Department of Physics & Astronomy

Radio and Space Plasma Physics Group - Technical Reports

Technical Reports and documentation

• PC104 Synthesiser (October 2007) A DDS frequency synthesiser card capable of producing sine waves up to 80MHz. The unit is based around Analog Device’s AD9854 part. The card uses the PC104 computer bus, which is electrically similar to the standard ISA computer bus. Multiple cards can be stacked together and clocked from a common signal reference to provide multiple phase coherent signal sources. This card has been used extensively in the latest generation of CUTLASS style radars.
• Stereo Synthesiser Unit (October 2007) A source of multiple RF signals for the latest generation of Stereo CUTLASS radars. This 6U high unit contains six PC104 synthesisers and a small PC104 based computer to control the synthesisers. The computer runs the QNX4 operating system and becomes an additional node to the existing two nodes found on a conventional CUTLASS radar. All RF signal outputs are phase coherent to the common 50MHz input clock, which is provided by a rubidium frequency standard unit. Frequency synthesis of the transmitter exciter signals produces a spectrally purer signal than previous approaches that relied on mixing down the receiver local oscillator signals.