Testing method for 433 MHz antenna

　　Standing Wave Ratio (VSWR) Test:

　　Measure the standing wave ratio (VSWR) of an antenna using a vector network analyzer (VNA). VSWR is an important parameter for measuring the degree of antenna matching, and it is usually desirable for VSWR to be less than 2.

　　Connect the port of VNA to the input end of the antenna, set the frequency range of VNA to around 433 MHz, scan and record the VSWR curve.

　　Return Loss Test:

　　Using VNA, measure the return loss of the antenna. Return loss is a parameter used to measure the reflected energy of an antenna, and it is usually desirable for the return loss to be greater than 10 dB.

　　Set the frequency range of VNA to around 433 MHz, scan and record the return loss curve.

　　Antenna gain test:

　　Conduct comparative testing using standard gain antennas and spectrum analyzers. Place the test antenna and the standard gain antenna in the same testing environment.

　　Fix the antenna to be tested, open the directional pattern testing program, set the starting frequency of the test to 433 MHz, and measure the S21 amplitude P1 of the antenna to be tested.

　　Remove the antenna to be tested, place the standard gain antenna in the same position, and measure the S21 amplitude P0.

　　Calculate the gain of the tested antenna: G=P1/P0+G0, where G0 is the gain of the standard gain antenna.

　　Direction diagram test:

　　Measure the directional pattern of the antenna using a turntable and spectrum analyzer. Fix the antenna to be tested on the turntable and set the frequency of the spectrum analyzer to 433 MHz.

　　Rotate the turntable, record the S21 amplitude at different angles, and draw the directional diagram of the antenna.

　　Radiation efficiency test:

　　Measure the input impedance and reflection coefficient of the antenna using a network analyzer, and calculate the radiation efficiency of the antenna.

　　Radiation efficiency can be calculated by measuring the input power and radiation power of the antenna, where radiation efficiency=radiation power/input power.

　　Spectrum analysis:

　　Measure the transmission signal spectrum of the antenna using a spectrum analyzer. Connect the spectrum analyzer to the output end of the antenna, set the frequency range of the spectrum analyzer to around 433 MHz, and observe the spectrum characteristics.

　　Environmental testing:

　　Test the performance of the antenna in different environments, such as indoor, outdoor, open areas, etc., to evaluate its performance in practical applications.

　　Through the above steps, the performance of the 433 MHz antenna can be comprehensively evaluated to ensure its normal operation in practical applications.