A quadruple subharmonic phase-conjugating array for secure picosatellite crosslinks

Retrodirective Array Immune to Incident Waves With Arbitrary Polarizations

“…In order to alleviate the high LO frequency, phase-conjugation through sub-harmonic mixing is widely used [12], [13], [20]. Sub-harmonic mixing is advantageous for the proposed RDA not only to reduce the overall system cost and provide higher port-to-port isolation, but also to minimize potential phase errors along the LO path.…”

Miniaturized Retrodirective Arrays for a Nanosatellite Platform

“…Although retrodirective arrays have been in development for the past 50 years [2], [3], integrating an RDA into a CubeSat represents a challenge due to the strict SWaP requirements. The first RDA developed for a CubeSat platform [14], [15] achieved retrodirectivity using the heterodyne technique [10], where mixers are used to phase conjugate the received signal. The biggest drawback to this type of RDA architecture is that the signal strength at the output of the array is dependent on the incoming signal strength, and thus the distance from the interrogator.…”

A 2-D Phase-Detecting/Heterodyne-Scanning Retrodirective Array

“…2-D steering is critical for applications such as inter-satellite communications [15], where relative positions of the satellites are affected by satellite altitude/attitude and orbit inclination. Only a limited number of 2-D retrodirective arrays have been demonstrated to date (e.g., [16] and [17]), but they are all susceptible to the roundtrip path loss.…”