Two Co-Linear Transitions for Q-Band Horn Waveguide Dense Cluster

This paper presents the design of two in-line transitions operating in Q-band for radioastronomy or satellite applications. Both employ the WR-22 rectangular waveguide. The first transition involves as end-launcher a microstrip line, the second a coaxial cable. Focus of the works is to obtain a design which simplifies the geometrical configuration by keeping a reasonable compactness and without affecting the transversal space occupation, while ensuring a good matching (return loss higher 24 dB in both cases). The performance are evaluated in terms of scattering parameters.