Tagged Questions

A waveguide is a physical structure that guides electromagnetic or sound waves. They are most commonly employed at high frequencies such as microwave.

140 views

RF cable with DC power cable?

I have a satellite communication system at office running on C-band. The C-band is downconverted to L-band and carried to the l-band modem. With this RF coaxial waveguide/cable, +12V DC power cable ...
91 views

Coplanar waveguide vs open space?

I'm routing a U.FL connector to a cellular module (Telit GE864). According to this calculator a 1mm track with 0.16mm gaps should provide a 52Ω impedance path to an U.FL antenna connector. A ...
2k views

Why are rectangular waveguides not used for inter-city transmission?

Waveguides can transmit very high powers, isolating the signal from external noises and interferences. Besides, waveguides have a very low loss. These capabilities make them an interesting candidate ...
124 views

Impedance of waveguides shorter than 1/10 of wavelength

I read already several times that it is a common rule of thumb, that matching the impedance of a waveguide to the external network impedance is only necessary for waveguides longer than 1/10 of the ...
155 views

Waveguides: How can you propagate at only one frequency?

In a rectangular waveguide, we know we can find cut off frequency as a function of mode and geometry. Is there a way to design the waveguide so to ensure that we can limit the frequency of ...
93 views

Plane wave causing TE mode in waveguide

I've been struggling with a problem given to us during a exercise-session of waveguides. First part of the exercise was calculating the electric field inside of a waveguide in the form of 2 parallel ...
3k views

Why is it that a TEM mode propagates in a - Two separate conductor wave guide?

Please someone explain to me in Simple English or Basic equations as to why does a Transverse Electric and Magnetic Modes(TEM) propagate on only two surface Wave ...
739 views

Automatic impedance matching in microwave waveguides

I am trying to building a magnetron plasma using microwave magnetron. I now need to build magnetron to antenna link using rectangular waveguide, WR-340. I then found out that it needs to be tuned ...
236 views

How are modes generated in a waveguide?

Its related to my previous question Modes in waveguides I have a doubt that how are different modes actually generated? I mean in Digital and Analog communication, we studied how we modulate the ...
366 views

Why a wave does not enter a cable? Understanding TDR (Time Domain Reflectometry)

I have been doing some TDR (Time Domain Reflectometry) measures which involves sending gaussian pulses through a cable and measuring the s11 (reflection) parameter. In this measure, I could see that ...
823 views

Field Patterns in Waveguides

How are the field patterns for magnetic and electric field obtained using the field equations? What is the intuitive way of understanding and drawing them? I searched a lot regarding the method for ...
305 views

Reflection coefficient VS frequency

I was trying to look for the answer of what I think it should be quite a simple question but I haven't found any nice answer (at least any that has convinced me). Here it is: Through a cable (...
283 views

Modes in waveguides

What is the meaning of Modes in waveguide? With what physical property of the Electromagnetic wave does it deal with? I have just started with parallel plane waveguide and in that case the constant m- ...
304 views

Contact pad size for microprobe coaxial to planar waveguide transition

http://www.ggb.com/t-4.html Can someone explain what size one should choose at minimum/maximum for the pads and what role the pitch plays (besides impedance matching)? If I order a 100 micron tip ...
403 views

Tapering of planar waveguides

Can anybody recommend some literature or explain some rules of thumb for tapering planar waveguides? As I understand correct tapering is needed for example for bended waveguides or like in the picture ...
849 views

Differences between a planar coil and coplanar waveguide to create a local 1D AC magnetic field

Coplanar waveguides (for example picture look here) are often used in research to create a local in-plane magnetic field. Now if compared to a planar microcoil like this, driven by a AC voltage in ...
11k views

Connecting horn antenna to a gunn transceiver

I have a surplus Microsemi MO9072 24GHz gunn transceiver (Datasheet) and a matching MDT86552 horn antenna (Datasheet) that I'd like to use in a project. In the same package was a waveguide of some ...
703 views

Simulation software to terminate planar waveguides by geometry and material choice?

There are a lot of electromagnetics software modeling suites out there (HFSS, CST Microwave, Sonnet some I've heard of). I want to terminate a coplanar GS or GSG waveguide with 50 ohm. I know that ...
193 views

Impedance calculators differ pretty much?

As you can see here to calculators I found show huge difference or didn't I set it up correctly? I didn't found hints on possible validity limits. Can someone say if one of those given out results is ...
2k views

How to terminate a coplanar waveguide with 50 ohm load?

So I want to structure a coplanar waveguide by lithography, VNA - coaxial - picoprobe - coplanar waveguide transition to measure impedance of the waveguide. As signal and ground lines are on one ...
3k views

Can I improve the directivity of an X-band radar module with integrated plane-patch antenna?

Lots of detail provided in case it's needed. I'm continuing to tinker with remote proximity sensors driven by an Arduino (and eventually just an ATMEGA* chip and its safety buddies) and have a pretty ...