The leaky-wave antennas are characterized by a complex propagation constant kt = βt − jαt with |βt| lower than k0, the free space propagation constant. The leaky-wave mode then travels in the guiding structure faster than the speed of the light and at the same time it leaks energy in reason of the attenuation constant αt. In the lossless case, this energy is totally radiated by the structure and so the leaky-mode couples the guided power into free space. On the other hand, traveling wave antennas that support surface waves, like surface wave antennas, radiate power flow from discontinuities in the structure that interrupt the bound wave on the antenna surface. The different radiation mechanism has direct effect on the mismatch problems of the two structures. Those problems are normally encountered either at the transition from the feeding mode to the traveling mode or at the end of the structure.

Focusing on the leaky-wave antennas, it is worth noting that the leaky mode is normally a small degradation of the feeding mode coming from the feed and then no mismatch problems are found at this point. Moreover, as already addressed introducing the radiation mechanism of these antennas, the leaky mode leaks power traveling along the structure and then an insignificant amount of power is left by the time the wave reaches the end of the structure. Even if reflected, this vestigial power cannot cause any serious mismatch problem. Consequently normally leaky wave antennas, if adequately fed, do not present any mismatch problem, in contrast with the case of surface wave antennas where both the feed and the end termination can pose serious design problems.

@khalid Alhussaini , Does it help in noise supression?

A leaky wave cable is interesting for e.g. tunnels or underground installations. It is easy to deploy and shape in the right form. I can also imagine that the field will be more constant than in case of an antenna, where the field will be significantly higher close to the antenna and weaker e.g. around a bend in a tunnel. But that is just an assumption.

I can think of some applications where a leaky cable might be better than an antenna- distributing RF power on a tunnel (subway communication they usually employ leaky cables), to illuminate an area where RFID tags are present (for instance inside a refrigerator or in a storage area). I like to see the leaky cable as a conduit where you can locally distribute RF power, like a hose with several drilled holes people use in gardens .

Care must be taken because usually these cables are poor radiatiors, so its much more a near field thing than actually a "real" antenna.

Thank you sir for sharing useful information regarding LWC.

My project is to find Channel State Information of multiple rooms using dedicated transmitters at each room and one leaky wave cable as receiving antenna for all rooms.

i have successfully done that.

Can you please indicate what technical advantages can Leaky Wave Cable give me when I use it as a receiving antenna instead of using dedicated antennas for each room?

I would really appreciate your answer.

Aziz

I can think of a field coverage in the are where you deployed your system (simulation or measurement, since yove done the project in real world). You measure the fields you get in the area and then compare with the case of antennas. For the antennas, since you dont have them, simulation can be used (Friis formula may be applied, as a first order approximation).

Just an idea, might be other ways to prove the superior performance of the leaky cable.

@marcelo B.Perotoni Can you please mentioned other ways to prove superior performance of LWC?

Since you want illuminate an wide area, it would involve the power in vs power out for both cases, probably showing a table with the costs of both solutions.

You can use antennas to get the same effect though I suspect there would be way too many, rendering this option too expensive.

I cant think of other parameter of comparison...

@ Marcelo B.Pertoni  Sir is leaky wave cable more robust to interference than an antenna? If yes then how?