NASA Summary
Identification and Significance of Innovation:
Emerging digital radio receiver and data collection technology makes use of high-speed ADC (analog to digital converter) techniques to convert analog signals into digital signals that can be processed by DSP techniques. The flexibility and effectiveness of these digital techniques is determined by the number of bits of precision that can be supported by an ADC. VIDA will facilitate this new level of capability by changing the core technology of generating pure radio frequency (RF) signals, including the millimeter wave bands. The VIDA Differential Resonant Ring Oscillator (DRRO) has produced extremely low jitter digital clock signals at any frequency from 5 to 25 GHz by exploiting the high Q resonance of Yttrium Iron garnet material (YIG). Theoretical Q of a YIG resonator will increase with increasing frequency with the frequency determined by the magnetic field strength immersing the YIG. Innovation was required to generate an efficient magnetic field of sufficient strength to properly bias the YIG resonator above 20 GHz, to control the parasitic resonances in order to provide the effective Q necessary, contain the oscillator in a small package, and produce a path to make a Monolithic Microwave Integrated Circuit (MMIC) version.
Technical Objectives and Work Plan:
Produce a universal oscillator design that can be constructed and tested for a production prototype. Analyze and design the methods that will be used to stabilize the magnetic bias, to test engineering models to support a detailed design of the oscillator, and to confirm that the DRRO will perform to the required specifications. Identify and test supporting functions such as Direct Digital Synthesis devices, current drivers, regulators, circuit board layout, and microwave interfaces. Design and model a MMIC that will provide amplifiers for the DRRO with features that perfect the use in an oscillator topology.
Technical Accomplishments:
A prototype oscillator was designed and significant performance including phase noise, power versus frequency, and spurious signals were tested on engineering models. A method of using Hall effect gyrators to sample the magnetic field and provide data to correct the bias magnetic field was analyzed and a novel approach that should meet the objectives has been formulated. A novel approach to both generate a sufficiently strong magnetic bias field and provide an efficient control-tuning field has been created and modeled using FEI program. The Differential Resonant Ring Oscillator circuit model has been strengthened. Phenomenon inclusion such as the non-reciprocal oscillation range observation and phase noise behavior verses frequency has been addressed. Testing Phase noise and jitter has been addressed and methods to provide sufficiently refined data identified. A distributed amplifier that should be suitable for realizing a DRRO has been modeled and the result are good
NASA Application(s):
The Universal Oscillator will invaluable in communications and sensors such as ADC. It can be used for both fixed frequency clock oscillators and multi-octave tunable receivers and transmit exciters. This capability has never existed before and will make profound changes in systems design. When used to clock the latest ADC developments, direct digital radios operating above 15 GHz will be possible. Sensor accuracy will provide the tools for the next generation of earth atmospheric monitoring satellites to provide exact information to gain control of Global Warming. The versatility of the Universal Oscillator will provide redundancy for deep space application since several clocks can be reconfigured as necessary for the task at hand. High-speed computers will also more reliable when utilizing low jitter clocks. The recent advances in SiGe bipolar transistor frequency dividers can be used with GHz clocks to generate most of the lower frequencies improving phase noise by 6 dB per octave of division.
Non-NASA Commercial Application(s):
The Universal Oscillator MMIC will be extremely scalable in production and can be made in quantities and for cost equivalent to the current cell phones. The improved phase noise performance has potential to revolutionize WiMax of the future in that the number of users in a zone does not impact the data speed. The application of cognitive radios is waiting for the existence of hardware to permit reconfiguration of the radio links and the Universal Oscillator is able to supply that “missing piece” of the puzzle. Robotics needs sensors that are not jammed by neighboring signals from other nearby source, for example other robots. The low phase noise means that adjacent channels can be clean of interfering signals. This also has application in vehicular radar where the capability must not be reduced with wide spread implementation.
Name and Address of Principal Investigator:
Ronald Parrott, VIDA Products, Inc.; 3553 Westwind Blvd, Santa Rosa, CA, 95403-8256
Name and Address of Offeror:
VIDA Products, Inc.; 3553 Westwind Blvd, Santa Rosa, CA, 95403-8256