A 64 Element Phased Focal Plane Array for 70 – 95 GHz
By Neal Erickson (UMass-Amherst)
UMass and BYU are building a 64 element phased array receiver for use in the focal plane of the GBT, in the frequency range 70-95 GHz. These receivers offer the potential to synthesize up to four times more beams than there are elements, and to measure and correct large scale telescope surface errors. There are many unique challenges with building such a receiver at short wavelengths, and in applying it at the Gregorian focus.
The talk will discuss the theory of beamforming with the array and the results of simulations of feed efficiency. This receiver uses cryogenic MMIC amplifiers in the front end followed by room temperature amplification and mixing, requiring several innovations in construction.
These unique features will be described, as well as the layout of the backend beam summing and calibration network.
