skip to main content

Title: A Dual-Band circularly polarized printed antenna for deep space CubeSat communication
This paper presents the design of a dual-band printed planar antenna for deep space CubeSat communications. The antenna system will be used with a radio for duplex operation in a CubeSat, which can be used for a lunar mission or any deep space mission. While a high-gain CubeSat planar antenna/array is always desired for a deep space mission, high-performance ground stations are also required for robust communication links. For such a mission, the X-band is the appropriate frequency for the downlink communication, which is very challenging in the case of deep space communication compared to the uplink communication. At this frequency, the antenna size can have small enough dimension to form an array to obtain high-gain directional radiations for the successful communication, including telemetry and data download. NASA’s Deep Space Network (DSN) has the largest and most sensitive 70 meterdiameter antenna that can be considered for this type of mission for reliability. DSN has uplink and downlink frequency of operations in 7.1-GHz and 8.4-GHz bands, respectively, which are separated by approximately 1.3 GHz. A straight forward approach is to use two antennas to cover uplink and downlink frequencies. However, CubeSats have huge space constraints to accommodate science instruments and other more » subsystems and commonly utilize outside faces for solar cells. Therefore, in this paper, we have proposed a planar directional circularly polarized antenna with a single feed that operates at both uplink and downlink DSN frequencies. Simulated 3-dB axial ratio bandwidth of 165 MHz, from 7064 MHz to 7229 MHz for uplink, and that of 183 MHz, from 8325 MHz to 8508 MHz for downlink, are achieved. Also, a wide impedance bandwidth of 23.86% (VSWR < 2) is obtained. From this single probe-fed stacked patch antenna, peak RHCP gain of 9.24 dBic can be achieved. « less
Authors:
; ; ; ;
Award ID(s):
1655280
Publication Date:
NSF-PAR ID:
10221593
Journal Name:
Small Satellite Conference, Logan, Utah
Sponsoring Org:
National Science Foundation
More Like this
  1. This paper presents a wideband circularly polarized antenna for small satellites to be used with NASA Near- Earth Networks (NEN). This single-fed stacked antenna utilizes the electromagnetic coupling concept and is usable with a duplex transceiver. The circularly-polarized antenna employs hybrid perturbations on stacked patches and covers NASA NEN’s both uplink and downlink frequencies, thus replacing the conventional requirement of two separate antennas. It provides a notable wide axial ratio (AR) < 3 dB bandwidth of 1.16 GHz from 7.02 GHz to 8.18 GHz (15.3%). The optimized patch dimensions provide 34.6% VSWR ~ 2 bandwidth from 6,525 MHz to 9,253 MHz. The overall antenna size is 17 mm × 17 mm × 6.6 mm, and has a peak gain of 7.9 dBi. This proposed antenna will overcome solar cell space constraint on smallsat’s outer wall by saving at least 50% area required by the conventional two-antenna method.
  2. Application of massive multiple-input multipleoutput (MIMO) systems to frequency division duplex (FDD) is challenging mainly due to the considerable overhead required for downlink training and feedback. Channel extrapolation, i.e., estimating the channel response at the downlink frequency band based on measurements in the disjoint uplink band, is a promising solution to overcome this bottleneck. This paper presents measurement campaigns obtained by using a wideband (350 MHz) channel sounder at 3.5 GHz composed of a calibrated 64 element antenna array, in both an anechoic chamber and outdoor environment. The Space Alternating Generalized Expectation-Maximization (SAGE) algorithm was used to extract the parameters (amplitude, delay, and angular information) of the multipath components from the attained channel data within the “training” (uplink) band. The channel in the downlink band is then reconstructed based on these path parameters. The performance of the extrapolated channel is evaluated in terms of mean squared error (MSE) and reduction of beamforming gain (RBG) in comparison to the “ground truth”, i.e., the measured channel at the downlink frequency. We find strong sensitivity to calibration errors and model mismatch, and also find that performance depends on propagation conditions: LOS performs significantly better than NLOS.
