SELF-PHASING RADIO TELESCOPE ARRAYS,
CENTER FOR RADIOPHYSICS AND SPACE RESEARCH CORNELL UNIV ITHACA N Y
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A system which produces a self-phasing radio telescope array is shown. The system has features which permit its application to very extended arrays, and provide for multiple beams. It consists of a reference antenna and associated electronics, to whose signal output all other antenna outputs will be compared and phased. One such slave element is shown. A superheterodyne circuit is shown although this is not necessary, it is by far the simplest to construct at present. The phase adjustment of the slave element is performed in a standard phase locked loop in which the IF outputs of the references and slave element are compared in a phase detector. The output of this phase detector is a varying DC voltage which is used to control the phase and frequency of a voltage controlled oscillator VCO which is the local oscillator of the slave element receiver. The VCO can be similar to the usual crystal controlled oscillator, in which the control voltage is applied to the crystal to pull the frequency and phase as required. In operation, the phase locked loop works upon the VCO so as to insure cophasing of the IF signals of reference and slave element at the central comparison point, which would normally be the central data gathering point of the array.
- Electrical and Electronic Equipment