Local Oscillator System

Introduct

The prototype LO module contents two units, namely oscillator unit and multiplier unit. The oscillator unit is designed to provide enough power and frequency stability at 21GHz for the multiplier unit. The multiplier unit is designed to provide enough power level at 42GHz for the subharmonic mixer. The phase switching is done by two solid state single-pole two-throw switches and delay lines at 21GHz. The IF modules contain wideband amplifier and equalizer to transmit the downconverted IF signal to the correlator module.

Specifications of LO and IF modules for AMiBA


LO Frequency 42 GHz (fixed)
LO Power Level (min. value to each Receiver) 13 dBm
LO Noise Level -151.27dBc/Hz
Phase Noise 10-6 (<5degree)
Phase Switching Type 0, 45 degree @21GHGz
Phase Switching Rate 5MHz (max.)
Cable Length accuracy 1mm level


Block Diagram of prototype LO module

 

Design of prototype multiplier unit
Design of prototype oscillator unit