KU Feedhorns and Solutions for C-Band Antennas

Description

KU Feedhorns and Solutions for C-Band Antennas

Introduction to KU Feedhorns and Solutions for C-Band Antennas Receiving KU-Band Signals

1. Key Features of KU Feedhorns

KU feedhorns are integrated devices used for transmitting and receiving signals in the KU-band (10.7-12.75 GHz) in satellite communications. Their core features include:

• Dual-Polarization Design
  • Support both dual circular polarization and dual linear polarization modes, enabling polarization switching via built-in circular polarizers or detachable polarizers. For instance, certain models can convert to dual linear polarization by removing the circular polarizer and adding a filter to meet diverse communication needs.
  • Cross-polarization levels below -40 dB ensure high polarization isolation, minimizing signal interference.
• Compact Structure and High Efficiency
  • Adopt a coaxial nested structure, offering a compact size suitable for small-aperture antennas (e.g., 1.2-meter offset antennas).
  • Symmetrical radiation patterns and gains up to 49 dB (e.g., with a 1.2-meter offset antenna and F/D=0.6) support high-sensitivity signal reception.
• Multi-Scenario Applications
  • Applicable in satellite TV reception (e.g., high-definition and standard-definition programs on ChinaSat 9), radar systems, and wireless communications.
  • In radar systems, they concentrate illumination on target areas, enhancing detection accuracy.

2. Solutions for C-Band Antennas Receiving KU-Band Signals

To utilize C-band antennas for KU-band signal reception, the following approaches can be employed:

• Dedicated KU-Band Feedhorns
  • High-Gain Split Feedhorns: Models like YLK-KU-01 cover 10.7-12.75 GHz, support single polarization, and feature WR75 interfaces compatible with mainstream split LNBs (e.g., CyberSat, Norsat).
  • Multi-Ring Efficient Feedhorns: Some designs use a 9-ring trapezoidal structure to optimize signal collection efficiency, specifically tailored for C-band antennas equipped with KU-band LNBs.
• Dual-Feed Cassegrain Antennas
  • Design Principle: The main reflector is a paraboloid, and the sub-reflector is a hyperboloid. Frequency-selective surfaces (FSS) enable C-band signal transmission and KU-band signal reflection. For example, dual circular-ring FSS units can simultaneously transmit C-band (3700-4200 MHz downlink, 5925-6425 MHz uplink) and KU-band (12200-12750 MHz downlink, 14000-14500 MHz uplink) signals.
  • Application Scenarios: Ideal for ground stations requiring simultaneous C/KU-band reception, reducing construction costs.
• Offset Antenna Adaptation Solutions
  • High-Efficiency Offset Feedhorns: Designed for offset antennas (e.g., three-ring or five-ring structures), these optimize signal reception efficiency by precisely controlling corrugation ring depths and spacings. For instance, a three-ring efficient feedhorn, crafted from aluminum alloy die-casting, features a 15.9 cm diameter and meticulously adjusted corrugation parameters for offset antenna systems.

3. Key Technical Parameters and Selection Guidelines

• Operating Frequency and Polarization
  • Ensure the feedhorn’s frequency range covers the target KU-band signals (e.g., 10.7-12.75 GHz).
  • Choose single- or dual-polarization feedhorns based on signal polarization, noting flange positions (coplanar or perpendicular) for dual-polarization models.
• Interface Compatibility
  • The feedhorn interface must match the LNB (e.g., WR75 for split LNBs).
  • Select multi-port LNBs for simultaneous multi-channel reception.
• Gain and Noise Performance
  • Prioritize feedhorns with high gain (≥49 dB) and low noise temperature to enhance signal quality.
  • Refer to practical test data, such as dual circular-ring FSS units exhibiting transmission losses below -0.84 dB for C-band downlink and reflection attenuation below -0.35 dB for KU-band.