In modern communication technology, the design of the direct broadcast satellite (DBS) antenna feed system is the key to achieving high efficiency and low loss. This paper will start from the basic principles, design methods and optimization paths of the antenna feed system to explore how to achieve the goal of high efficiency and low loss in the DBS band.
1. Basic principles of antenna feed system
The antenna feed system is a bridge between the antenna and the RF front end. Its main task is to transmit the RF signal from the antenna to the receiving device while minimizing signal loss and interference. The design of the antenna feed system needs to consider key parameters such as frequency range, bandwidth, gain, and standing wave ratio (VSWR).
For example, in the design of DBS antennas in the Ku band, the feed system usually adopts microstrip line feeding and forms a low-loss feeding network through waveguide combination.
2. Key factors for high-efficiency design
2.1 Optimization of gain and bandwidth
An efficient antenna feed system needs to strike a balance between gain and bandwidth. For example, a study designed a Ku-band antenna with a gain of 28.4-31.3 dB in vertical and horizontal polarizations, respectively, and a bandwidth covering the entire downlink frequency band. This design achieves efficient radiation performance by optimizing the size and weight of the subarray and waveguide feed network.
2.2 Low-loss feed network
The loss of the feed network directly affects the overall performance of the antenna system. Studies have shown that the use of low-loss shielded feeders and precision mold production can significantly improve the electrical performance of the antenna. In addition, by introducing technologies such as defective ground structure (DGS), the radiation efficiency can be improved without increasing the size of the antenna.
2.3 High-precision processing and optimization
The performance of the antenna feed system also depends on the processing accuracy. For example, a study optimized the processing accuracy of key components such as horns, orthogonals, and twisted waveguides through high-frequency structure simulation software and finally achieved the goal of standing wave better than -3dB and cross-polarization discrimination better than 90%.
This high-precision processing method provides a reliable guarantee for high-performance antenna feed systems.
3. Implementation path of low-loss design
3.1 Use new transmission lines and dielectric materials
In order to reduce the loss of the feed network, new transmission lines and low-loss dielectric materials can be used. For example, some studies have significantly reduced the VSWR value and increased the XPD value by using new feed structures such as rectangular waveguides, ridge waveguides and circular waveguides. The application of these materials and technologies helps to reduce signal loss and improve system performance.
3.2 System-level optimization and simulation
System-level optimization is an important means to achieve low loss. Through electromagnetic simulation software (such as HFSS and CST), the performance of the antenna feed system can be predicted and optimized in the design stage.
For example, a study verified the design effect of the dual orthogonal port feed through simulation, and the results showed that the reflection loss and isolation were better than expected.
3.3 Experimental verification and iterative improvement
The combination of theoretical design and experimental verification is the key to ensure the success of low-loss design. For example, a study verified the performance of the new feed network through actual measurement, and the test results showed that the reflection loss and isolation were better than the design target.
This method of experimental verification and iterative improvement can effectively improve the actual performance of the antenna feed system.
4. Conclusion
The design of the DBS band antenna feed system needs to comprehensively consider key parameters such as gain, bandwidth, and standing wave ratio and achieve the goals of high efficiency and low loss by optimizing the feed network, adopting new materials and technologies, and system-level simulation and experimental verification. Future research can further explore the application of new materials and more efficient optimization algorithms to meet higher performance requirements.
Through the above paths, we can achieve high efficiency and low loss antenna feed system in DBS band, providing more stable and reliable signal transmission guarantee for satellite communication.
Reference:
1. Microwave Systems and Applications. Sotirios K. Goudos.
2. Design of a Ku Band Planner Receive Array for DBS Reception Systems
[2017-01-11]
3. Earth Station Antenna. AlphaSatcom.
4. Optimization of the 0.35-1.05 GHz Quad-Ridged Flared Horn and Eleven Feeds
5. Modifikasi Antena Mikrostrip Berbasis Defected Ground Structure (DGS) Berbentuk Patch Puzzle