  3. Wireless networks at millimeter wavelengths have significant implementation difficulties. The path loss at these frequencies naturally leads us to consider antenna arrays with many elements. In these arrays, local oscillator (LO) generation is particularly challenging since the LO specifications affect the system architecture, signal processing design, and circuit implementation. We thoroughly analyze the effect of LO ar- chitecture design choices on the performance of a mm-wave massive MIMO uplink. This investigation focuses on the tradeoffs involved in centralized and distributed LO generation, correlated and uncorrelated phase noise sources, and the bandwidths of PLLs and carrier recovery loops. We show that, from both a performance and implementation complexity standpoint, the op- timal LO architecture uses several distributed subarrays locked to a single intermediate-frequency reference in the low GHz range. Additionally, we show that the choice of PLL and carrier recovery loop bandwidths strongly affects the performance; for typical system parameters, loop bandwidths on the order of tens of MHz achieve SINRs suitable for high-order constellations. Finally, we present system simulations incorporating a complete model of the LO generation system and consider the case of a 128-element array with 16x-spatial multiplexing and a 2 GHz channel bandwidth at 75 GHz carrier. Usingmore »our optimization procedure we show that the system can support 16-way spatial multiplexing with 64-QAM modulation.« less
  4. With space more accessible than ever, academic institutions like the University of Colorado (CU) Boulder have exhibited that CubeSats (compact, homogeneous, rectangular satellites with masses below 14 [kg]) can be leveraged for remarkable space missions capable of making significant advances to both scientific and technological fields. One such CubeSat project is the NSF-funded Space Weather Atmospheric Reconfigurable Multiscale Experiment (SWARM-EX), which will launch three 3U CubeSats into a “swarm” that will demonstrate autonomous formation flying capabilities while simultaneously studying the spatial and temporal variability of ion-neutral interactions in the equatorial Ionosphere-Thermosphere region. Although the small stature of CubeSats and their standardized deployer options help to lower unit development cost and facilitate launch opportunities, the physical size limits of CubeSats prove to be a double-edged sword vis-à-vis sustaining a stable power state while hosting instruments with high power demands and often strict pointing requirements. For SWARM-EX, this issue is magnified by the mission’s ambitious goals; to comply with mission requirements, a SWARM-EX spacecraft is required to concurrently (1) point the science instruments no more than 30° off ram when they are operational, (2) point the GNSS patch antenna no more than 30° off zenith when the spacecraft are separated by ≤more »10 [km], (3) point the X-Band patch antenna no more than 18° off boresight from the ground station during downlink, (4) maximize the differential ballistic coefficient during differential drag maneuvers, and (5) maximize solar array power generation at all times. Consequently, advanced CubeSat Missions like SWARM-EX require innovative systems engineering solutions to remain power-positive during on-orbit operations. Through a combination of intricate pointing profiles, orbital simulations, a comprehensive and coordinated ConOps, battery state of charge simulation tools, and expertise from previous CubeSat missions, the SWARM-EX team has conceived a plan to successfully meet all these mission requirements; it is the aim of the authors to illuminate these strategies as a case study.« less
  5. Due to the exponential growth of small satellite technology, novel shapes for antennas have been explored to make them low-cost, lightweight, compact, and easy to deploy. The use of frequency beam-scan antennas reduces the complexity of the small satellite front-end by avoiding the need to use phase shifters, especially when a reliable inter-satellite link (ISL) is required to keep up the communication and the formation accurately in a CubeSat swarm mission. This paper reports the design and a manufacturing process focused on in-space manufacturing (ISM) of a fully 3D-printed leaky-wave antenna, using ULTEM 9085 for aerospace applications. The antenna shows frequency beam steering capabilities from 4.4 GHz to 7.4 GHz, and a gain reconfigurable by angular rotation of the ground planes. The resulting antenna shows a measured peak gain of 10.07 dBi at 6.5 GHz, with a gain reconfigurability, as function of the elevation angle of the ground planes, in the range of 0 to 40°, providing an additional gain from 0 to 2 dBi, respectively.