Experimental investigation into the design of spatial power combining in nonradiating dielectric (NRD) waveguide

Abstract

The project involves the design and construction of amplifier circuits within a Nonradiating Dielectric (NRD) Waveguide. These circuits are integrated in an NRD environment with the aim of achieving spatial power combining in the frequency range of 8 GHz to 10 GHz. Tapered slotline antennas receive the input signal and transmit the amplified signal. The input and output of the amplifier modules are connected to the slotline antennas via microstrip-to-slotline transitions. The circuit boards are inserted into slots in the dielectric of the NRD waveguide. Measurement results for a prototype revealed some mode conversion from NRD mode to TEM mode, resulting in loss through radiation. Further investigations were carried out using commercial software. In order to solve the problem, a modified structure was proposed. In this structure, NRD waveguide to dielectric-filled waveguide transitions are introduced. The amplifier circuits are then placed in the dielectric-filled waveguide section to avoid radiation. Simulated and measurement results of this structure are also presented.