DAVIS SITE FACILITIES

            At the main campus, the primary laboratory facilities include a far-infrared and millimeter wave magnetic fusion plasma diagnostics laboratory, a microwave/millimeter wave instrumentation and quasi-optics facility, high power microwave source and plasma interaction laboratory, and the synchrotron radiation light source laboratory comprising a total of 10,000 square feet. There is also a 10,000 square feet microfabrication facility. Furthermore, an additional 2000 square feet microwave laboratory opened in September 2000, when the new Engineering III building (across the street from EUII) was ready for occupancy. In the following, we have provided brief descriptions of each of these laboratories together with the major equipment capabilities, as well as the computational facilities, available to the group.

(a) Front view

(b) Rear View

New Engineering III, home of the Applied Science Department

Engineering Unit II Department of Electrical and Computer Engineering

The Microwave/Millimeter Wave Instrumentation and Quasi-optics Facility (Kemper Hall Room 3182)

            The microwave/millimeter wave instrumentation and quasi-optics facility is housed in ECE space in Kemper Hall (Room 3182) and is shared with Professor G. R. Branner. The facility possesses a number of state-of-the-art systems: HP8510B automated vector network analyzers, HP 8757 scalar network analyzers, HP sweepers, HP 8910B noise figure test set with 86671B synthesizer, HP spectrum analyzers, an HP 3048A phase noise system with 8662A synthesizer together with millimeter wave source and measurement capability up to 170 GHz. The primary DAS research in this facility has been directed toward monolithic, quasi-optical grid arrays for high power millimeter wave power generation and beam control and the use of novel nonlinear transmission lines for ultrashort pulse generation. Major advances have resulted in new concepts for automotive collision avoidance radar and phased array antennas for satellite communications. Together with radar based speech recognition systems.

Millimeter Wave Measurement Setup in Kemper Hall (Room 3182)

HP 8510C Network Analyzer

HP 3048A Phase Noise Measurement System


Computer controlled microwave anechoic chamber (a) test setup and (b) phased antenna array under test within chamber

The High-Power Microwave Source and Plasma Interaction Laboratory (Walker Hall 160)

            The high power microwave source and plasma interaction laboratory (160 Walker Hall) comprises 1800 square feet and possesses 0.5 MW ac service and features a chilled water recirculation system, thereby permitting high average power experiments. Several large (~1-2m) plasma chambers permit the careful investigation of the physics associated with laser fusion by scaling the laser wavelength to the microwave region and consequently the micron-millimeter sized targets to meter scale lengths. Microwave-plasma interactions are used to model laser-plasma interactions with applications to the inertial confinement fusion research program. Basic laboratory studies are also conducted on the use of reflectometry as a diagnostic for the determination of density profiles and fluctuations in magnetic fusion plasmas. Significant activity is being devoted to the development of high current density oxide cathodes. A new superconducting magnet solenoid is utilized for the development of high power 94 GHz harmonic gyrotron's and gyro-TWTs. A computer controlled TWT test station provides drive power from 40-100 GHz for the gyro-TWT developments as well as solid state quasi-optical frequency multiplier array studies. In addition to the above, the building also contains a well-equipped machine shop where experimental devices are fabricated in support of both Davis and Livermore based DAS programs.

 

High Power Amplifier Evaluator Test Equipment Cabinet and computer console.. The millimeter-wave component boards which provide and monitor the TWT input and output signals can be seen in the middle of the picture in the background. The ETM 5042PQU TWT Power Supply / Modulator control panel can be seen in the background to the left.



ETM 2513PG TWT Power Supply/ Modulator


Refrigerated 50 kG superconducting solenoid for millimeter-wave gyrotron tests

 

Vacuum chamber and electronic components for plasma deposition for the Oxide Cathode Project

 

Dedicated UHV surface analysis chamber

The Far-Infrared and Millimeter Wave Magnetic Fusion Plasma Diagnostics Laboratory (EUII 1209)

            The far-infrared and millimeter wave magnetic fusion plasma diagnostics laboratory (Room 1209, EII) was established to provide novel diagnostics instrumentation for next generation tokamak magnetic fusion plasma devices. Recent developments have ranged from a monolithic imaging millimeter wave receiver array for the determination of temperature fluctuations to an ultrashort pulse reflectometer system for the measurement of density profiles and density fluctuations. Unique instrumentation includes tunable carcinotron sources operating at frequencies as high as 420 GHz as well as novel optically pumped molecular lasers operating up to 3 THz.

Schematic of high power four-electrode CO2 laser developed for optical pumping FIR lasers

Photograph of CO2 laser system together with FIR lasers assembly. Three optically pumped far infrared (FIR) lasers are for the tangential interferometer-polarimeter system for NSTX.

