2018年4月30日 · The PAF’s computer and signal processors can calculate up to seven point-spread functions at a time, enabling the receiver to synthesize seven individual beams on the sky. The new design also allows these regions to overlap, creating a more comprehensive view of the region of space being surveyed.

Test of PAF Backend Amplitude and Noise Linearity: Test_of_PAF_Backend_Amplitude_and_Noise_Linearity.docx; TOPICS FOR AN UPGRADED PAF, DECEMBER 2014. System block diagram: https://safe.nrao.edu/wiki/bin/view/Beamformer/SystemArchitecture; Next generation cryogenic low noise amplifier; Coaxial input lines; Digital down converter; Net Burner info

Abstract—A low-noise cryogenic phased array feed (PAF) is in development for the Green Bank Telescope (GBT). The feed consists of electrically small elements tuned to operate near 1.4 GHz and optimized for active impedance matching to cooled front end low noise amplifiers (LNAs).

NRAO的中央开发实验室的PAF小组负责人Bill Shillue说：这个项目汇集了一种最先进的、低噪音的接收机设计、下一代多通道数字 无线电技术 ，以及先进的相控阵建模和波束形成。

Understanding the noise, efficiency, calibration, and RFI mitigation properties of an uncooled array is a key step toward a PAF whose individual beams have noise temperatures similar to the best single-beam receivers.

2013年4月1日 · 19-element dual-polarization phased array feed (PAF) for L-band with cryogenic SiGe HBT LNAs. Measured Tsys of 35K on the Green Bank 20-meter telescope. This PAF will be tested on the GBT in early 2013.

To accelerate the pace of discovery and exploration of the cosmos, a multi-institution team of astronomers and engineers has developed a new and improved version of an unconventional radio-astronomy imaging system known as a Phased Array Feed (PAF).

This is a Phased Array Feed (PAF) for the Green Bank Telescope. It is put at the prime focus of the GBT. Each of the flanges is a crossed dipole antenna. There are 19 of these crossed dipoles. Their signals are sent to a digital signal processor which combines the signals from the 19 elements to form a single radio beam.

We will emphasize a reusable and scalable PAF architecture that will take advantage of the continuously decreasing costs of signal processing, thereby assuring a steadily increase in the NbB product.

• NRAO is working on key technologies and collaborating wit partner instituions to advance Phased Array R&D • The goal is to demonstrate: – Low-noise PAF receivers – Efficient electronics and signal processing – Accurate Modeling – Science demonstrators . So that PAF can be a viable choice for future radio astronomy instruments