Optical counterpart of duckbill check valve in fluid dynamics

[qnach]

In fluid dynamics there is a duckbill check valve to prevent the reverse flow.
In EM wave an antenna emmits/receive at the same efficiency.
Is there anyway one can make a check valve for antenna so that it emmits more than received or
vice versa...or perhaps emitts without even receive?

 

[deskswirl]

I think you mean a faraday rotator https://en.wikipedia.org/wiki/Faraday_rotator

 

[qnach]

I think you mean a faraday rotator https://en.wikipedia.org/wiki/Faraday_rotator

Yes, that is one possibility, which requires an externally applied magnetic field.
Is there any way that we can achieve the same purpose without external magnetic field?
For instance, the material might change shape or rotate if it received EM wave in one direction hence cause the EM wave flow in the other direction impossible?

 

[Baluncore]

There are many ways of making a non-reciprocal coupler.
1. The microwave circulator; https://en.wikipedia.org/wiki/Circulator
2. The TR switch used in a Radar; https://en.wikipedia.org/wiki/Duplexer
3. The “180° Hybrid Coupler” “Ring”, “Ratrace”, or “Magic-T”.
https://www.microwaves101.com/encyclopedias/hybrid-couplers
Consider connecting the antenna to one terminal, then the RX and the TX to adjacent terminals λ/4 away on each side of the antenna terminal. The RX and TX will be unable to see each other but both will see the antenna.

 

[qnach]

There are many ways of making a non-reciprocal coupler.
1. The microwave circulator; https://en.wikipedia.org/wiki/Circulator
2. The TR switch used in a Radar; https://en.wikipedia.org/wiki/Duplexer
3. The “180° Hybrid Coupler” “Ring”, “Ratrace”, or “Magic-T”.
https://www.microwaves101.com/encyclopedias/hybrid-couplers
Consider connecting the antenna to one terminal, then the RX and the TX to adjacent terminals λ/4 away on each side of the antenna terminal. The RX and TX will be unable to see each other but both will see the antenna.

The third method (above) seems to be a special case for the first one?

 

[Baluncore]

The third method (above) seems to be a special case for the first one?

That may be true if you look at it from a purely analytic viewpoint, but you need to also consider the physical implementation and wavelength. Microwave circulators with waveguides, ferrite and magnets are not built for the HF band. The “Ratrace” can be built with long coaxial cables for operation on the HF bands. I am sorry about the duplication.

 

[qnach]

That may be true if you look at it from a purely analytic viewpoint, but you need to also consider the physical implementation and wavelength. Microwave circulators with waveguides, ferrite and magnets are not built for the HF band. The “Ratrace” can be built with long coaxial cables for operation on the HF bands. I am sorry about the duplication.

For the circulator, what are the differences for 3, 4, 9, or perhaps 16 ports? Do they exits with different phase and hence different cancellation?

 

[Baluncore]

Anything can be built if needed, but microwave engineers are conservative and so tend to use the the many three port circulators that are available as off-the-shelf components. The microwave circulator connected as an isolator is the closest equivalent to a “check valve”. Where a three terminal circulator is used as an isolator, two can be used in series to square the isolation ratio.

Trees of hybrid transformers or transmission line transformers are assembled to make multi-port distributors and combiners. An arbitrary phase shift can be generated by using appropriate length transmission lines and transformers.

 

[Baluncore]

The optical equivalent of a check valve would be an optical isolator; [PLAIN]https://en.wikipedia.org/wiki/Optical_isolator[/PLAIN]
https://en.wikipedia.org/wiki/Optical_isolator

A partially reflective diagonal mirror can be seen as a combiner of two isolated inputs, that generates two outputs.

 

[qnach]

For the circulator, should the wave come from its side wall? Or, does not matter?

 

[Baluncore]

For the circulator, should the wave come from its side wall? Or, does not matter?

I do not understand the question.
What type of circulator? at what wavelength? what type of transmission line? which wave? Both walls are side walls, I guess it will depend on mode of propagation.

An EM wave in a waveguide is guided by the conductivity of the walls. Current flows in the walls, but the EM wave fills the inside volume of the guide.

