Loss Calculations for Rectangular Coupled Bars (Correspondence)

By using slope information obtained from Getsinger's or Gupta's charts, it is possible to calculate incidental loss in TEM coupled-line sections using the equation for /spl alpha//sub cc/ given in this correspondence. This value of loss factor can then be used to calculate incidental loss in components that include coupled-line sections for which Z/sub 0//sup 2/ = Z/sub 0e/Z/sub 0o/, such as 90/spl deg/ backward-wave couplers and microwave C sections. An example calculation is given for a single-section 90/spl deg/ coupler.