A High-Sensitivity Fourier Transform Spectrometer for Cosmic Microwave Background Observations

Abstract

The QUIJOTE Experiment was developed to study the polarization in the Cosmic Microwave Background (CMB) over the frequency range of 10-50 GHz. Its first instrument, the Multi Frequency Instrument (MFI), measures in the range 10-20 GHz which coincides with one of the naturally transparent windows in the atmosphere. The Tenerife Microwave Spectrometer (TMS) has been designed to investigate the spectrum between 10-20 GHz in more detail. The MFI bands are 2 GHz wide whereas the TMS bands will be 250 MHz wide covering the complete 10-20 GHz range with one receiver chain and Fourier spectral filter bank. It is expected that the relative calibration between frequency bands will be better known than the MFI channels and that the higher resolution will provide essential information on narrow band interference and features such as ozone. The TMS will study the atmospheric spectra as well as provide key information on the viability of ground-based absolute spectral measurements. Here the novel Fourier transform spectrometer design is described showing its suitability to wide band measurement and √ N advantage over the usual scanning techniques.

A metamaterial with applications in broad band antennas used in radio astronomy and satellite communications

“…several areas to explore the full potential of the meta-horn, such as shaping the horn with a smart curve profile instead of a conical profile (e.g., Gaussian [15]) or adding length to the antenna (thus increasing the number of meta-rings) in combination with a further computer aided optimization. This would make it possible to simultaneously cover both the K 𝑎 and K 𝑢 bands with a single receiver for satellite communications, or to cover broader bands reducing the complexity and enhancing the sensitivity of telescopes for radio astronomy [19,20].…”

A metamaterial with applications in broad band antennas used in radio astronomy and satellite communications

“…Different areas to explore the full potential of the meta-horn are: shaping the horn with a smart curve profile instead of a conical profile (e.g., Gaussian [16]), adding length to the antenna (thus increasing the number of meta-rings) in combination with a further computer aided optimization. This could render the goal of simultaneously covering both the K a and K u bands with a single receiver for satellite communications closer, or to cover broader bands reducing the complexity and enhancing the sensitivity of telescopes for radio astronomy ( [17], [18]).…”

A dark matter telescope probing the 6 to 60 GHz band

“…This would facilitate the directional observation of relativistic axions, where the line width of the axion 19 (or DP) may be considerably wide, approaching ∆ν a /ν 0.5 in some cases. This scheme (e.g., see [110]) is not shown in the figure for simplicity.…”

“…Hence, the mitigation of low frequency gain fluctuations caused by thermal and 1/f noise contributions is significant. Receivers could be pointed to cold-loads as a reference calibration signal, if necessary (e.g., see [77] and references therein). This might render the directional observation of relativistic axions possible, even in specific cases where the line width of the axion 17 (or DP) may be considerably wide, approaching ∆ν a /ν ∼ 1 in extreme cases.…”