What is a waveguide coaxial adapter？

What is a waveguide coaxial adapter

1.waveguide coaxial adapter 

The waveguide coaxial adapter is usually a coaxial connector at one end and a waveguide flange at the other end, and the two ends are at a 90 degree Angle. The 90-degree Angle is because the central conductor of the coaxial connector acts as a probe into the waveguide, coupling the electromagnetic energy between the coaxial TEM transmission mode in the coaxial connector and the waveguide mode in the waveguide. The coaxial connector center conductor probe is inserted into the rectangular waveguide so that it is perpendicular to or parallel to the maximum electron field of the rectangular waveguide TE10 mode. The depth and geometry of the probe are designed so that the electromagnetic field radiated or coupled to the waveguide is optimized and higher order waveguide modes are avoided.

2.Advantages of a waveguide coaxial adapter

The waveguide flange of the waveguide coaxial adapter is also a short-circuit plate, and its wavelength is only a quarter of the center frequency of the waveguide, which can ensure that the radiation is only in one direction.
Since coaxial interconnects tend to have lower power processing than waveguides at the same frequency, it is important to note that coaxial interconnects can be a limiting factor in power processing for waveguide coaxial adapters. In addition, since waveguides are "banded," meaning that they have an upper band and a lower frequency band, while coaxial transmission lines have only a frequency upper limit, then the waveguide will likely be limited to the lower frequency of the waveguide coaxial adapter.