In general, Micropower Impulse Radar (MIR) depends on Ultra-Wideband (UWB) transmission systems. UWB technology can supply innovative new systems and products that have an obvious value for radar and communications uses. Important applications include bridge-deck inspection systems, ground penetrating radar, mine detection, and precise distance resolution for such things as liquid level measurement. Most of these UWB inspection and measurement methods have some unique qualities, which need to be pursued. Therefore, in considering changes to Part 15 the FCC needs to take into account the unique features of UWB technology. MIR is applicable to two general types of UWB systems: radar systems and communications systems. Currently LLNL and its licensees are focusing on radar or radar type systems. LLNL is evaluating MIR for specialized communication systems. MIR is a relatively low power technology. Therefore, MIR systems seem to have a low potential for causing harmful interference to other users of the spectrum since the transmitted signal is spread over a wide bandwidth, which results in a relatively low spectral power density.

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Response to FCC 98-208 notice of inquiry in the matter of revision of part 15 of the commission's rules regarding ultra-wideband transmission systems

Advances in modern technology have aided the development of a class of miniaturized satellites called SmallSats that typically weigh less than 500 kg. Key members of this family are CubeSats. CubeSats can weigh as little as 1.33 kg, with a typical volume of 10 ? 10 ? 10 cm3. Their potential has motivated the scientific community to revisit existing spacecraft technologies to make them suitable for CubeSats.

For Satellites, Think Small, Dream Big: A review of recent antenna developments for CubeSats.

CubeSats are positioned to play a key role in Earth Science, wherein multiple copies of the same RADAR instrument are launched in desirable formations, allowing for the measurement of atmospheric processes over a short evolutionary timescale. To achieve this goal, such CubeSats require a high-gain antenna (HGA) that fits in a highly constrained volume. This paper presents a novel mesh deployable Ka-band antenna design that folds in a 1.5 U $(10\times 10 \times 15 \,\text{cm}^{3})$ stowage volume suitable for 6 U $(10\times 20 \times 30 \,\text{cm}^{3})$ class CubeSats. Considering all aspects of the deployable mesh reflector antenna including the feed, detailed simulations and measurements show that 42.6-dBi gain and 52% aperture efficiency is achievable at 35.75 GHz. The mechanical deployment mechanism and associated challenges are also described, as they are critical components of a deployable CubeSat antenna. Both solid and mesh prototype antennas have been developed and measurement results show excellent agreement with simulations.

CubeSat Deployable Ka-Band Mesh Reflector Antenna Development for Earth Science Missions

This article describes the development of a deployable high-gain antenna (HGA) for the proposed Mars Cube One (MarCO) CubeSat mission to Mars. The antenna is a new folded-panel reflectarray (FPR) designed to fit on a 6U (10 ? 20 ? 34 cm3) CubeSat bus and support 8.425-GHz Mars-to-Earth telecommunications. The FPR provides a gain of 29.2 dBic with right-hand circular polarization (RHCP). Small stowage volume is a key advantage of the FPR design, as it only consumes ~4% of the usable spacecraft payload volume with a mass of less than 1 kg.

A Deployable High-Gain Antenna Bound for Mars: Developing a new folded-panel reflectarray for the first CubeSat mission to Mars.

Antenna is one of the key components onboard small satellites as its design determines the performance of all the wireless systems including telemetry, tracking and control, high-speed data downlink, navigation, intersatellite communications, intrasatellite communications, wireless power transfer, radars and sensors, etc. This paper presents a review of recent development in advanced antennas for small satellites (MiniSat, MicroSat, NanoSat, CubeSat, etc.). A number of recent examples of antennas for small satellite applications are shown and discussed. A conclusion and future development in antennas for small satellites are given in the end.

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Advanced Antennas for Small Satellites

Two novel high gain deployable reflectarray antennas to support CubeSat telecommunications are described and compared with other high gain CubeSat antenna technologies. The first reflectarray is the Integrated Solar Array and Reflectarray Antenna (ISARA), a K/Ka-band antenna that also incorporates a dense packing of solar cells used to provide electrical power for the spacecraft. The second is an X-band reflectarray designed to provide a bent pipe telecom link. These reflectarrays are ideal for CubeSat applications because they require negligible stowed volume and impose a modest mass increase. The antenna designs and measured performance results are presented.

Novel deployable reflectarray antennas for CubeSat communications

Small satellites (smallsats) provide low-cost access to space and have historically been used for flight technology demonstrations and limited-function space science activities. Novel antenna technologies have enabled high-performance smallsat telecommunications, science in Earth orbit, and the first CubeSat mission to deep space. In the past five years, technologists at NASA's Jet Propulsion Laboratory (JPL) have designed, tested, and successfully flown these innovative and enabling smallsat antennas. This article describes these innovations and their impact on smallsat performance for recent and future NASA missions.

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Advanced CubeSat Antennas for Deep Space and Earth Science Missions: A review

The Integrated Solar Array and Reflectarray Antenna (ISARA) is a new deployable antenna designed to fit into a standard CubeSat bus. It does not occupy payload volume, provides spacecraft prime power and imposes only a modest impact on overall mass. Measured data indicates that the 3 panel configuration achieves 33.5 dB gain at 26 GHz. Measured radiation patterns are in good agreement with calculations.

ISARA - Integrated Solar Array and Reflectarray CubeSat deployable Ka-band antenna

An 18 to 110 GHz two-arm Archimedean spiral antenna directly fed with a Dyson balun is designed, fabricated, and measured. The feed line includes a monolithically integrated rectangular coaxial line impedance transformer designed to reduce the nominal antenna impedance from ~180 to 80 Ω and to match that impedance to the nominal system's impedance of 50 Ω. Full-wave modelling and impedance measurements are used to assess antenna performance. A VSWR <;; 2.5:1 is obtained throughout the measured band.

Directly fed millimetre-wave two-arm spiral antenna

An antenna formed by the union of a four-armed, reflective-backed spiral antenna with a top-fed quadrifilar helix, operating over the 0.35-2.6-GHz band, is presented. The antenna features a novel dual-layering scheme that allows the modal impedance of the four-armed spiral to be greatly reduced while maintaining the desirable self-complementary metallization. A reconfigurable end-loading scheme is also presented that allows the attachment of high power-handling resistive loads, which along with other design features enables the use of the antenna in high-power transmitting applications. Mode 1 VSWR less than 2.2 is maintained throughout the 0.35-2.6-GHz band. Respective cutoff and nominal gains of 0 and 7 dBiC with excellent pattern characteristics are demonstrated. Over 30 dB broadside cross-polarization discrimination and high conical pattern uniformity are also obtained.

Matthew J. Radway

Papers

Novel deployable reflectarray antennas for CubeSat communications

Advanced CubeSat Antennas for Deep Space and Earth Science Missions: A review

ISARA - Integrated Solar Array and Reflectarray CubeSat deployable Ka-band antenna

Directly fed millimetre-wave two-arm spiral antenna

Four-Armed Spiral-Helix Antenna