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The Yuan-Tseh Lee Array for Microwave Background Anisotropy (AMiBA) is the first interferometer dedicated to studying the cosmic microwave background (CMB) radiation at 3mm wavelength. The choice of 3mm was made to minimize the contributions from foreground synchrotron radiation and Galactic dust emission. The initial configuration of seven 0.6m telescopes mounted on a 6-m hexapod platform was dedicated in October 2006 on Mauna Loa, Hawaii. Scientific operations began with the detection of a number of clusters of galaxies via the thermal Sunyaev-Zel'dovich effect. We compare our data with Subaru weak lensing data in order to study the structure of dark matter. We also compare our data with X-ray data in order to derive the Hubble constant., Comment: accepted for publication in ApJ (13 pages, 7 figures); a version with high resolution figures available at http://www.asiaa.sinica.edu.tw/~keiichi/upfiles/AMiBA7/pho_highreso.pdf

This is to report on our development for a dual-polarization receiver to detect the cosmic microwave background (CMB) in 85 to 105 GHz band. The receiver is based on a MMIC, HEMT-based LNA developed in the Jet Propulsion Laboratory. A W-band, orthomode transducer (OMT) is used for polarization separation. Most of the RF front-end is located in cryogenics environment at 20K. We have developed a MMIC sub-harmonically pumped diode mixer, operating at 42 GHz, for signal down-conversion. The entire base-band, 2 to 18 GHz, is correlated in a lag-correlator system. The receiver design details and the lab test results will be described in this report.

This is to report on our development for a full-polarization receiver to detect comic microwave background in 85 to 105 GHz band. Two such receivers have been built and tested, and currently undergoing site-testing on Mauna Loa, Hawaii. Each receiver is a very sensitive coherent detector to operate in 85-105 GHz with full polarization capability. Most of the receiver front-end components, including feed-horn, ortho-mode transducer, and low-noise amplifiers, are located in a cryogenic environment. We have designed a MMIC sub-harmonic pumped mixer, operating at 42 GHz, for signal down-conversion. In order to detect faint polarization signals in microwave background, a wide base-band, 2 to 18 GHz, is specified in the receiver design, and the entire base-band will be correlated. The receiver design details and the lab test results will be described in this report.