CIRCE: Coordinated Ionospheric Reconstruction Cubesat Experiment

The Coordinated Ionospheric Reconstruction Cubesat Experiment (CIRCE) is a collaborative space mission between the UK Defence Science and Technology Laboratory (Dstl), and the US Naval Research Laboratory (NRL) in developing small satellite ionospheric physics capability. CIRCE will characterise space weather effects on a regional scale in the ionosphere/thermosphere system. Properly characterising the dynamic ionosphere is important for a wide range of both civil and defence applications such as GPS, communications, and sensing technology. Consisting of two near-identical 6U (2x3U) CubeSat buses, the CIRCE nanosatellites will fly in a lead-follow tandem configuration in co-planar near-polar orbits at 500km altitude. Provided by Blue Canyon Technologies (BCT), the two buses will use differential drag to achieve and maintain an in-track separation of between 250 and 500km, allowing short time-scale dynamics to be observed in-situ. These nanosatellites each carry a complement of 5 individual scientific instruments, contributed from academic, industrial, and government partners across the UK and US. Scheduled to launch in 2021 via the US Department of Defence Space Test Program, the two CIRCE satellites will provide observations to enable a greater understanding of the driving processes of geophysical phenomena in the ionosphere/thermosphere system, distributed across a wide range of latitudes, and altitudes, as the mission progresses

Millimeter-scale RF Integrated Circuits and Antennas for Energy-efficient Wireless Sensor Nodes

Recently there has been increased demand for a millimeter-scale wireless sensor node for applications such as biomedical devices, defense, and surveillance. This form-factor is driven by a desire to be vanishingly small, injectable through a needle, or implantable through a minimally-invasive surgical procedure. Wireless communication is a necessity, but there are several challenges at the millimeter-scale wireless sensor node. One of the main challenges is external components like crystal reference and antenna become the bottleneck of realizing the mm-scale wireless sensor node device. A second challenge is power consumption of the electronics. At mm-scale, the micro-battery has limited capacity and small peak current. Moreover, the RF front-end circuits that operates at the highest frequency in the system will consume most of the power from the battery. Finally, as node volume reduces, there is a challenge of integrating the entire system together, in particular for the RF performance, because all components, including the battery and ICs, need to be placed in close proximity of the antenna. This research explores ways to implement low-power integrated circuits in an energy-constrained and volume constrained application. Three different prototypes are mainly conducted in the proposal. The first is a fully-encapsulated, autonomous, complete wireless sensor node with UWB transmitter in 10.6mm3 volume. It is the first time to demonstrate a full and stand-alone wireless sensing functionality with such a tiny integrated system. The second prototype is a low power GPS front-end receiver that supports burst-mode. A double super-heterodyne topology enables the reception of the three public GPS bands, L1, L2 and L5 simultaneously. The third prototype is an integrated rectangular slot loop antenna in a standard 0.13-μm BiCMOS technology. The antenna is efficiently designed to cover the bandwidth at 60 GHz band and easily satisfy the metal density rules and can be integrated with other circuitry in a standard process.PHDElectrical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/143972/1/hskims_1.pd