5:15 PM - 6:45 PM
[PEM16-P04] Development of a wideband feed system for the solar and planetary radio telescope in Tohoku University
Keywords:Radio Telescope, Development, Sun, Jupiter
We have operated the Iitate Planetary Radio Telescope (IPRT) with a physical aperture area of over 1000 m2 since 2001. Currently, we are developing a new feed system to achieve higher sensitivity in a wider bandwidth for extending future solar-planetary and astronomical science objectives.
The current receiving system consists of two systems, one for narrowband high-sensitivity observations centered at 325 MHz (& 650 MHz: under development) and the other for broadband observations targeting the 150-500 MHz band. The former is used to observe Jovian synchrotron radiation or extrasolar objects such as pulsars, and the latter observe the spectra of solar radio bursts (the AMATERAS system). The practical bandwidth (aperture efficiency over 20%) of the AMATERAS system does not reach 200 MHz, so they have a weak point in terms of sensitivity for observing astronomical objects such as wide-band solar radio bursts and/or extra-solar sources to make future VLBI observations with the oversea facilities (ex. μGMRT, SKA…).
In order to improve the efficiency at the broadband feeds, we have started to develop a new feed system for the 100-700 MHz band with higher aperture efficiency. We set the target total efficiencies at more than 60% for the 325 & 650 MHz band, and at more than 40% for the all frequency band as tentative values. We have started the development using the electromagnetic(EM) field analysis software FEKO by adopting self-complementary sinuous antenna (c.f. de Villiers, 2017), which has been reported as a feed for the SKA-MID band-1. At present we try to adopt the pyramidal sinuous antenna with a flattened antenna element. The main challenge is to give the beam characteristics compatible with the rectangular parabolic surface of the IPRT. We plan to produce a small-scale feed model for evaluating its EM characteristics to identify issues for practical use in FY2024, and to implement a real scale feed to the IPRT in FY2025.
In this presentation, we will introduce the current status of feed system development with science targets expected to contribute from the realization of broadband observations.
The current receiving system consists of two systems, one for narrowband high-sensitivity observations centered at 325 MHz (& 650 MHz: under development) and the other for broadband observations targeting the 150-500 MHz band. The former is used to observe Jovian synchrotron radiation or extrasolar objects such as pulsars, and the latter observe the spectra of solar radio bursts (the AMATERAS system). The practical bandwidth (aperture efficiency over 20%) of the AMATERAS system does not reach 200 MHz, so they have a weak point in terms of sensitivity for observing astronomical objects such as wide-band solar radio bursts and/or extra-solar sources to make future VLBI observations with the oversea facilities (ex. μGMRT, SKA…).
In order to improve the efficiency at the broadband feeds, we have started to develop a new feed system for the 100-700 MHz band with higher aperture efficiency. We set the target total efficiencies at more than 60% for the 325 & 650 MHz band, and at more than 40% for the all frequency band as tentative values. We have started the development using the electromagnetic(EM) field analysis software FEKO by adopting self-complementary sinuous antenna (c.f. de Villiers, 2017), which has been reported as a feed for the SKA-MID band-1. At present we try to adopt the pyramidal sinuous antenna with a flattened antenna element. The main challenge is to give the beam characteristics compatible with the rectangular parabolic surface of the IPRT. We plan to produce a small-scale feed model for evaluating its EM characteristics to identify issues for practical use in FY2024, and to implement a real scale feed to the IPRT in FY2025.
In this presentation, we will introduce the current status of feed system development with science targets expected to contribute from the realization of broadband observations.