## 1 Introduction  
Synthetic aperture radar (SAR), which can provide high-resolution earth images regardless of weather conditions or time of day has recently been used in various fields of domestic and international observation satellites [1; 2]. In the case of SAR antennas, to maximize resolution and power gain in acquiring high-resolution images, a large deployable panel is accommodated. However, to deploy such a large space deployment structure in orbit, it is essential to use specific mechanisms that allow the structure to be appropriately folded and stored inside the launch-vehicle fairing and fully deployed in orbit [1; 2; 3; 4; 5; 6]. Furthermore, when a satellite performs a mission, line-of-sight (LOS) pointing stability must be secured. During ground imaging, if the relatively large antenna is shaken by external or internal disturbances, the quality of the captured images will be degraded. Therefore, the stiffness of the rotational spring hinges of deployable panels is often increased in order to obtain high deployment stability. This mechanism shortens the deployment time but leads to a high impact load when fully deployed and latched. This deployment impact load could cause damage to structures, payloads, and solar cells. By contrast, decreased stiffness of the rotational spring hinges reduces the deployment impact load by increasing the deployment time, but cannot guarantee successful full deployment due to harness resistance and mechanical friction of deployment devices at low temperatures [7]. In response to these issues, a variety of methods have been proposed to allow stable deployment and reduce deployment impact loads, such as a torsion spring-latching hinge [8], tape spring hinge [9], and shape memory alloy (SMA)-based hinge [10]. However, these deployment mechanisms still have limitations including low deployment stiffness of the relatively large deployable structures. To address this, truss-link mechanisms [11] have been applied to many satellite missions to increase the deployment stiffness: ERS-1 [12], RADARSAT-1 [13], RADARSAT-2 [14], RADARSAT-Constellation [15], ALOS-2 [16], SEASAT [17], WorldView-4 [18], and Sentinel-5P [19]. Among these, the RADARSAT mission employed the truss-link mechanism to increase deployment stiffness and attempted to reduce the number of truss-links as the follow-up mission progressed to reduce weight. Comparing the number of truss-links in satellites, RADARSAT-1 (1995) has 30 links, RADARSAT-2 (2007) has 22 links, and RADARSAT-Constellation (2019) has four links. The reduction in the number of links is the result of a trend to build up small satellites for constellation missions. In addition, the applications of the truss-link mechanisms have been diversified. [PERSON] et al. proposed a pyramid deployable truss structure (PDTS) design for deployable SAR antennas through an analytical approach based on weighted graphs and kinematic chain techniques [20]. They also proposed a modular deployable truss structure (MDTS) for large SAR antennas [13] with a scaled model. A difference was found between the deployment test and the simulation, however, due to uneven and indeterminate ground friction as well as joint friction. Furthermore, to eliminate interference during the deployment process of the truss structure, the optimal motor driving torque was determined through the design of experiments (DOE) method. [PERSON] et al. proposed a large-scale deployable ring truss that composes a space antenna by complementing a rope-based actuation and cable net system [21]. Based on the absolute node coordinate formulation (ANCF), a method for simulating the rigid body motion of the antenna support arm was proposed, and the friction and motion equations of the flexible cable net were presented using the Lagrange equation. Most of the aforementioned works essentially assume that an active driving mechanism such as motors with cables is employed for large-scale SAR antenna structures.