Speaker
Mr
Shibo Shu
(The University of Tokyo)
Description
LiteBIRD is a next-generation satellite mission for measuring the primordial B-modes polarization signals of CMB. We describe a design of octave-band corrugated horn coupled planar ortho-mode transducer (OMT) with Microwave Kinetic Inductance Detector (MKID) as a candidate detection technology for LiteBIRD.
In our design, each single pixel contains 90 and 150 GHz two frequency bands, covering the maximum power part of CMB polarization signal. Through a 2.4 mm diameter circular waveguide, polarization signal are coupled to the 4-probe planar OMT structure silicon membrane, below which a backshort structure with quarter wavelength is fabricated by deep reaction-ion etching from the backside of silicon on insulator wafer.
After planar OMT, a broadband coplanar waveguide (CPW) 180-degree hybrid is used to cancel higher modes from circular waveguide. An Al/Ti center strip acts as absorber to absorb higher modes signal and TE11 signal is transmitted to a CPW-to-microstrip (MS) transition structure for connecting MS 5-element Chebyshev diplexer and following MKID. For coupling signal to MKID, the center strip of MKID acts as ground of MS and absorber to generate quasi-particle. For testing, a 4-pixel model is designed, containing 16 MKIDs and 4 dark MKIDs. MKIDs are designed with Nb ground plane and Al/Ti bilayer center strip line to achieve low frequency response and high sensitivity.
The 4-pixel broadband corrugated horn array is fabricated with high accuracy direct machining. Measurement shows that S11 parameter is lower than -10 dB from 80 GHz to 170 GHz and agree well with simulation. After calibration and testing, this prototype will be installed on Nobeyama 45-m telescope.
Primary author
Mr
Shibo Shu
(The University of Tokyo)
Co-authors
Dr
Agnes Dominjon
(National Astronomical Observatory of Japan)
Dr
Masato Naruse
(University of Saitama)
Mr
Shigeyuki Sekiguchi
(The University of Tokyo)
Prof.
Takashi Noguchi
(National Astronomical Observatory of Japan)
Dr
Tom Nitta
(Tsukuba University)
Prof.
Wenlei Shan
(National Astronomical of Japan)
Prof.
Yutaro Sekimoto
(National Astronomical Observatory of Japan)
