| 摘要 |
PURPOSE:To improve ease of processing without losing the electric characteristic by forming four corners of cross section of a chamferred waveguide in the form of circular arc and designing each dimension so that the cut-off wavelength and the characteristic impedance are made equal to those of a conventional rectangular waveguide. CONSTITUTION:The cut-off wavelength lambdac2 of the waveguide is expressed as lambdac2=2a2[1-K(r/a2)<2>] by the perturbation method, where the lambdac2 is supposed to be sufficiently smaller in comparison with a long side a2, b2 is the size of a short side and (r) is a radius of the circular arc at four corners in the cross section of the waveguide. The establishment of the relation of 2a1=2a2[1-K (r/a2)<2>] is the necessary and sufficient condition in order to make the wavelength lambdac2 equal to the cut-off wavelength lambdac1 of the waveguide having the inside long side a1 and short side b1, where K is a value of 1<=K<=4 practically. The (r) is a half the size of the short side, and the characteristic impedance of both the waveguides is made qual in this case with the relation of b2/a2=b1/a1. |
