## 1 Introduction  
The transmitarray design technique is actively studied based on the advantage of allowing various functions such as focusing, splitting, and multi-beam generating an electromagnetic (EM) wave emitted from a source antenna or controlling linear and circular polarization without a complex power distribution network when located at the front of a passive legacy antenna [1]. An EM structure commonly used to enable such functionality is a technique of controlling a frequency response attribute by including active elements such as the electromagnetically controllable PIN, varactor diode, or microelectromechanical systems (MEMES) in a periodic configuration that resonates at a specific frequency such as a reconfigurable frequency selective surfaces (FSS) structure [2; 3; 4] and reconfigurable metamaterials (MM) [5; 6; 7; 8; 9; 10]. As a part of research to develop a high-speed, stable wireless communication technology in a high-density, complex communication environment, the core technology of a point-to-point communication system that can minimize the effect of interference from multipath or a heterogeneous device by tracking and relaying signals to a user or an object from a base-station was developed for application in private sectors [11; 12; 13]; separate research on a design technique for a low SWaP-C radar for air or ground surveillance or unmanned aerial vehicles (UAV) continues to be applied in the defense sector [14]. Multi-functional reconfigurable transmitarray was implemented in this study by periodically arranging the reconstruction of a unit cell's frequency response characteristics using the 1-bit ON/OFF switch attributes of the PIN diode. Reconfigurable transmitarray, based on an active element that can be electromagnetically controlled, can be classified into two methods. The first is switching the polarization from vertical to vertical or vertical to horizontal by controlling the direction of the electric current by including the periodic configuration of a unit cell with a frequency-selective penetration characteristic of an active element [8] or creating a high-gain beam pattern and beam steering function by controlling the path length of an induced current using a variable capacitor [2; 3; 4; 5; 7; 13]. The second is a design method that collects the external incidence of an EM wave through a patch arranged in a periodic configuration and makes the beam steering and polarization conversion (PC) function possible by controlling the phase and direction of the directed electric current which is then reemitted [12; 14; 15; 16; 17; 18; 19; 20; 21]. Because of the design that includes active elements that directly affect the characteristic impedance of periodically arranged unit cells, the former method facilitates an intuitive design with a relatively simple configuration, which has the advantage of realizing the low-loss reconstruction characteristics. However, there is a disadvantage in that a multi-layer structure of five or more layers is required to secure the broadband response in consideration of the resonance frequency change that varies according to the value. The latter is a method of reconstructing the EM characteristics via the unit cell's periodic arrangement with a receiver patch-active circuitry-transmitter patch construction and has the benefit of realizing a multi-function based on a stable frequency characteristic by introducing a phase shifter circuitry for the beam shifting functionality or polarization switching circuitry into the part of active circuitry. In addition to the increased design complexity, phase shifter circuitry is limited in that a sufficient area or number of unit cell layers must be secured to realize a wide dynamic range of the available phase-shifting range while suppressing parasitic resonance [18; 22].