 

[qnach]

I do not understand the question.
What type of circulator? at what wavelength? what type of transmission line? which wave? Both walls are side walls, I guess it will depend on mode of propagation.

An EM wave in a waveguide is guided by the conductivity of the walls. Current flows in the walls, but the EM wave fills the inside volume of the guide.

By a circulator I mean
https://en.wikipedia.org/wiki/Optical_circulator

 

[qnach]

Is there three dimensional circulator, like a ball?

A circulator like http://science.sciencemag.org/content/343/6170/516
or those used in microwave engineering is in general a cylindrical shape.
But is there a 3-D shape ones?

 

[Baluncore]

For microwaves, the waves are traveling between the walls of the waveguides. Since the EM transmission mode is important, the orientation of the ports need to be related. The perpendicular magnetic field requires the planar solution. The Magic-Tee is a four port coupler that requires perpendicular arms. [PLAIN]https://en.wikipedia.org/wiki/Magic_tee[/PLAIN]
https://en.wikipedia.org/wiki/Magic_tee

In optical-isolators the polarisation is also important, as the light passes through transparent materials with anisotropic properties that rotate the polarisation in a controlled way.

Before you invent a spherical circulator you need to consider the perpendicular nature of the electric, magnetic and poynting vectors. You then need to apply the “Hairy Ball Theorem” to see why the ring structure and not the sphere is used; [PLAIN]https://en.wikipedia.org/wiki/Hairy_ball_theorem[/PLAIN]
https://en.wikipedia.org/wiki/Hairy_ball_theorem

 

[qnach]

For microwaves, the waves are traveling between the walls of the waveguides. Since the EM transmission mode is important, the orientation of the ports need to be related. The perpendicular magnetic field requires the planar solution. The Magic-Tee is a four port coupler that requires perpendicular arms.
https://en.wikipedia.org/wiki/Magic_tee

In optical-isolators the polarisation is also important, as the light passes through transparent materials with anisotropic properties that rotate the polarisation in a controlled way.

Before you invent a spherical circulator you need to consider the perpendicular nature of the electric, magnetic and poynting vectors. You then need to apply the “Hairy Ball Theorem” to see why the ring structure and not the sphere is used;
https://en.wikipedia.org/wiki/Hairy_ball_theorem

So, in view of the hairy ball theorem, the conclusion is 3-D circulator is impossible?

 

[Baluncore]

So, in view of the hairy ball theorem, the conclusion is 3-D circulator is impossible?

That depends on your definition of 3D. The hairy ball suggests a torus rather than a sphere.

 

[qnach]

That depends on your definition of 3D. The hairy ball suggests a torus rather than a sphere.

Is there any textbook explicitly calculate the irreversibility of a 3-port (or any port) circulator?
or discussed similar devices?

 

[Baluncore]

There are many advanced books available. Analysis of microwave junctions is often done using the multi-port “scattering matrix”, with frequency dependent parameters S11, S22, S12, S21, S31, etc.

There is probably a beginners guide to circulator design in most general textbooks on microwave technology. You need a good technical engineering library.

The publisher “Artech House” produces books in that field. Search their titles, then the web or local technical libraries.
Do you have a big second hand bookshop in your city?

There are second hand books available if you know what you want. Use; http://www.bookfinder.com/
If you find what you want, try to support the Physics Forums website by buying through;
https://www.physicsforums.com/threads/support-pf-buy-on-amazon-com-from-here.473931/

 

[qnach]

There are many advanced books available. Analysis of microwave junctions is often done using the multi-port “scattering matrix”, with frequency dependent parameters S11, S22, S12, S21, S31, etc.

There is probably a beginners guide to circulator design in most general textbooks on microwave technology. You need a good technical engineering library.

The publisher “Artech House” produces books in that field. Search their titles, then the web or local technical libraries.
Do you have a big second hand bookshop in your city?

There are second hand books available if you know what you want. Use; http://www.bookfinder.com/
If you find what you want, try to support the Physics Forums website by buying through;
https://www.physicsforums.com/threads/support-pf-buy-on-amazon-com-from-here.473931/

Hey, just give me a reference like J. Kraus, Antenna, Chapter 5.
You don't need to care whether is it advanced or not, nore do you need to care whether do I have a good technical engineering library...etc.

