Value chain · CLM-1176
In plain terms
Each transmitting element on the satellite is a small cluster of three short rod antennas standing a quarter of a wavelength apart, all pointing along the long axis of the helix. They pass through a flat layer at their middle, which feeds them and acts as their ground plane.
The claim as recorded
Each CASSIOPeiA antenna element is three parallel dipoles, set a quarter wavelength apart and aligned with the helix axis, fed at the centre where they pass through a layer. SRC-026 says "Each element comprises three omnidirectional antennae (such as [1/2 lambda] dipoles) with centres spaced approximately [1/4 lambda] apart". It says that for half-wave dipoles "the attachment point is the central electrical feed, making each layer also the local ground plane for its associated elements". The patent gives, as a preference, "a triangular arrangement of three parallel dipoles, spaced one-quarter wavelength apart from each other". It places each dipole's axis "in parallel with a common central axis of the array".
Evidence behind this: Two sources by the concept's inventor: a T2 journal paper (SRC-026) and a T3 patent (SRC-088); the weaker sets the tier. Both describe the intended element; neither reports a built CASSIOPeiA element.
Scope and limits
A DESIGN DESCRIPTION, NOT A BUILT ELEMENT. The paper's "such as [1/2 lambda] dipoles" and the patent's "In a preferred arrangement ... may comprise" are both permissive; the patent also allows "a dipole or a folded dipole" (PDF 17). No element dimension in metres is stated; any length in mm is arithmetic on a chosen frequency. The CASSIE breadboard (SRC-001 PDF 4, Fig 6) used one printed "patch dipole" per unit cell, not a triplet, and must not be cited as a built instance of this element. That the half-wave dipole reads as two quarter-wave monopoles either side of the layer rests on SRC-026's own later phrase "each monopole" (PDF 4, see CLM-1177), not on a statement that it is one.
What it assumes
That the patent's element and the paper's element are the same design; both are by the same inventor, and SRC-026 PDF 1 says the antenna is under "worldwide patent applied".
Where it comes from
PDF 4 [173], raw, transliterated: "Each element comprises three omnidirectional antennae (such as [1/2 lambda] dipoles) with centres spaced approximately [1/4 lambda] apart." Same page, raw, transliterated: "For [1/2 lambda] dipole antennae, the attachment point is the central electrical feed, making each layer also the local ground plane for its associated elements." SRC-088 PDF 17 [5], raw: "In a preferred arrangement, each of the elements of the array may comprise a triangular arrangement of three parallel dipoles, spaced one-quarter wavelength apart from each other." (the same wording is claim 11, PDF 36). SRC-088 PDF 28 [16], raw: "The axes of each dipole 104 of the antenna elements 102 are aligned in parallel with a common central axis of the array 100".
Basis: antennas per element; spacing and length in wavelengths
Cite this
energyaperture.com/c/clm-1176
CLM-1176, Energy Aperture, as of 2019.
Connected records
Other published records linked to this one. A list, not a judgement.
- Also from SRC-026
- CLM-0004The author of the 2019 CASSIOPeiA paper states the beam's strongest point is about 230 watts per square metre, and says that figure was...CLM-0006None of the five main studies mentions the international radio-frequency exposure limits, or any safety standard, or a restricted area...CLM-0013The paper that modern UK studies rely on for the beam figure calls anything below 1 kilowatt per square metre safe, with 230 watts per...CLM-0336Different design studies over four decades have each simply assumed a different working lifetime for a solar power satellite, from about 15...CLM-0339A 2019 paper said solar power satellites are often assumed to need visits in orbit for repairs and refuelling, but that no system yet...CLM-0441A normal geostationary satellite needs a small, regular fuel-based nudge every year to stay in place. One 2019 design proposes cutting most...CLM-0504None of the main CASSIOPeiA-related documents in the register mentions any named safety or exposure standard, or describes any restricted...CLM-0660The 2019 CASSIOPeiA paper does not discuss electric propulsion for getting the satellite to its orbit. It only prices delivery using...More on the source page.
- Also from SRC-088
- CLM-0896The patent describes measuring the incoming steering signal at scattered sensors, not at every antenna, and working out the values in...CLM-0897The satellite aims its beam by listening for a low-power signal sent up from the receiving station, measuring the shape of that arriving...CLM-0899The patent never says the steering signal is protected in any way. There is a difference between scrambling that signal so nobody can read...CLM-0900The satellite can point its beam far further than there is Earth to point at, so moving power from one receiving station to another is not...CLM-0903The shared clock tells every sensor to take its reading at the same moment. How precise that clock must be depends on how fast the thing...CLM-0905Sharing a clock is not the same as being told what to do. The clock and the carrier tell the antennas nothing about where to send the power...CLM-0913When the satellite corrects its own bending by listening to the ground signal, what is left over is not how far the antennas moved. It is...CLM-0942Three documents held here give three different sizes for the same satellite's transmitting antenna. The patent says 1 to 1.5 km across and...More on the source page.