Microwave and millimeter-wave backhaul links play a vital role in modern communication networks by enabling high-capacity data transmission over distances ranging from hundreds of meters to several kilometers. These systems typically operate in high-frequency bands above 10 GHz, where a wider bandwidth is available. While such frequencies support compact antenna design and reduced interference through highly directional beams, they are also more susceptible to propagation losses and atmospheric effects, particularly rain attenuation. This paper presents a systematic analysis of microwave link budget design and rain attenuation mechanisms. Fundamental link budget calculation methods are introduced based on free-space propagation models, along with key system gain and loss factors. Rain attenuation is examined through established modeling approaches, and its impact on link reliability is analyzed under different environmental conditions. In addition, regional characteristics and advanced applications, including rainfall inversion and radar correction, are discussed to demonstrate the broader relevance of microwave link analysis. Furthermore, the study explores satellite laser communication as an emerging complementary technology. Compared with conventional microwave systems, laser communication offers significantly higher data rates, larger bandwidth, and enhanced security. However, it is more sensitive to atmospheric conditions. Therefore, a hybrid communication framework combining microwave and laser technologies is considered to improve overall system robustness and performance. The results indicate that accurate link budget modeling and effective mitigation of rain attenuation are essential for reliable high-frequency communication. Moreover, the integration of microwave and laser communication technologies is expected to play a key role in future satellite-terrestrial networks, particularly in the development of 6G systems.