Questions tagged [waveguide]
A waveguide is a physical structure that guides electromagnetic or sound waves. They are most commonly employed at high frequencies such as microwave.
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From the perspective of a progressive wave, what is lumped impedance? [closed]
This question asks about the meaning of lumped impedance in traveling wave theory.
Should lumped impedance be viewed as something like a point charge, a point mass, or a direct delta function?
When a ...
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Conformal Mapping in Electrostatics: t-plane
In the paper 'Extension of the application of conformal mapping techniques to coplanar lines with finite dimensions' the author uses the t-plane as a intermediate step for calculating the capacitance ...
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Interruption in waveguides
I want to fabricate a PE waveguide.I deposited a layer of aluminum with a thickness of 180 nm on Lithium niobate.I lithographed the design of the waveguide,After developing photoresist and etching the ...
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Which stackup to choose for JLPCB FR4 up to ~10GHz
I am aware that 10GHz on FR4 is not ideal, but this is an hobby project and I can tolerate some losses. The 10GHz on the PCB is minimal (probably only a short coplanar waveguide or microstrip with 2 ...
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Ansys AEDT and Icepak Simulation
I have designed slotted coax cable based waveguide and FR4 is not getting any heat and even the coaxial cable does not get any heat which I do not understand why. E field as follows, ports include 2kW ...
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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). ...
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Unexpected low characteristic impedance using the JLCPCB impedance calculator
I'm currently designing a PCB that is intended to fan out the 38 pins of a MICTOR connector to every other conductor of an 80-conductor ribbon cable (The PATA type one, that is AWG30 wires with a 0....
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Circular waveguide excitation for TE11 coefficients
As we can see below, the theory says that A,B coefficients depend on the excitation.
I have simulated a circular waveguide.
How do I need to excite my waveguide so I will see the A and B coefficients ...
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Interference of RF currents with a combiner
I am trying to understand what happens to 2 RF currents flowing in separate planar waveguides (such as microstrip lines), when combined with a power combiner.
More specifically, will they interfere, ...
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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 to generate microwave band frequencies like 85GHz? Is there a DIY device or parts kit to do this? [closed]
Let's say I want to build a device that generates and sends out a microwave of some arbitrary specific frequency to a short distance, say 1 - 2 feet.
For example, 95 GHz.
Is there a straightforward ...
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Need help using RF transceiver with RF amplifiers
I'm trying to use the STM32WLE5C8 SoC that is both a microcontroller and an RF radio.
For my project I will be using the radio in the 800 - 900 MHz band (high-band configuration for this radio).
I ...
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Help with understanding waveguide dimensions for a pyramidal horn antenna
I want to build a pyramidal horn telescope as a science project but I’m having some trouble understanding the waveguide dimensions.
This documentation lists the dimensions of a paint thinner can be ...
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Minimum trace distance when using a via fence in a waveguide
I am trying to route several high speed JESD204B signals (up to 12GHz) to a connector and there is very small area for them. The manufacturer design note (p.113) recommends to route those signals on ...
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Effect of surrounding material on microstrip impedance?
If you were to have a microstrip transmission line PCB trace, which then had a dielectric material run completely on top of the PCB track coverlayer. Would this surrounding material affect the ...
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How do I find out the dimensions of a rectangular waveguide given the frequency I want to operate it at?
I want to design a horn antenna to detect the 21 cm hydrogen line. I know how to optimize the antenna dimensions by taking into account some functions that approximate the phase errors and ...
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Is there a standard that describes the term "coplanar waveguide"?
I look at IEC60050 "International Electrotechnical Vocabulary" standard at section 726 "Transmission lines and waveguides" and searching on the word "coplanar" gives me ...
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Why do dielectric waveguides support hybrid modes and metallic waveguides do not?
Can anyone explain to me qualitatively why dielectric waveguides (core and infinite cladding) support hybrid modes (E_z and H_z components in the guided wave), while metallic waveguides cannot?
I am ...
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The field in a waveguide at exactly the cut-off frequency
Can anyone explain to me qualitatively, what kind of field exists inside a waveguide at EXACTLY the cut-off frequency?
I would be grateful if an explanation was given about waveguides with metalic ...
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How can I tell whether a waveguide supports hybrid modes or not?
When studying metallic waveguides, it was taken for granted that the TE and TM (and potentially TEM) formed a complete set, that is, any electromagnetic field in the waveguide could be written as a ...
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I need help trying to set up a rectangular waveguide in HFSS,
Task:
Setup a rectangular waveguide in HFSS using four perfect E boundaries on the side
faces of a box and waveports on the end faces of the box. Set up your dimensions so
that at the lowest frequency ...
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Where is the azimuth and radial direction on the mode plot
Hello the photo bellow presents TE01 mode.
Where on the plot can i see the azimuth and the radial directions?
Thanks.
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How to interpret waveguide multi-mode S-parameters in CST
I have a cylindrical waveguide which is excited with two modes in each ports
as shown bellow.
However I cant see the meaning of S-params shown bellow.
photo one shows total isolation(-100dB)
While ...
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Why is a microwave oven equipped with a waveguide? [duplicate]
In a microwave oven, the magnetron connects to the waveguide. Magnetrons produce microwaves, which are guided into the cooking chamber by waveguides.
Why don't we directly connect the magnetron to ...
