Analysis And Design Of Dual Frequency Self Tracking Feed

With the development of satellite communications to mobile and millimeter wave bands, the research of multi-band transceiver and self-tracking capability is becoming a hot topic in the research of satellite communication antenna, and to study the corresponding feed has become the key to solve these problems.Single pulse tracking is one of the ways to realize self-tracking,it can get the complete satellite deviation information from the comparison of the difference beam amplitude in each received pulse,and it has the characteristics of high tracking precision and good real-time performance.From this perspective,A Ku band dual circular polarization monopulse feed and a Ka dual band circular polarization monopulse feed is designed and simulated in this paper,and on this basis, the Ku/Ka dual band multi-mode monopulse feed is designed and simulated.Firstly, the Ku band circular polarization multi-mode monopulse feed based on coaxial waveguid is designed.The extraction of the received sum patterns and difference patterns depends on the improved TM01 mode coupler,and achieves eparation of sum patterns and difference patterns through the magic T network.Send and receive signals are rely on the magic T modulation to achieve circular polarization.The radiating aperture is in the form of conical multimode horn.Get a radiation pattern with good rotational symmetry and significant differential mode zero axial depth.Then,the Ku band circular polarization multi-mode monopulse feed is designed.The coupling probe at the end of the waveguide responsible for Receiving differential mode TM01 mode.Send and receive signals received through the same two orthogonal sets of rectangular waveguide coupling arm,and achieve circular polarization through the magic T modulation.To achieve transceiver isolation,a capacitor load Ka-band band-pass filter is designed.Radiation orofacial using the form of dielectric rod horn,Radiation pattern is good rotational symmetry,and with significant differential mode zero axial depth.Finally, on the basis of two feed designed,the Ku/Ka-band dual multimode monopulse feed is designed.Ka-band signal is bounded to prevent higher modes in the public segment through the dielectric rod waveguide,and the send and receive beams are formed through the end taper section of dielectric rod.Ku-band follow the multimode conical horn programs,increases the ladder match structure on the inner and outerconductor of the coaxial waveguide to prevent the Ku-band signaling an impedance mismatch to the public section.The feed has equivalent sum patterns and difference patterns with null at the axial direction on both bands, It can be achieved single pulse tracking on the two bands.