<italic>Q</italic>-Band Radial Waveguide Power Divider Based on a Specific Cycloidal-Like Transition Implementation

Abstract

An axially symmetric radial waveguide power divider, which utilizes a specific Cycloidal-Like tapered transition between a central coaxial launcher and a radial waveguide, is presented in this paper. In order to broad the operation band, the change of impedance of the coaxial to radial waveguide transition is investigated, and an analytic expression for the shape of the transition is obtained. A simple electromagnetic modeling for the stepped radial matching network is developed, and its characteristics are analyzed in detail using the circuit method. Eventually, a stepped-by-stepped design procedure for the power divider is established for the design of the radial waveguide power divider. A twenty-way radial waveguide divider is designed, fabricated, and measured to validate the proposed method. The measurements show that the return loss at the input port is better than 20 dB over almost the full ${Q}$ -band (33 to 48 GHz), while the amplitude/phase imbalance are within ±0.5 dB and ±3°, respectively. The simulated and measured results demonstrate a high degree of agreement.

Keywords

• Broadband
• coaxial waveguide
• power divider
• radial waveguide
• taper transition