get the ammount that's ...
• 193
310 views

### Latching Priority Encoder, circuit works but I don't trust it

I added a schematic even though the question is actually too simple for it. The datasheets for the devices are likely to be more revealing. The circuit is super simple. I have a 74HC148 priority ...
• 203
1 vote
2k views

### How to calculate measurement error in a voltage divider?

I'm trying to calculate the measurement uncertainty of the voltage represented by the ADC in +/- V or % of a voltage measured across R2 of a voltage divider. What would be the general way to tackle ...
233 views

### Delaying clock pulses without adding (much) extra circuitry (CMOS)

I have a counter (74HC193) counting up with Qn outputs being decoded by a demultiplexer (74HC138). My clock pulses (CP) are no less than 100 microseconds long and the interval between them is always ...
• 203
42 views

### Is RF propagation path loss symmetrical and independent of clutter location?

Scenario: Consider two measurement points, point one is about 3m above ground level within a cluster of buildings (such as within an office park), and point two is about 1km away with an elevation ...
1 vote
109 views

### Is there a reason IC in the DIP package seem to have a very high propagation delay and so a very limited admitted frequency?

I scrolled through Mouser and I noticed that when you search for ICs with very low propagation delays there are only IC avaible in packages quite hard to use for an hobbyst/noob like me with very ...
1 vote
558 views

### Propagation delay in shift register - in the context of a serial adder

The first figure (from Fundamentals of Logic Design, Roth/Kinney, 6th Ed, p.404) shows a serial adder which feeds in operand bits and stores the sum, and uses a D flip-flop to store the carry-out from ...
• 77
140 views

### Fast decoder with low propagation delay

I need to use a fast decoder to communicate with a SRAM memory, CY7C1041GN. The circuit I need to implement is the circuit suggested in the Example #5 of the document AN2408 .The suggested decoder in ...
• 917
1 vote
11k views

### CAN transceiver interconnection to MCU (Tx, Rx and propagation delay)

I am working on a CAN transceiver and its connection to a microcontroller (hardware perspective only.) Referring this appnote - What is CAN? My questions: In the above image, I see the CAN ...
There is a long transmission line 1.Characteristic impedance $Z_C=\sqrt{\frac{z}{y}}=\sqrt{\frac{impedance}{admittance}}$,and in the lossless line,$Z_C=\sqrt{\frac{L}{C}}$ 2.propagation ...