Alan Mast

Extending frequency and bandwidth through the use of agile, high dynamic range photonic converters

RF photonic techniques can be used to extend operating frequencies and bandwidth of mission communications and sensing systems. Photonic links inherently cover wide frequency bandwidths and optical modulators and detectors have been demonstrated that operate up to 100 GHz. This paper presents a photonic method for tunable high frequency carrier generation and wideband tunable RF frequency conversion. Photonic down-conversion measurements are presented with +24 dBm OIP3 and positive gain across RF input signals from 5 to 20 GHz. Additionally, measurements of undesired higher order mixing spurious products were more than 30 dB lower than those of typical RF mixers. Coupling wide-band optical components with a reconfigurable RF payload provides unprecedented agility and multi-mission utility for remote sensing, communications and SAR radar missions.

Reconfigurable Software Defined Payload architecture that reduces cost and risk for various missions

Harris has been delivering multi-processor based Software Defined Payloads (SDP) since 1998 resulting in a development path from RISC processor-based architectures to FPGA-based architectures. 12This paper presents implementations of Software Defined Radios (SDR) and payloads using this architecture. The modularity of this approach where size, weight, and power can be traded for increased performance is leading the way in responsive and flexible space payloads.

Electronic antenna calibration system and measurements for compensating real-time dynamic distortions

A real-time electronic aperture calibration system experiment was created to bring technologies and algorithms together in a pathfinder experiment to reduce the risk of electrically calibrating large dynamic apertures. These large, actively calibrated apertures have the potential to provide a significant increase in performance for many mission applications. A real-time calibration system was put into practice, demonstrated in an antenna range and the results of the dynamic antenna beam compensation experiments are presented. 12

Mixing spur reduction through photonic-assisted frequency conversion

Frequency converting systems can be severely limited by undesired spurious signals arising from combinations of odd and even harmonics of RF and LO inputs in an RF mixer. This work demonstrates the advantage of using photonic-assisted frequency conversion to reduce the impact of mixing spurs-both analytically and experimentally-showing truly 3rd-order limited performance and extending to millimeter wave frequencies.

Radios, payloads, & onboard processing made easy

The advent of reprogrammable software defined payloads has dramatically reduced the cost and complexity of developing space radios and remote sensing payloads. Over the last several years, Harris has been developing its AppSTARTM product line of reprogrammable software defined radios, including the NASA CoNNeCT SDR flying as part of NASAs SCaN testbed on the International Space Station. Since the CoNNeCT mission was launched in 2012, Harris has delivered over 100 software defined payloads (SDP), including those functioning as secondary hosted payloads for a variety of commercial and government applications. Looking to the future, investments were made in the second generation of Harris AppSTAR™ through radiation testing the latest commercial processors and packaging them together with radiation tolerant mitigation circuitry. Our new micro-SDR (μSDR) is packaged into a smaller volume, but yields significantly higher processing horsepower. The μSDR is capable of high rate communications capability over 1 Gbps, and its first launch is planned for mid-2017. The flexibility of the Harris AppSTAR™ architecture enables SDPs to be quickly developed to support communication and remote sensing mission needs. A variety of missions can be supported through application of SDP/radio technology which reduces the cost, risk, and schedule of achieving mission success.