Coaxial end-launched and microstrip to partial H-plane waveguide transitions

Abstract

Conventional rectangular waveguides are commonly used for high power and other microwave and millimeter wave applications. Their use at lower frequencies has been limited by their bulky nature. A new type of compact waveguide called a partial H-plane waveguide has previously been proposed that has only one quarter of the cross sectional area of a conventional waveguide. However, only limited information relating to the feeding of such waveguides is available. This paper presents two types of transitions to partial H-plane waveguides from the coaxial and microstrip transmission mediums. Additionally, in the coaxial case the transition is end-launched to offer collinear properties. The development of both transitions is discussed and optimized designs presented with simulated and measured results over H-band (3.95–5.85 GHz).