A high-frequency signal transmission/reception device, comprising: a signal electrode that includes a form of a flat conductive plate and includes a plurality of matching elements disposed along an edge thereof; a ground electrode that includes a form of a flat conductive plate and is disposed parallel to the signal electrode; a dielectric layer between the signal electrode and the ground electrode; a plurality of photoconductive elements (1, 803, 804), each of which is electrically connected to the signal electrode and the ground electrode, arranged in a grid; an excitation signal feed point; and a plurality of load elements that are electrically connected to the plurality of matching elements, wherein: the photoconductive elements (1, 803, 804) are included in at least two states, the at least two states including a dielectric state with a low intrinsic electrical conductivity in absence of a control light flux, and a conductor state with a relatively high electrical conductivity in presence of a control light flux, the photoconductive elements (1, 803, 804) in the grid are arranged such that the photoconductive elements (1, 803, 804), to which a control light flux is applied at a given instant, form a curve close to a desired reflection profile of an excitation signal supplied from the excitation signal feed point, a distance between adjacent photoconductive elements (1, 803, 804) is less than a half of a wavelength of the excitation signal, and at least one of the signal or ground electrodes includes holes for providing control light fluxes to the photoconductive elements or for mounting conductive elements that connect the photoconductive element with another electrode. a signal electrode that includes a form of a flat conductive plate and includes a plurality of matching elements disposed along an edge thereof; a ground electrode that includes a form of a flat conductive plate and is disposed parallel to the signal electrode; a dielectric layer between the signal electrode and the ground electrode; a plurality of photoconductive elements (1, 803, 804), each of which is electrically connected to the signal electrode and the ground electrode, arranged in a grid; an excitation signal feed point; and a plurality of load elements that are electrically connected to the plurality of matching elements, wherein: the photoconductive elements (1, 803, 804) are included in at least two states, the at least two states including a dielectric state with a low intrinsic electrical conductivity in absence of a control light flux, and a conductor state with a relatively high electrical conductivity in presence of a control light flux, the photoconductive elements (1, 803, 804) in the grid are arranged such that the photoconductive elements (1, 803, 804), to which a control light flux is applied at a given instant, form a curve close to a desired reflection profile of an excitation signal supplied from the excitation signal feed point, a distance between adjacent photoconductive elements (1, 803, 804) is less than a half of a wavelength of the excitation signal, and at least one of the signal or ground electrodes includes holes for providing control light fluxes to the photoconductive elements or for mounting conductive elements that connect the photoconductive element with another electrode. the photoconductive elements (1, 803, 804) are included in at least two states, the at least two states including a dielectric state with a low intrinsic electrical conductivity in absence of a control light flux, and a conductor state with a relatively high electrical conductivity in presence of a control light flux, the photoconductive elements (1, 803, 804) in the grid are arranged such that the photoconductive elements (1, 803, 804), to which a control light flux is applied at a given instant, form a curve close to a desired reflection profile of an excitation signal supplied from the excitation signal feed point, a distance between adjacent photoconductive elements (1, 803, 804) is less than a half of a wavelength of the excitation signal, and at least one of the signal or ground electrodes includes holes for providing control light fluxes to the photoconductive elements or for mounting conductive elements that connect the photoconductive element with another electrode.