A Compact Filter-Bank Waveguide Spectrometer for Millimeter Wavelengths
  We present the design and measurements of a 90GHz prototype of a
millimeter-wave channelizing spectrometer realized in rectangular waveguide for
astronomical instrumentation. The device was fabricated using conventional
high-precision metal machining, and the spectrometer can be tiled into a 2D
array to fill the focal plane of a telescope. Measurements of the fabricated
five-channel device matched well with electromagnetic simulations using HFSS
and a cascaded S-matrix approach. This motivated the design of a 54-channel
R=200 spectrometer that fills the single-moded passband of rectangular
waveguide in the 130-175 GHz and 190-250 GHz atmospheric windows for
millimeter-wave spectroscopic mapping and multi-object spectroscopy.
