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Scalable RF Front End Technology

VISAT™ (Vertically Integrated Scalable Antenna Tile) is an innovative RF front end technology under development by EMAG Technologies Inc. for more than ten years. Its objective is to provide a generic, modem-agnostic, reconfigurable RF front end solution for data links, ground-based, aerial and satellite communications, radar and electronic warfare systems. Point-to-point data transmission and tracking require high-gain, narrow-beam antennas with versatile and agile beam steering capability. VISAT provides a compact, three-dimensional, vertically integrated architecture for active electronically scanned antenna (AESA) arrays that is based on low-cost commercial printed circuit board (PCB) manufacturing processes.

VISAT architectures are scalable over different frequency bands. EMAG has successfully demonstrated VISAT arrays at S, C, X, Ku and K bands. But the most important aspect of VISAT is aperture scalability. Think of VISAT tiles as LEGO building blocks for AESA. You can simply interconnect VISAT tiles to build very large radiating apertures. In addition to the use of commercial off-the-shelf (COTS) components and standard low-cost PCB processes, the highly scalable architecture helps reduce the non-recurring engineering (NRE) cost of VISAT systems by a large factor. Since VISAT tiles are digitally controlled, they makes it possible to realize software-defined reconfigurable and steerable apertures for low-power applications or time-limited, power-constrained missions.

Versatile RF Front End Solutions

VISAT technology supports a comprehensive integration concept accommodating thermal management, DC power conditioning and digital beam control using an onboard microcontroller with digital signal processing (DSP) functionality. A VISAT tile is a complete self-contained RF front end with DC, IF and LO connectors and digital (SPI) interface with the onboard microcontroller.  A single VISAT tile operates as a stand-alone active phased array with a rather broad beam and limited beam steering capability. VISAT tiles can easily be tiled together and create larger apertures with higher gains and narrower beams. VISAT arrays provide unmatched levels of SWaP (size, weight and power). For example, a single 16-element X-band AESA tile provides an effective isotropically radiated power (EIRP) of more than 17dBW within a total surface area of 60mm x 60mm.

Some of the key features of VISAT arrays are listed below:

  • VISAT provides true active electronically scanned antenna (AESA) operation. Each radiator represents a complete independent software-defined RF channel.
  • Multilayer stack architecture integrates antenna layers, amplification and frequency conversion stages (mixers, PAs, LNAs), digital phase shifters and digital attenuators, DC conversion, and onboard microcontroller/DSP.
  • 3D vertically integrated architecture accommodates T/R modules with half or full duplex operation as well as separate transmitter and receiver realizations.
  • Modem-agnostic architecture allows for shared aperture operation by several systems with different functions such as data communications and asset tracking.
  • VISAT designs are available for L, S, C, X, Ku, K and Ka bands (1 – 40 GHz).
  • It is possible to design dual-band VISAT arrays with a common aperture.
  • Different antenna designs can be adopted featuring linear vs. circular polarization, narrowband vs. wideband, etc.
  • VISAT designs accommodate GaAs, GaN, CMOS and other silicon-based components either in surface mount packages or in the form of bare die in a buried cavity with wire bonds.
  • Easy aperture scalability is made feasible using daisy chain connection or through direct feed distribution networks.
  • The local oscillator (LO) signal can be supplied externally or generated using an onboard phase locked loop (PLL) frequency synthesizer or transferred tile to tile via daisy chain.
  • VISAT arrays typically provide a field of view of ±55° with a scan loss better than (cosθ)1.5.
  • The thermal management of VISAT arrays can be customized to operate at operating temperatures above 50°C.
  • Graceful degradation – Unlike many other architectures, VISAT arrays degrade gracefully. All of the single point failure modes are either passive or can be made highly reliable.
  • Easily accessible test points on most layers allow for convenient and cost-effective serviceability.
  • VISAT arrays have been designed for automated manufacturing – a critical requirement for the fabrication of large active phased arrays.
  • VISAT technology offers low manufacturing cost as well as reduced NRE cost thanks to its generic scalable architecture.

Compact Multifunction Active Phased Arrays

Integrated RF front ends are the cornerstone of the next generation of wireless and satellite communications systems, intelligent sensors and electronic warfare machinery. The ability to transmit and receive vast amounts of information from ground, satellite, mobile, airborne or spaceborne platforms to large numbers of users requires revolutionary concepts in antenna design, circuit implementation and fabrication techniques to achieve what is considered by today’s standards the ultimate performance, smallest size and minimal cost.

The VISAT architecture allows several different types of functions to be integrated into a single aperture. A shared multifunction aperture provides numerous system integration opportunities such as combining a communications front end with a precision tracking system to address the beam pointing challenges of mobile point-to-point data links. A few examples of VISAT applications include:

  • Satellite communications on-the-move
  • Collision avoidance radar systems
  • Secure point-to-point communications systems
  • Tactical data links in networked battlefield environments
  • UAV airspace management
  • Cooperative asset tracking
  • Projectile guidance systems

Low-Cost High-Performance Integrated RF Systems

EMAG Technologies Inc. has developed a wide range of communications, radar and tracking solutions based on the VISAT technology. Our scalable RF front end solutions are modem-agnostic and can easily be integrated and interfaced with your software-defined IF or baseband back ends. It is as simple as a few connectors: DC, IF, LO and digital control lines. The VISAT technology can give you a significant competitive edge from a cost-performance standpoint. Due to the proprietary nature of the technologies involved, we encourage you to contact us and discuss your specific requirements for further exploration of possible opportunities under a non-disclosure agreement (NDA).

VISAT Tiles Demonstrated at Various Frequency Bands

EM.Cube model of dual S/C-band AESA tile (circular polarization)

EM.Cube model of X-band AESA tile

Examples of VISAT Platforms and Applications