Specialized Arrays Inc. 700 Wavecrest Ave Unit 103, Indialantic, FL 32903

our rigorous simulation to prototype process saves time and money

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'Switch Points'  Click to enlarge

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coherent transmit and receive arraying demonstration

The element and array model alone is used to calculate the phase adjustments for transmission.

Right Image:  The model-based method along with a signal in the main beam of an antenna is used to mitigate atmospheric effects.  This is required at high frequencies such at Ka-band (32 GHz).   This concept was 1st demonstrated on NASA-funded TxACE program using 3-12m reflector antennas 60m apart at X-band (8GHz).  The technology was not demonstrated on the Orion program since it was conducted indoors (in a compact range).

In 2008 SAI founders, Martin and Minear demonstrated conformal body uplink arraying.

A full-scale mock-up of NASA's crew exploration vehicle, the Orion was constructed in a compact range.  It was fitted with two 4-element phased arrays.  The phased arrays were arrayed together on transmit and receive.

Read more (page 13 AIAA Conference paper)  

Additional details

Model-based System Calibration for Control Systems, describes the successful modeling of a conical (conformal body) platform containing patch antenna elements.  The inventors found experimentally that model parameters were "quickly obtained that provided good agreement between modeled and measured output."   This finding indicates the viability of widely-spaced, model-based conformal-body arraying.  

Primary benefits:  Nearly spherical coverage as opposed to traditional 'switched' methods that are position dependent and have power drops as a result of switching between antennas

Applicable to:   Spacecrafts such as NASA's ORION and SpaceX's Dragon;  Landers, such as China's Chang'e 3;  Launch vehicles such as SpaceX's Falcon 9; Aircraft; Ships; Satellites; Vehicles.

Antenna elements (or subarrays) can be placed on available space on a wide variety of platforms including launch vehicles, aircraft, ships, and ground vehicles.  These elements can then be arrayed (combined).  Built-in redundancy, better COMM coverage, and the ability to determine a signal's angle of arrival of some of the benefits of conformal body arrays.

Switch points:   The figure to the left displays a significant advantage of arraying widely-spaced elements.  The best coverage is provided between subarrays (switch points) where traditional 'switched' systems have the worst coverage.  For example, two apertures with equal gain at cross-over could be reduced in size by half using adaptive combining instead of switching between the two.

potential platforms for sai widely-spaced coherent Tx/Rx arraying technology

Our three-point integrated system design approach

1.  Creation and simulation of custom mission-specific array configurations
2.  On-board hardware design and algorithm development for real-time decision making including emitter characterization such as frequency, location, pulse rate, and bandwidth.  This can reduce data link burden.
3. Operations Center post-processing hardware and software so as to reduce power, weight, and size requirements at the array.  Post processing examples are AOA (angle-of-arrival) refinement and emitter geolocation.

Benefits of arraying widely-spaced elements (or subarrays) on platforms such as a spacecraft, rocket, humvee

  1. Switch points:  Best coverage between subarrays (switch points) where traditional switched systems fail  (image provided below)
  2.  Coverage:  Potential for nearly spherical coverage for COMM 
  3.  Power/Mass:  Reduced power and mass for a given data rate (G/T and EIRP) 
  4. Receive:   up to 3dB G/T increase each time the number of elements is doubled 
  5. Transmit:  up to 6dB EIRP increase each time the number of elements is doubled
  6. Open loop:  Adaptive models only are used to combine apertures for coherent transmit in cases where atmospheric effects are negligible
  7. Simultaneous links:  Multiple link support
  8. Inherent redundancy:  Handles element failures
  9. Anomaly mitigation:  Regain vehicle contact during anomalous situation via AOA of transmitted signal
  10. Element placement is flexible: can be placed in available space
superior Coverage   -   Multi-link Support   -   inherent redundancy

Patent:  Conformal-body uplink array is described in patent: 20100125347, "Model-based System Calibration for Control Systems."   Patent status:  Abandoned 

Orion Mock-up Prototype Comm System (2008)

widely-spaced Conformal Body transmit and receive arraying

Definition:  Adaptive combining of widely-spaced elements or groups of elements (subarrays) on the body of a static or moving structure for simultaneous coherent transmission and reception of signals