Antennas

Since 2010, MDA has delivered more than 30 reflectors and multiple reflector pallets. Reflectors are available in sizes up to single 2.6-metre diameter, or on pallets holding up to five reflectors, each option designed for the most severe dynamic and acoustic environments using three or four hold-down points. Thermal ranges supported span -170ºC to +145ºC.

MDA deployable reflectors deliver high as-built surface accuracy even with severe shaping, with optimization for low surface thermal distortion and pointing errors. High-performance sunshields and thermal protection, together with MDA’s space-qualified hold-down and release mechanisms, ensure rugged, dependable deployment and operation.

MDA delivers complete turnkey Ka-Band antenna solutions for multibeam missions. The design incorporates a patented ultra-high efficiency, smooth-wall feed horn technology that enables exceptional edge-of-coverage (EOC) gain, and sidelobe isolation performance. The flexible design enables delivery of complete antenna subsystems with RF tracking and reflectors, or standalone feed clusters.

MDA multibeam antennas are available in C-, Ku-, Ka- and V-Bands, and all feature highly directive feeds, using uniform and non-uniform beam sizes. Diplexed Tx/Rx dual circularly polarized feed chains provide optimal illumination to yield beam congruency with uncompromised Tx and Rx gain and C/I performance.

The design combines RF-tracking, user, and gateway links in a single feed chain to support wideband users over 
1.5 GHz, and gateway feeds. Feed clusters deliver very high thermo-elastic stability, while multiple reflector pallets ensure high surface accuracy. MDA’s design-for-manufacturing approach lowers the cost of integration and test, and high-density packaging can provide 220 feeds per satellite. Several colour schemes are available.

MDA developed the deployable RADARSAT Synthetic Aperture Radar (SAR) antenna to collect the most advanced commercial C-Band radar imagery in the world. The RADARSAT antenna is an active phased array, with C-Band Transmit​/Receive modules, two-dimensional electronic beam forming, and dual- and quad-polarization imaging capabilities. It transmits circular polarization with dual receive, independently defining the beam for each pulse, to image a swath of up to 500 kilometres wide.

MDA has also designed, built, and delivered advanced communication antennas for the International Space Station and European Mars Mission (ExoMars) in the
S-, X- and Ku-Bands.

MDA altimeter reflectors are at the forefront of design and capability for high-accuracy space borne altimetry missions, to provide compact implementations for C- and Ku-Band feeds, with very low sidelobe and ultra-stable group delay.

MDA is at the leading edge of design and build technology for MSS feed array subsystems, including transmission lines, filters, diplexers, output networks, radiating elements, mutual coupling control features, embedded heat pipes, and thermal hardware.

MDA’s high power handling designs incorporate high-efficiency helices and a patented high power, high stability filter design. The arrays are dielectric-free, and PIM free at the 5^th order. MDA’s flexible design enables up to 120 radiating elements per array, delivering a large bandwidth of up to 50 MHz in receive mode.

Large, high-power, high-efficiency UHF antennas are an important part of MDA’s catalogue of antenna products for space, with proven success on international satellite communication programs. MDA provides two types of UHF helical antennas, a side-mounted deployable solid helix design typically configured as separated Tx and Rx antennas, and a top floor-mounted extendible helix design configured as combined Tx/Rx antennas. Both antennas provide high gain performance in CP for global Earth coverage, with an EOC Gain greater than 14dBi and a typical operating frequency of 240 to 320 MHz.

Both antenna designs are large, very lightweight deployable structures for PIM-and-multipactor-free high-power, providing outstanding performance over extreme temperature ranges. They are either rigid and supported by deployable booms, or collapsible into a very compact package suitable for accommodation in tight configurations. The design has high proven reliability and makes extremely efficient use of the mechanical envelope.

MDA’s Multi-Layer Insulation (MLI) and RF transparent Single Layer Insulation (SLI) thermal blankets address a broad scope of performance requirements. Included in the range of MLIs are sunshields, PIM-free solutions, rigid and soft radomes, ESD-friendly versions for low-to-medium surface resistivity, atomic oxygen resistant options, and varieties for deployable structures.

In addition to thermal blankets incorporated into most MDA antenna products, MDA manufactures custom blankets for several satellite programs and as standalone products for customers.