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Waveguides and optical fibres
Why at microwave frequency we prefer rectangular waveguides while at optical frequency circular waveguides (i.e. optical fibres). Can we have rectangular optical fibres.
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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 ...
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What is a guided mode?
I am currently reading my text, for my electromagnetics course, and we are discussing guided waves. The text casually mentions the term "guided modes", and never really defines what that ...
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Different 50Ohm-matched condition for different length of metamaterial waveguide
Based on coplanar waveguide, I am designing a meta-material waveguide by inserting lumped-element inductors along the center line.
Here are some parameters:
Target frequency: 10-20 GHz
Size of lump ...
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What is the impedance looking into a length of coaxial cable that is short-circuited at the far end and a half wave-length long?
What is the impedance looking into a length of coaxial cable that is short-circuited at the far end and a half wave long? I have been told that this the the basis of what is known as a wave guide &...
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Dielectric slab waveguide
let's consider the so called dielectric slab waveguide (references for image and equations: here, page 53):
I do not know much about it, I know only that it is a planar guiding structure which is ...
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Elliptical polarization and waveguides
It is known that a generic harmonic electric field which propagages in free space has an elliptical polarization (if you want to read the proof, look at this, slides 72 - 99).
My question is: what ...
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Engineering very high impedance resonator with coplanar waveguides
I have very little knowledge of electrical engineering, so please understand if my questions are somewhat trivial.
I have read that a coplanar waveguide (CPWG) acts as a lumped LC oscillator circuit, ...
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Can I get the S21 parameter from a one-port open, short and load reading?
I am currently working with a custom rectangular waveguide, which has one port abled to connect to a VNA,(call it port a) but the other side cannot, (its part of a bigger system but for now its only ...
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Designing waveguide based structure using cst
I am going to start designing waveguide based circulator , hybrid and loads using cst or ansys workbench.
I am quite familiar with the design of microstripline and stripline based systems using ADS.
...
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Shape of waves in waveguide
What is actually going on in waveguide when the wave is passing through it ?
If I am not mistaking , the plane waves are "fed" to the waveguide and there is a cutoff freq above which the waves can ...
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Evaluation of the dominant mode in a waveguide
In a waveguide, the dominant mode is defined as the propagation mode with the lowest cutoff frequency.
Now let's consider a structure in which the lowest cutoff frequency occurs for two different ...
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Geometric spreading of an impulse antenna
I am new to radar and curious about the geometric spreading in free space. I set up an air-coupled antenna about a half meter above the ground, with a large PEC on the ground. Then I adjusted the ...
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Waveguides Equivalent Circuits
I was reading in a book how to derive the equivalent circuits for TE, TM, TEM modes of a generic ideal (without losses) waveguide. After some computations, it found this equivalent circuit for TE ...
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Cut-off frequency in ideal waveguides
it is known that in an ideal waveguide (with a perfect electric conductor and with non-dispersive and non-conductive dielectric) there is a cut-off frequency, for each mode, such that for higher ...
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Excitation of a resonant cavity
let's consider this picture in which a cylindrical resonant cavity is excited through a waveguide.
I have some questions:
1) Why is it called "Magnetic Coupling"? I thought this excitation simply ...
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How to construct an SMA feedline for a horn antenna
I'm constructing an sma coax to waveguide transition for a horn antenna. Here's a cross-sectional view of what the device will look like
I can 3d print the waveguide portion (I use a conductive paint ...
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Impedance mismatch vs Signal attenuation
I'm currently designing a 50Ω grounded coplanar waveguide (GCPW) which connects an antenna to an LTE modem. My question is: does there exist a standard graph/chart that attempts to generalise ...
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Calculating dielectric constant of a dielectric sample placed inside a rectangular waveguide [duplicate]
Im trying to calculate the dielectric constant of a dielectric sample placed inside a rectangular waveguide over a range of frequenices. I used WR90 ( X band ).Using the s parameter data (S11 and S21),...
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Can anyone tell me how to find permittivity of a dielectric sample using a rectangular waveguide
Im trying to find the material paramters of a dielectric sample using a waveguide(X band) employing the Transmission/Reflection technique. While performing simulation in CST, how to properly orient ...
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Guided propagation in transmission lines
Can you help me on understanding why we may say this transmission line the propagation is guided and there is not any radiation?
It is a 2-conductors transmission line, in which the conductors are ...
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Considering Moding Issues in High Speed PCB Design
My question is a more generic one. I recently learnt about TE and TM propagation modes in waveguides. This made me think that when designing high-speed PCBs people always talk about matching the ...
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Radiation Source placement and waveguide parameters for Horn Antenna
I am designing ("arranging", actually) a horn antenna for a 77-81 GHz Radar. My module has a patch antenna which can't be placed inside the waveguide for some reasons. After the patch antenna, we have ...
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RF Design - Antenna Feed-line Parameters
I am implementing a BLE device with a chip antenna. The device has already been impedance matched to 50Ω and is ready to be connected to the feedline and antenna. The antenna datasheet has a ...
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What is the mode of a square waveguide \$TE_{11}\$ that is deformed into a circle?
I am trying to solve the 2013 paper set by ISRO for electrical engineers. I want some help to solve Question no 17 is correct.
So I don't even know how to approach the problem, what will be the new ...
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Single-line power transmission of 1MW over 35,000km [closed]
This question posted on the physics stack exchange has not received much attention. I thought the audience here might be more able to answer it.
Background
A space elevator is mechanism to provide ...
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