            This laboratory is also home to both manual and automated probe stations for characterizing millimeter-wave circuits and grid arrays. Below is a photograph of two probe stations. The unit on the right is an automated system which is utilized to characterize thousands of devices contained on monolithic diode arrays and which has proved invaluable in the characterization of high speed switch arrays for moderate pulse reflectometry. On the left is a probe system outfitted with millimeter wave Cascade probes which permit measurements from a dedicated HP8510 B millimeter wave network analyzer and Tektronix 11802 50 GHz digital sampling oscilloscope.

 

Two probe stations utilized for characterization of millimeter-wave circuits and grid arrays

Microfabrication Facilities

            The  group carries out developments of many of the diagnostic components such as MEMS delay lines for electronic beam shaping for imaging reflectometry in the Northern California Nanotechnology Center which includes a 10,000 square feet, Class 100 microfabrication facility (see below). Housed within this facility is a plasma reactive ion etcher (Thermco Model 790 Plasma Processor) provided by UC Davis as cost sharing for the Investigator’s millimeter wave plasma diagnostics which supports deep ion etching of silicon micromachined devices. In addition, a new focused ion beam system obtained under a successful DURIP proposal (Prof. Ben Yoo, PI) supports the etching of Gas-As and InP devices. The diagnostics group also possesses a rapid thermal annealer and hot plate system for Ohmic contacts.

Photograph of Class 100 microfabrication facility

 

Computer Facilities

A dedicated computer facility and data-, tele- and video-conferencing center is set up in 228 Walker Hall, adjacent to the office space assigned to the Investigator's research staff. The group possesses considerable microwave circuit and structure design and simulation capability which plays a major role in the group's millimeter wave technology developments. All the dedicated super PCs and Sun workstations are outfitted with commercial software including 3-D, finite element EM codes (Ansoft's HFSS ), 2-D method of moments codes (Agilent's Momentum) and linear and nonlinear microwave circuit analysis modeling codes (Agilent's ADS). Other major commercial codes that are being used include the full wave 3-D method-of-moment EM code named IE3D from Zeland with which we design and simulate imaging antennas and wide bandwidth electronics,  RF/Microwave circuit simulator (Agilent’s ADS), 3-D FDTD EM simulator QuickWave-3D by QWED, imaging optics designs (reflective and transmissive) for MIR and ECEI systems by CODE-V, and Ansoft Designer for High-performance RF/mW Design & Analog/RFIC Verification. In addition, the group belongs to the Magic Users Group and has both the 2-D and 3-D versions of this PIC code. Finally, the group has access to a variety of supercomputers.

The figures below show the dedicated computing laboratory running the simulation software mentioned above and the data-, tele- and video-conferencing center.  Next are the Ansoft HFSS simulator running elliptical lens design, 3-element Elliptic Tapered Slot Antenna array design and Ka band standard Pyramidal Horn Antenna simulations. Microstripline to CPS balun is designed using Zeland IE3D. The current distribution is calculated by IE3D and shown here. A multiple-ring power divider is simulated by using Agilent ADS. Next is the optical design by using CODE-V. And the simulations tools for FSS notch filter designs by using Ansoft Designer and QuickWave-3D by QWED. The simulators' capabilities are further developed by the group.

 

Computing and Modeling Facilities

Data-, Tele- and Video-Conferencing Center

Using Ansoft HFSS EM Simulator for Elliptical Lens Design

 

                                                                                                                                                                                                          

                                                                                                                                                                                                      

3-element Elliptical Tapered Slot Antenna simulated by Ansoft HFSS
(a) Antenna structure; (b) 3-D far field pattern; (c) E-plane far field pattern; (d) H-plane far field pattern.

 

   

                                                                                                                                                                                                

(c)

Ka band Pyramidal Horn Antenna simulated by Ansoft HFSS
(a) Pyramidal Horn Antenna structure; (b) Field distribution at waveguide feeding port; (c) E-plane and H-plane radiation pattern.

(c)

(d)

Micostripline to CPS balun simulated by Zeland IE3D
(a) Back-to-back structure; (b) Current distribution at 10GHz; (c) Return loss; (d) Insertion loss.

 

Miltiple-Ring Wilkinson power divider simulated by Using Agilent ADS
 

Optical Design by Using CODE-V Simulator

FSS Notch Filter Design by Using Ansoft Designer Simulator

 

(a)

(b)

FSS Notch Filter Design by Using QWED QuickWave-3D
(a) Software Interface; (b) Simulation Results

 


(Last modified: Feb-07)