Due to ever-changing requirements that characterize each satellite program requiring MLIs, MDA has developed an innovative toolbox construction approach. It consists of standard MLI lay-ups that are space qualified for most applications, and use standard MDA-quality materials to minimize costs, fabrication time, and inventory.

MDA has developed a family of Direction Finding antennas to address modern military requirements, built entirely from International Traffic in Arms Regulations (ITAR)-free components.

MDA’s Spinning Antenna System (SAS) segment provides a 360-degree field of view (FoV) with high-gain, high-resolution directional antennas mounted on a precision turntable remotely controlled by an Antenna Control Unit (ACU) to support spin rates from 0 to 200 RPM. The ACU interfaces with Command and Control systems via an XML-compatible Ethernet interface to enable multiple operational modes, including Spin, Sector Scan and Designate, in addition to feeding operational status information back. Real time antenna resolver information is available via a 12-bit parallel interface.

The basic system operates in the 0.5-18.0 GHz bandwidth and comprises a Low Band 0.5-2.0 GHz Log-Periodic Dipole Antenna (LPDA) array. A High Band 2.0-18.0 GHz shaped antenna reflector with an LPDA antenna feed is also available in an optional extended 2.0-40.0 GHz variant. MDA’s radome-mounted SAS antennas are pre-configured for 45-degree slant linear polarization. The optional high Probability of Intercept (PoI) 45-degree slant linear polarized omni-directional antennas, covering the 0.5 -18.0 GHz and 18.0-40.0 GHz RF millimeter wave bandwidth, each with protective radomes, can be stacked on top of the SAS segment.

Designed to low-maintenance MIL-STD-810 and DO-160 standards, MDA’s ELINT/SIGINT components have been proven in the most demanding military environments.

Having delivered more than 50 side-deployable antenna systems in a decade​, MDA can deliver a range of antenna optics to comply with the most stringent requirements. The most common designs include Single Offset, Gregorian and Dual Gridded Reflectors, and all offer the choice of fixed or steerable main reflectors, single or multiple feeds, parabolic, super-elliptical or shaped reflectors, and converging or diverging ray shaping.

MDA has developed a strong expertise in high performance feed-chains with full mechanical/thermal design, RF and PIM testing. Its product line is third-order PIM-free, and delivers high CW and peak power. Designs include triplexers and quadplexers for wideband data feeds and combined frequency bands.

Over the past decade, MDA has delivered more than 20 complete C-band to Ka-band nadir antenna subsystems mounted on the earth deck of various spacecraft bus interfaces. MDA delivers its turnkey solutions fully tested and ready for AI&T at spacecraft level with waveguides or coaxial cable interfaces at the bottom of the antenna.

MDA can deliver a range of antenna optics to comply with the most stringent requirements. The most common designs include Single Offset, Gregorian and Dual Gridded Reflectors, and all offer the choice of fixed or steerable main reflectors, single or multiple feeds, parabolic, super-elliptical or shaped reflectors, and converging or diverging ray shaping.

MDA has developed flexible tower structure designs to enable standalone antenna configurations, or multiple combined installations on very complex antenna modules.

These solutions offer circular bus or square interfaces capable of supporting deployable main reflectors up to 2 metres diameter, with antennas stowed in their nominal pointing position (from GEO). Options include main reflector steerable only, or fully steerable to cover the complete Earth. The antenna structure integrates an embedded LNA box, and the tower accommodates AOCS devices and TM/TC antennas.

Underscoring MDA’s production capability, it has designed and manufactured more than 200 antennas for the O3b Network and Iridium Next small satellite constellations.

These antenna designs feature maximum gain at maximum scan angle, typically 60 degrees from Nadir using a proven tuneless Tx/Rx Ka-band feed chain. With a low-cost gimbal mechanism and high production rate, MDA inter-satellite link and feeder antennas are also well suited for applications such as Earth observation data downlink subsystems.

MDA L-band navigation antennas operate at L1, L2, L5, and E5 frequencies, and are compatible with EGNOS and WAAS systems. All MDA L-band antennas consist of direct radiating helix arrays, fed by a beam-forming network.

The antennas provide an excellent axial ratio of less than 1 dB, have an EOC gain greater than 16 dBi, and deliver excellent phase centre stability.

Based on the same technology, MDA has developed an expertise in L-band antennas with global or regional coverage that provide high power handling, PIM-free operation with combined or separate Tx and Rx.