High Frequency Radio Astronomy Laboratory

Current research in the High Frequency Radio Astronomy Laboratory in the Department of Astronomy at the University of Maryland, concentrates on developing wideband spectrometers for a variety of applications in radio astronomy.  Below, find some images of some of our equipment, some of the hardware we have developed and built, and a list of facilities and test equipment.

Views of the laboratory and some spectrometer components

lab view Laboratory testing of WASP2 and APHID spectrometer systems.
wasp2 boards The WASP2 circuit boards are four-layer hybrids of microwave and normal FR-4 circuit board material.  Most of the parts are surface-mount technology, allowing the boards to be assembled by pick-and-place robots.
prober station Suss PM5 probe station, oscilloscope, spectrum analyzer, synthesizer, 40 GHz network analyzer, and other equipment set up for testing a microwave integrated circuit
probing a chip Closeup of the probe station chuck with microwave and bias probes mounted on Quater micropositioners.
microwave module This integrated microwave module, shown with the cover open, is a dual 4-8 GHz downconverter with a biphase modulator before the top mixer and an LO power splitter and monitor point.  The box to the left is a commercial 8 GHz oscillator.
bonder Our West-Bond 7400B wirebonding machine welds 0.001" diameter aluminum and gold wires to integrated circuit chips.
bonded chip A microwave integrated circut, with size about 1 by 1 mm, with bond wires connecting it to a circuit board.
microcontroller boards An Intel 80C251SB microcontroller handles all real-time tasks for the WASP2 spectrometer.  The ADC clock signals are also generated on this board with a programmable logic chip.
WASP2 chassis A WASP2 spectrometer (bottom, 4U chassis) and power supply (top, 3U chassis).
Amplifier module
A dual-channel amplifier module for the WASP2 spectrometers.  From left to right, each strip contains a gain equalizer network, step attenuator, 4 GHz low-pass filter, amplifier, RF switch, and amplifier.  The small circuit board in the center contains the control electronics and a serial interface to the system computer.
agc board
A computer-controlled automatic gain control board for the COBRA digital correlator in the CASIMIR instrument for SOFIA.  The 500 to 1000 MHz microwave section has two amplifier stages, step and voltage-variable attenuators, switches for bypassing some of the attenuators, a gain equalizer network, and power detectors at the input and output.  A high-resolution image shows the board with the shielding cover over the microwave section.
aphid module The APHID correlator module and its control computer and electronics.  This correlator uses a single WASP2 circuit board for a 16-lag correlator with nearly 4 GHz bandwidth.  When combined with a 22 GHz receiver, the correlator measures the emission from a water vapor spectral line to find the amount of water over the antenna.  This information can be used to "detwinkle" the radio image measured by a millimeter wave interferometer.

Facilities and test equipment

Notes and other information

Questions or comments?  Please contact Andrew Harris.