Samuel López Ruiz

This paper presents the design of a feed system at K and Q frequency bands which permits simultaneous observation at a radio telescope. The system will be used for radio astronomical VLBI applications. With this design we get simultaneous operation with two different cryogenical receivers placed at the focal zone of the radio telescope with a relative pointing error lower than 3arcsec and an aperture efficiency higher than 75%. Quasi-optical techniques have been used to implement a frequency… Mostrar más

This paper presents the design of a feed system at K and Q frequency bands which permits simultaneous observation at a radio telescope. The system will be used for radio astronomical VLBI applications. With this design we get simultaneous operation with two different cryogenical receivers placed at the focal zone of the radio telescope with a relative pointing error lower than 3arcsec and an aperture efficiency higher than 75%. Quasi-optical techniques have been used to implement a frequency independent system. Phase corrected feeds have also been developed in order to reduce the size of the feeds and to allow cooling down and receiver noise temperature improvement. The design has been validated with laboratory test and on site tests after positioning and alignment at the focal zone of the 40 meter Yebes Observatory radio telescope. Mostrar menos

This paper presents the design of a feed system at K and Q frequency bands which permits simultaneous observation at a radio telescope. The system will be used for radio astronomical VLBI applications. With this design we get simultaneous operation with two different cryogenical receivers placed at the focal zone of the radio telescope with a relative pointing error lower than 3arcsec and an aperture efficiency higher than 75%. Quasi-optical techniques have been used to implement a frequency… Mostrar más

This paper presents the design of a feed system at K and Q frequency bands which permits simultaneous observation at a radio telescope. The system will be used for radio astronomical VLBI applications. With this design we get simultaneous operation with two different cryogenical receivers placed at the focal zone of the radio telescope with a relative pointing error lower than 3arcsec and an aperture efficiency higher than 75%. Quasi-optical techniques have been used to implement a frequency independent system. Phase corrected feeds have also been developed in order to reduce the size of the feeds and to allow cooling down and receiver noise temperature improvement. The design has been validated with laboratory test and on site tests after positioning and alignment at the focal zone of the 40 meter Yebes Observatory radio telescope. Mostrar menos

This paper presents the design of a tree sections corrugated horn antenna with a modified linear profile, using NURBS, suitable for radio-astronomy applications. The operating band ranges from 4.5 to 8.8 GHz. The aperture efficiency is higher than 84% and the return losses are greater than 20 dB in the whole bandwidth. The antenna optimization has been carried out with multiobjective versions of an evolutionary algorithm (EA) and a particle swarm optimization (PSO) algorithm. We show that both… Mostrar más

This paper presents the design of a tree sections corrugated horn antenna with a modified linear profile, using NURBS, suitable for radio-astronomy applications. The operating band ranges from 4.5 to 8.8 GHz. The aperture efficiency is higher than 84% and the return losses are greater than 20 dB in the whole bandwidth. The antenna optimization has been carried out with multiobjective versions of an evolutionary algorithm (EA) and a particle swarm optimization (PSO) algorithm. We show that both techniques provide good antenna design, but the experience carried out shows that the results of the evolutionary algorithm outperform the particle swarm results. Mostrar menos