| 摘要 |
<p>PURPOSE: To enhance a power efficiency and to enable mounting and use of the antenna on a satellite by changing a usage of an active antenna element in transmission and reception and by making it a pattern optimum for each of transmission and reception. CONSTITUTION: An active transmission/reception (TR) module has a transmission input E, a transmission output S connected to an emission element of an antenna, a digital phase shifter 10 and a head-to-tail type parallel connection of a high power amplifier(HPA) 13 for transmission and a low noise amplifier(LNA) for reception between first and second switches 11 and 12. A gain control is given by adding one variable attenuator 15 behind the LNA 14 and controlling a gain in a final stage of the LNA 14, and the whole of the HPA 13 operates continuously in an output power. By making the HPA 13 operate in a region of compression or saturation thereof, accordingly, it is possible to maximize the output power and to optimize the efficiency thereof. The output switch 12 gives transmission-reception switching and two ports leading to the emission element (two polarizations: horizontal polarization H and vertical polarization V) at the same time.</p> |