 

[Baluncore]

http://www2.electron.frba.utn.edu.a..._Engineering_David_M_Pozar_4ed_Wiley_2012.pdf

https://ecedmans.files.wordpress.com/2014/10/microwave-devices-and-circuits-samuel-liao.pdf

http://www.radfiz.org.ua/share/shev...undations%20for%20Microwave%20Engineering.pdf

 

[qnach]

http://www2.electron.frba.utn.edu.a..._Engineering_David_M_Pozar_4ed_Wiley_2012.pdf

https://ecedmans.files.wordpress.com/2014/10/microwave-devices-and-circuits-samuel-liao.pdf

http://www.radfiz.org.ua/share/shev...undations%20for%20Microwave%20Engineering.pdf

I saw in Collin's book discussed non-reciprocal/Lorentz reciprocal theorem and in chapter 6 3-port circulators.
The other two books did not find similar topics (perhaps I missed them)
Collin's book is the classical one, I remember I bought one but sold it because I did not need that at that time...
The link of PDF file you gave has some problem for the mathematical symbols...I will try to find other one...

 

[Baluncore]

Is there any textbook explicitly calculate the irreversibility of a 3-port (or any port) circulator?
or discussed similar devices?

You need to be more precise in your question. Reversibility or reciprocity?

How can you calculate irreversability? Either you compute the rejection ratio of a real circulator, or you somehow prove that an ideal circulator can be nonreciprocal.

A circulator can be synthesised from one or more two port gyrator networks.
A three port circulator is the minimum nonreciprocal junction.

 

[qnach]

You need to be more precise in your question. Reversibility or reciprocity?

How can you calculate irreversability? Either you compute the rejection ratio of a real circulator, or you somehow prove that an ideal circulator can be nonreciprocal.

A circulator can be synthesised from one or more two port gyrator networks.
A three port circulator is the minimum nonreciprocal junction.

Thanks, I think I am talking about reciprocity.
I am trying to get some books you mentioned.
Is there any book on optical-fiber talking about such business?
Those three above are on microwave Engineering.

 

[Baluncore]

Is there any book on optical-fiber talking about such business?

Available books on the subject are very hard to find.

Download this .pdf from IOPscience, it refers to other papers on page 1.
"Magneto-optical non-reciprocal devices in silicon photonics", Yuya Shoji and Tetsuya Mizumoto.
http://iopscience.iop.org/article/10.1088/1468-6996/15/1/014602/pdf

 

[qnach]

Available books on the subject are very hard to find.

Download this .pdf from IOPscience, it refers to other papers on page 1.
"Magneto-optical non-reciprocal devices in silicon photonics", Yuya Shoji and Tetsuya Mizumoto.
http://iopscience.iop.org/article/10.1088/1468-6996/15/1/014602/pdf

So, is there any difference for microwave and optical device for a circulator?

 

[Baluncore]

So, is there any difference for microwave and optical device for a circulator?

There are conceptual and physical parallels in mode, polarisation and the control of phase shifts.
At the systems level, the scattering matrices and the synthesis of networks are the same.
The technology differs in wavelength and therefore in material selection and fabrication.

 

[qnach]

That depends on your definition of 3D. The hairy ball suggests a torus rather than a sphere.

How about an object with D3 symmetry...
Like this

https://en.wikipedia.org/wiki/Molec...:Delta-tris(oxalato)ferrate(III)-3D-balls.png

 

[Baluncore]

Any single torus or loop can be combed, but where one torus merges with another there will be problems. Your example has a central sphere where three separate loops combine. Each of those loops has two independent outer spheres with double bonds. So the purple and black hairy spheres cannot be combed and so will have combing problems where the EM waves meet.

It is your definition of 3D in post #13 that you must refine before your question can be answered.

 

[qnach]

Which book (on optics) can I find talking about Faraday rotator?

 

[Baluncore]

I have no single answer to that question. It will depend on your current understanding and what the application is that needs you to understand Faraday Rotation. Maybe you need to look for a book on electro-magnetics. Browse a library to find the next book you need, or visit a collection like; ht tp://inis.jinr.ru/sl/index00.html
Google 'faraday optical rotation'
Google BOOKS 'faraday rotation'