A kinetic inductance detectors array design for high background conditions at 150 GHz

TL;DR

This paper proposes a 256-pixel kinetic inductance detector array with phased array antennas for high-background 150 GHz imaging, emphasizing low-loss materials and impedance matching for enhanced sensitivity.

Contribution

It introduces a novel array design integrating microstrip KIDs with phased array antennas optimized for high-background conditions at 150 GHz.

Findings

Achieves photon noise limited sensitivity with >100 pW optical power

Utilizes low-loss amorphous silicon dielectric for microstrip components

Implements NbTiN microstrip feed network for impedance matching

Abstract

We present a design for an array of kinetic inductance detectors (KIDs) integrated with phased array antennas for imaging at 150 GHz under high background conditions. The microstrip geometry KID detectors are projected to achieve photon noise limited sensitivity with larger than 100 pW absorbed optical power. Both the microstrip KIDs and the antenna feed network make use of a low-loss amorphous silicon dielectric. A new aspect of the antenna implementation is the use of a NbTiN microstrip feed network to facilitate impedance matching to the 50 Ohm antenna. The array has 256 pixels on a 6-inch wafer and each pixel has two polarizations with two Al KIDs. The KIDs are designed with a half wavelength microstrip transmission line with parallel plate capacitors at the two ends. The resonance frequency range is 400 to 800 MHz. The readout feedline is also implemented in microstrip and has an impedance transformer from 50 Ohm to 9 Ohm at its input and output.