About Us

Stephens Labs, LLC, is an Arizona Limited Liability Company in good standing and organized under ARS§29-632.

We work with digital/RF/software specialists to provide turn-key solutions for your most challenging technical problems.

Scott Stephens has 25 years experience in sensor fusion (primarily for location estimation), communication systems engineering, and physics.

As sensor fusion engineer, created location systems for: 
  • robotic vehicles used for military scout activities, prototype sports stadium and commercial mowing, and agriculture, using GPS, inertial (accel, gyro, 'gyro-compass'), odometry, radar (including a novel ultra-wide-band radar design using passive and active transponders), magnetometer, and lidar (1D scanning and 3D total station tracking); 
  • asset and indoor location tracking using passive RFID (sequential ranging and array phase); 
  • satellite phone location (using CDMA ranging and phase from MEO and LEO satellite constellations); 
  • satellite location (TDRSS tracking of satellites via integrated doppler); 
  • geodynamic crustal-deformation studies (cross-correlation of quasar RF signals across thousands of miles for first long-baseline geolocation, followed by GPS network solutions).

As communication systems engineer: 
  • designed the acquisition and tracking algorithms for NASA/JPL's current deep-space network receiver (receiving info from all spacecraft beyond the moon), and lead implementation team; 
  • for commercial satellite programs Teledesic ("internet in the sky", Motorola), Odyssey (similar to Iridium, TRW), and Primosphere (similar to Sirius/XM, TRW), designed algorithms and lead implementation on techniques including: CDMA acquisition, tracking, and global time synchronization, satellite power control and phased-array optimization, RF propagation/fade modeling, and end-to-end link layer architecture trades and waveform design; 
  • for JPL's TurboRogue GPS receiver, designed acquisition and tracking algorithms, which were so flexible I used it to search for lost spacecraft (Landsat IV, Mars Observer) and to understand the Galileo-Earth orbit anomaly by tracking via TDRSS relay; 
  • optical comm link atmospheric wavefront distortion mitigation (TRW); 
  • advanced antenna design for terrestrial 77GHz comm and channel coding scheme evaluation (Motorola Labs); 
  • indoor RF signal propagation modeling for RFID (Mojix).

As physicist:
  • built a 500GHz receiver for use in radio astronomy, including fabrication of tunnel-junction detector; 
  • mapped molecular lines from galaxies; 
  • developed surface physics models for gas sensing.

Has 24 US patents (does not include corresponding European patents) for phase-locked loops, geolocation, CDMA synchronization, satellite power control for resource management, and mobile-satellite fade mitigation architectures, multi-beam planar antennas, RF local positioning systems, RFID realtime location, and surface physics gas sensors.

Degrees from Caltech (BS in Applied Physics; BS in Astronomy), University of Illinois (MS in Astronomy; studies emphasized electrodynamics, thermal physics, and quantum mechanics), USC (MS in Communication Systems and Digital Signal Processing)

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