Research On Wireless Temperature And Pressure Sensor Antenna And Its Matching Circuits

In high-speed driving,tire failure is the most worrying and most difficult problem to prevent for all drivers,and it is also an important cause of sudden accidents.How to prevent the car during the process of high-speed puncture has become an important subject of safe driving,studies have shown that keep standard tire air pressure drive,timely find flat tires and tire real-time temperature monitoring is the key to prevent blowout,thus TMPS automobile tire pressure monitoring system arises at the historic moment,however,antenna temperature pressure sensor in the monitoring system plays an important role in information transmission,is car tire monitoring system can be the key to the real-time and accurate warning.Therefore,this paper studies the temperature and pressure sensor antenna.Firstly,based on the research status of the antenna module in the tire monitoring system at home and abroad.The actual working environment of the temperature and pressure sensor antenna in the monitoring system is analyzed.The constraints of the antenna design are clarified,and the microstrip antenna is determined as the basis of the sensor antenna design.A microstrip antenna is used as an example to analyze the antenna performance indicators,including antenna input impedance,S parameters,reflection coefficient,standing wave ratio,efficiency,pattern,gain,and antenna bandwidth.The four basic structures of microstrip antennas are summarized.At the same time,the design constraint conditions of the matching network loaded at the antenna input end and the basic circuit topology are also summarized and compared,and the design steps of the matching network in the Smith chart are explained in detail.Secondly,based on the basic theory of the microstrip antenna,two PCB printed microstrip antennas with an operating frequency of 433.92 MHz are designed.The first antenna adopts the scheme of single-side serpentine structure,which is a new antenna structure based on the deformation of the traditional inverted L-type printed microstrip antenna.The bending technology is used to increase the effective current path length.Under the premise of not increasing the antenna layout space,the antenna can be operated at a frequency of 433.92 MHz.The second antenna uses a double-sided loop structure.Its structure uses metalized vias to connect the front and back antennas,which can increase the effective current path length of the antenna and greatly reduce the antenna layout space.The premise is that the antenna works at a frequency of 433.92 MHz.The simulation results show that the return loss S11 of the two sensor antennas at the center frequency of 433.92 MHz is-21.64 dB and-18.74 dB,respectively,and the effective gains are-6.21 dBi and-7.72 dBi.Finally,a real object was produced according to the antenna simulation model.The antenna pattern was tested in a microwave anechoic chamber,and the S-parameters of the antenna were tested using a vector network analyzer.The measured results are consistent with the simulation results.In order to further verify the radiation characteristics of the antenna in the detection system,the designed antenna was loaded into a monitoring system,and a spectrum analyzer was used to perform an indirect test on the antenna radiated power.Test results show that the radiated power of the antenna can meet the design requirements within the distance of 50 cm to 150 cm.The above work of this paper is the analysis,design,and implementation of wireless sensor antenna and its matching circuit.The results are of great significance to the research and development of sensor antenna.