NEWS

Satellites use high frequencies (e.g., Ku/Ka bands, 12–40GHz) for wider bandwidth (hundreds of MHz vs. tens in L-band), enabling higher data rates; shorter wavelengths allow compact antennas, reducing launch weight while minimizing terrestrial interference. Why High Frequency Matters High-frequency bands, typically classified as those above 3 GHz, such as Ku-band (12–18 GHz) and Ka-band (26.5–40

Yagi antennas are directional, with a driven element, reflector, and directors, offering 10–15dBi gain at 2.4GHz for focused point-to-point links. Omni antennas radiate uniformly horizontally (2–5dBi gain), suited for area coverage; Yagi typically operates 400MHz–6GHz, Omni 30MHz–6GHz, differing in pattern and use case. How They Send and Receive Signals A Yagi antenna, like a flashlight,

Coupler antennas integrate signal routing and isolation functions, enabling power division (e.g., 10–20dB splits) or sampling (insertion loss <0.3dB) between transmit/receive paths while maintaining >25dB isolation at 2–18GHz to minimize interference, optimizing RF system efficiency. Connecting Two Devices Wirelessly A common challenge in RF systems is efficiently transferring a signal from a primary transmitter to

The C-band, defined by ITU as 4-8 GHz, faces practical limits: rain fade at 100mm/h induces 0.5-1dB/km loss at 6GHz, impacting satellite links (uplink 5.925-6.425GHz, downlink 4.6-5.0GHz). Antenna gain (30-40 dBi for 3-6m dishes) and LNA noise figures (0.5-1.5dB) constrain sensitivity, while physical size limits high-gain use in compact systems. Defining C-Band Frequency Range The

Satellite antennas operate via parabolic reflectors that focus electromagnetic waves onto a feed horn; a 3-meter diameter dish in Ku-band (12-18GHz) achieves ~40dBi gain, directing signals toward satellites. During transmission, electrical signals convert to waves at the feed, reflected into parallel beams by the parabola; reception reverses this, focusing incoming waves (error <0.1° in azimuth/elevation)

To test a directional coupler, connect it to a signal generator (output: +10dBm, 2-4GHz) and spectrum analyzer. Measure input power (Pin) at the main port, coupled power (Pcouple) at the coupled port, and isolated port power (Piso). Calculate insertion loss (Pin-Pthru, typical 0.5-2dB), isolation (Pin-Piso ≥20dB), and directivity (Pcouple-Piso ≥30dB) to validate performance. Measure Insertion