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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What is the physical meaning of the dispersion equation of an antenna?
I have a basic doubt about the role of the dispersion equation of an antenna. There are many situations (grounded dielectric slab, optical fibers etc) in which it is written, so I will put here an ...
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Can a metallic rectangular waveguide support hybrid modes?
Studying the basics of guided waves in metallic rectangular waveguides, filled with homogenous dielectric material, I see that there is always a distinction between TE and TM modes. I understand that ...
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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 Dominant Mode in a Circular Waveguide
I was doing the analysis of a circular waveguide (precisely, a wave guide with half - circular section of radius a, as shown in the following picture, and in which the shell is a Perfect Electric ...
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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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Interface Conditions between Dielectrics inside a Waveguide
let's consider a general waveguide with two ideal dielectrics inside it:
Let's consider the interface condition about the tangential electric field:
Generally E = E(x,y,z), where z is the axis of ...
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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 50Ī© 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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409 views
Differential Pair Reference Plane Coupling
I am routing LVDS pair on a flex board. The signal is 264MHz. I used Saturn PCB design to calculate width and spacing between conductors. The targeted impedance for diff pair is 100 ohms, which is ...
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Coplanar Waveguide Calculations PCBS, AppCAD v.s. Online calculators
So lately I noticed that the Coplanar Waveguid calculations of AppCAD (http://www.hp.woodshot.com/) did not give the same result as the online calculators do.
https://chemandy.com/calculators/...
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Frequency response of the waveguide
So, I have signal in the waveguide that is transmitted by two modes of radiation, for which the delay is for example \$\tau_1=6\,\text{ns},\, \tau_2=6.5\,\text{ns}\$, respectively. And the energy ...
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Design of cavity filter
I try to design a Chebyshev bandpass filter for 6 GHz as a coaxial cavity filter. I know that the filter can be designed with the aid of the coupling coefficients between the resonators and the loaded ...
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Metallic Waveguide Boundary
I've been studying TE and TM modes on waveguides for microwave frequencies.
It basically consists on applying Maxwell equations on a rectangular metallic cavity, with infinite length on \$z\$ ...
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Standard 2.54/1.27mm pinheader impedance
Note
I turned my answer into something of a collection of free impedance calculators..
I was thinking of using one of the most ubiquitous connectors in the world - 2.54mm pin header. The snag here is ...
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Can I trust these microwave power readings?
So I've got an old Hughes TWT that supplies roughly 20W across the Ku band (12.4 - 18 GHz) that has a waveguide output flange (WR-62). I am "gently re-purposing" it to be driven at a lower frequency (...
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169 views
Rectangular Waveguide H-Plane Step Discontinuity - Equivalent Reactance for Change in Height
I have been reading Pozar's Microwave Engineering, and in Section 4.6, he goes through the analysis to determine the reactance of a discontinuity between two coupled waveguides. In that chapter, he ...
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Phase and group velocity of wave
When an electromagnetic wave enter the waveguide, what is the change in the phase and group velocity that happen in waveguide?
Does wavelength or frequency of wave change when it enter the wave guide?...
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Analysis of transmission lines and waveguides
While reading the transmission lines in electromagnetic field theory , I observed that while analyzing different transmission lines like co-axial cable, and two wire lines, we are using the electric ...
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Antenna CPW internal layer
I see on the internet showing CPW( coplanar waveguide) always placed on TOP layer with ground underneath. This is what I usually do.
Is it possible to place a CPW in an internal layer? if so what ...
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Scattering parameters of a phase shifter
I connected a phase shifter to a VNA and measured S11 and S21. Upon setting the angle (phase) to a 100 degrees and measuring the phase of S11 I obtained the following graph, whereas theoretically S11=...
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What makes the band of an antenna broader than others?
Even though I'm studying waveguide slot antennas, so the examples that I'm going to give are related to this topic, my question covers a wider range of topics.
I already know about a couple of things:...
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Designing a 50Ī© coplanar waveguide on 1.6mm FR4
I'm trying to design a 50Ī© coplanar waveguide to connect the output of a LoRa module to a SMD metal antenna. The two images below show the top layer (red) and bottom layer (blue). Vias are green and ...
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Waveguide with 3 dielectric sections
The cross sectional dimensions of the rectangular waveguide in the figure are
\$a=50 mm, b=25 mm\$. The waveguide consists of 3 sections filled with dielectric materials such that the relative ...
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Waveguides question
A rectangular waveguide with dimensions \$a=10cm, b=6cm\$ is filled with dielectric material with an unknown relative coefficient \$\epsilon_r\$. The guide is terminated by an unknown load. It is ...
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What are the waveguide modes of twisted pairs as discussed here?
From the recent Lightwave article ASSIA exec touts terabit-speed DSL:
In a keynote address delivered earlier this week at the G.fast Summit in Paris, Dr. John Cioffi, chairman and CEO of DSL ...
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Microwave Waveguide Power Ratio
Had a waveguide system set up similar to picture, to compare measured to calculated power ratio or path loss (differences between positions). With an SWR meter the following was recorded at various ...
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Can closed metal box work as a wave-guide for wireless transmitter?
I am using NRF24L01 and ZigBee modules for wireless communication. I kept the modules in the tapered closed aluminum cylinder for sensor data transmission. The signal was being received when the ...
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What is the simple meaning of TE10 waveguide [closed]
What does this numeral 10 represents and why do we have TE10 TE11 and then TE20. Where are the rest?
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Coplanar waveguide - Calculator question
I was looking for information on coplanar waveguides (curiosity prompted by another question here) and found this calculator.
In the description of use, it mentions that the units for the dimensions ...
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1answer
367 views
Microwave Waveguide system tuning
I am going to built microwave system with following system configuration.
Power Circuit -> Magnetron -> Wave Guide Coupler -> Isolator -> 3 Stub Tuner -> Applicator.
Now, I want to make 3 Stub ...
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55 views
Group velocity dispersion for coupled waveguide system
I am an EE undergrad currently studying group velocity dispersion (GVD) for coupled waveguides, and am quite confused on the following question: how do you characterize group velocity dispersion for a ...
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Why is Kapton film used to hold liquid in waveguide?
I am working on a project similar to the one described in this paper
MEASUREMENT OF COMPLEX PERMITTIVITY OF LIQUIDS.
Here a Kapton film is used to hold liquids, so that they don't spill. Why is this ...
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What are the advantages of CPW over microstrip?
I have to use a coplanar waveguide (CPW) for a project which is going to characterise small amounts of tissue. I have never used CPW before.
What are the advantages of using CPW? What would be some ...
