IEC 60153-4 Ed. 3.0 b:2017

IECA 60153-4:2017 specifies straight hollow metallic tubing of circular waveguides for use as waveguides in electronic equipment.
The aim of this recommendation is to specify for hollow metallic waveguides:
a) the details necessary to ensure compatibility and, as far as essential, interchangeability;
b) test methods;
c) uniform requirements for the electrical and mechanical properties.
This edition includes the following significant technical changes with respect to the previous edition:
a) expand and revise the operation frequency range for waveguides;
b) revise the allowance of aperture dimensions;
c) revise the test method for aperture dimensions;
d) revise the equation of attenuation.