Antenna-coupled Superconducting Bolometers for Observations of the Cosmic Microwave Background Polarization

We describe the development of a novel millimeter-wave cryogenic detector. The device integrates a planar antenna, superconducting transmission line, bandpass filter, and bolometer onto a single silicon wafer. The bolometer uses a superconducting Transition-Edge Sensor (TES) thermistor, which provides substantial advantages over conventional semiconductor bolometers. The detector chip is fabricated using standard micro-fabrication techniques.This highly-integrated detector architecture is particularly well-suited for use in the development of polarization-sensitive cryogenic receivers with thousands of pixels. Such receivers are needed to meet the sensitivity requirements of next-generation cosmic microwave background polarization experiments.The design, fabrication, and testing of prototype array pixels are described. Preliminary considerations for a full array design are also discussed. A set of on-chip millimeter-wave test structures were developed to help understand the performance of our millimeter-wave microstrip circuits. These test structures produce a calibrated transmission measurement for an arbitrary two-port circuit using optical techniques, rather than a network analyzer. Some results of fabricated test structures are presented.