IF System

Introduct

The Array for Microwave Background Anisotropy (AMiBA) is an array comprised up to nineteen small radio telescopes. The conventional LO system first generates the 14GHz signals from a 100MHz signal source. These signals are then distributed to each radio telescope by coaxial cable. The required 42GHz LO signal is generated by a tripler and then amplified to feed the mixers. The phase switching is done by two solid state single-pole four-throw switches and delay lines at 14GHz.

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 15, 30, 45, 60 degree @14GHz
Phase Switching Rate 5MHz (max.)
IF gain 30dB
IF Transmission Line Length 5m

fig.1:Schematic of phase switching module
fig.2:Schematic of LO generation and distribution
fig.3:Schematic of YIG oscillator
fig.4:Schematic of on-board unit at each receiver
fig.5:Schematic of LO modules