Jennifer Edwards

High-Efficiency Elliptical Slot Antennas With Quartz Superstrates for Silicon RFICs

To increase the efficiency of on-chip patch and slot antennas, a single-layer superstrate is proposed. An analytical model to calculate the radiation efficiency is presented, and a detailed design approach is described. This antenna was implemented at W-band in the IBM CMOS8RF (0.13

A dual-polarized broadband planar antenna and channelizing filter bank for millimeter wavelengths

\mu {\rm m}

Dual-Polarized Sinuous Antennas on Extended Hemispherical Silicon Lenses

) process. The measured antenna results in a 3.9% impedance bandwidth, an efficiency of 30%, and a gain of 0.7 dBi at 89 GHz, which agrees well with simulations. The gain improvement with a quarter-wave superstrate is experimentally demonstrated to be 6.4 dB, representing a substantial improvement over traditional on-chip patch and slot antennas.

High-efficiency silicon RFIC millimeter-wave elliptical slot-antenna with a quartz lens

We describe the design, fabrication, and testing of a broadband log-periodic antenna coupled to multiple cryogenic bolometers. This detector architecture, optimized here for astrophysical observations, simultaneously receives two linear polarizations with two octaves of bandwidth at millimeter wavelengths. The broad bandwidth signal received by the antenna is divided into sub-bands with integrated in-line frequency-selective filters. We demonstrate two such filter banks: a diplexer with two sub-bands and a log-periodic channelizer with seven contiguous sub-bands. These detectors have receiver efficiencies of 20-40% and percent level polarization isolation. Superconducting transition-edge sensor bolometers detect the power in each sub-band and polarization. We demonstrate circularly symmetric beam patterns, high polarization isolation, accurately positioned bands, and high optical efficiency. The pixel design is applicable to astronomical observations of intensity and polarization at millimeter through sub-millimeter wavelengths. As compared with an imaging array of pixels measuring only one band, simultaneous measurements of multiple bands in each pixel has the potential to result in a higher signal-to-noise measurement while also providing spectral information. This development facilitates compact systems with high mapping speeds for observations that require information in multiple frequency bands.

Multichroic dual-polarization bolometric detectors for studies of the cosmic microwave background

This paper examines the performance of dual-linear sinuous antennas on silicon extended hemispherical silicon dielectric lenses. A theoretical impedance of 106 Ω is identified based on the analysis of an ideal self-complementary structure, and this result compares well with simulations and measurements. The radiation properties of a linearly polarized sinuous antenna are simulated using Method of Moments software coupled to a GO/PO code, and also agree well with measurements. The results indicate that the sinuous antenna is an excellent wideband planar feed for a silicon lens, with cross-polarization levels below -17 dB, and polarization variations of ±5° over two octaves in frequency. The application areas are millimeter-wave, wideband, dual-polarized radio-astronomy receivers.

A Log-Periodic Channelizer for Multichroic Antenna-Coupled TES-Bolometers

This paper presents a W-band on-chip elliptical slot antenna fabricated in the IBM CMOS8RF (0.13 µm) process. This antenna has a measured efficiency of 7% and a measured gain of −5.7 dB at 88 – 90 GHz. The measured impedance bandwidth is 3.1%. Although it is not efficient as a standalone element for RFIC applications, the elliptical slot is very promising as a feed for an extended hemispherical lens. Simulated results indicate that the antenna efficiency improves to 30% at 90 GHz using a quartz dielectric lens, with an impedance bandwidth of 4.4%. The simulated gain at 90 GHz is 15 dB when placed on 12 mm diameter lens, ideal for high gain silicon RFIC applications.

A dual-polarized multichroic antenna-coupled TES bolometer for terrestrial CMB Polarimetry

We are developing multi-chroic antenna-coupled TES detectors for CMB polarimetry. Multi-chroic detectors in- crease the mapping speed per focal plane area and provide greater discrimination of polarized galactic foregrounds with no increase in weight or cryogenic cost. In each pixel, a silicon lens-coupled dual polarized sinuous antenna collects light over a two-octave frequency band. The antenna couples the broadband millimeter wave signal into microstrip transmission lines, and on-chip filter banks split the broadband signal into several frequency bands. Separate TES bolometers detect the power in each frequency band and linear polarization. We will describe the design and performance of these devices and present optical data taken with prototype pixels. Our measurements show beams with percent level ellipticity, percent level cross-polarization leakage, and partitioned bands using banks of 2, 3, and 7 filters. We will also describe the development of broadband anti-reflection coatings for the high dielectric constant lens. The broadband anti-reflection coating has approximately 100% bandwidth and no detectable loss at cryogenic temperature. Finally, we will describe an upgrade for the Polarbear CMB experiment and installation for the LiteBIRD CMB satellite experiment both of which have focal planes with kilo-pixel of these detectors to achieve unprecedented mapping speed.

Sinuous‐Antenna coupled TES bolometers for Cosmic Microwave Background Polarimetry

We have fabricated a dual-polarized multichroic antenna-coupled bolometer prototype pixel for use in focal planes of Cosmic Microwave Background (CMB) polarimetry experiments and for submillimeter observations of high redshift galaxies. We couple millimeter and submillimeter power onto the detector with a dual polarized sinuous antenna that has a continuous bandwidth of 60-250 GHz and we use a contacting extended hemispherical lens to boost the gain high enough to match the optics of a typical telescope. We partition each polarization channel into seen contiguous channels with a channelizer circuit that mimics the physiology of the human ear and then terminate each channel on a separate TES bolometer. Fourier Transform Spectroscopy demonstrates that the bands are near the designed locations with total receiver throughputs of 20-30%.

Sinuous antennas for cosmic microwave background polarimetry

We are developing dual-polarized multi-channel antenna-coupled Transition Edge Sensor (TES) Bolometers for Cosmic Microwave Background (CMB) Polarimetry in terrestrial experiments. Each pixel of the array couples incident power into the lithographed microstrip circuits with a dual-polarized broadband planar sinuous antenna whos gain is increased with a contacting extended hemispherical lens. Microstrip filter manifolds partition the two-octave bandwidth into narrow channels before terminating at separate TES bolometers. We describe the design methodology and fabrication methods used, and also the results of optical tests that show high optical throughput in properly located bands, as well as high cross-polarization rejection. We have explored two antenna feeding schemes that result in different quality beams and we comment on the relative merits of each. Finally, we quantify the increases in mapping speed that an array of our multichroic pixels might realize over traditional monochromatic pixels.

High-efficiency elliptical-slot silicon RFIC antenna with quartz superstrate

We are developing antenna‐coupled TES bolometers for CMB polarimetry that receive both linear polarizations over nearly two octaves of bandwidth. This ultra‐wide bandwidth is achieved with a novel adaptation of the sinuous antenna that integrates microstrip feed‐lines onto the arms of the antenna and uses a contacting extended hemispherical lens to focus the beam. It is challenging to achieve desirable antenna performance over such a wide band and our version of the sinuous antenna offers a unique solution. We have integrated this antenna with TES‐bolometers and report on a series of optical tests that demonstrate the antenna beams’s high symmetry, cross‐polarization rejection, gain, and optical efficiency over the operating band.