Research On Loran C Miniaturized Active Receiving Antenna

Roland C is a land-based radio navigation system.Roland C signal has strong anti-interference ability and signal stability during the transmission.At present,navigation mainly relies on satellites for navigation,but satellite navigation is affected by natural conditions,and Roland C navigation system can be used as a backup for satellite navigation systems.First,before designing the antenna,the characteristics of the signal to be received should be analyzed.Combining the design requirements with the choice of antenna,this type of antenna can usually be designed in the form of an electrical or magnetic antenna.The magnetic antenna receives signals with strong anti-interference ability,and can better achieve miniaturization goals.It is determined to use magnetic antenna forms for design.The design of the magnetic antenna will involve the selection of magnetic bar characteristics,coil density and other factors.In addition,in order to improve the quality of the signal,the received signal is connected to the circuit,and active circuit design is also performed.The research work of this paper includes the following aspects:(1)Analyze the basic theory of magnetic materials and select the best performance magnetic material.The structure of the magnetic rod is studied so that the structure can better satisfy the performance of the antenna.The basic composition of the coil is studied,the influence of the coil on the antenna in different forms is analyzed,and the mutual relationship between the magnetic rod and the coil as a whole is studied.In addition,in order to ensure omnidirectional reception,it is necessary to use a magnetic rod antenna for array formation.(2)Due to the Roland C signal form requirements,a bandpass filter with a center frequency of 100 kHz and a bandwidth of 20 kHz was designed.In this low frequency band,an active filter is used.The active filter ensures that the antenna can only receive the signal at this frequency,and has a good suppression effect outside the band.(3)The receiving signal of the magnetic antenna is very weak.In order to ensure the amplitude of the post-stage signal without introducing noise,the circuit composed of the AD8421 chip is used to amplify the signal;the adder circuit is designed to synthesize the signal received by the four-way magnetic antenna.Finally,the design of the radome is performed.The radome can place a magnetic bar and a fixed active circuit.After all the designs are completed,the antenna is fabricated and tested to meet the requirements.Finalized the research and design of Roland C miniaturized receiving antenna...