The APERTIF Phase Locked Loop (PLL) Unit

© ASTRON, 2014

Just some impressions of the APERTIF Phase Locked Loop Unit (PLL) which was installed in radiotelescopes 2 and 5 at the Westerbork site on June 24th.

The PLL is a vital part of the Local Oscillator Generation system (LOG). With the LO-Generator Control Board, the Divider Unit and the Buffer Board (both coming soon to your AJDI) they form the LOG Subrack. Two of the LOGs are connected to the APERTIF Down Converter Units (DCU), (see also here). These systems mix down the antenna signals to the baseband so that the Analog-to-Digital Converter Unit (ADU) can convert it eventually to a digital data stream.

Design and production of the PLL unit is another good example for the outstanding collaboration between our mechanical and electronic department here at the ASTRON labs. Keeping phase drift between the different units under control was a big challenge, but fruitful discussions between mechanical- and radio engineers have led to a well performing system at reasonable cost. The slideshow depicts some aspects of mechanical design, control soft- and hardware development and the qualification in the climate chamber.