Radio Frequency Engineering Advancements for the Ghana Radio Telescope

This paper presents recent radio frequency (RF) engineering work performed for the Ghana Radio Telescope, specifically concerning receiver and electromagnetic component design and analysis. An upgraded so-called Mark II receiver, currently nearing the end of its development phase, improves the bandwidth by approximately 100% and 30% for the 5 and 6.7 GHz bands, respectively. A proposed new wideband orthomode transducer (OMT) design is presented to replace the existing Intermediate Circular Orbit (ICO) satellite system components, which are known to add extra noise. Also contributing to the system noise temperature is the antenna and spillover temperatures. Electromagnetic simulation data is used to determine these parameters, showing that the antenna can contribute up to 32 K to the system noise temperature near the horizon. The resulting predicted sensitivity of the telescope is presented and is in the range of 4.6 to 5 m²/K assuming a receiver temperature of 90 K and an aperture efficiency of 70%.