A Method for Measuring the Actual Output Impedance of a Transmitter

Abstract

The invention relates to the technical field of communication equipment application, in particular to a method and system for measuring the actual output impedance of a transmitter, which is suitable for a system in which an antenna tuner is used to realize impedance matching between a transmitter and an antenna. Including: the antenna tuner generates the first micro-power signal, performs the first micro-power tuning on the transmitter and the antenna, so that the transmitter and the antenna achieve impedance matching, and records the first load impedance of the antenna after the impedance matching of the transmitter and the antenna; keeps the antenna The parameters of the tuner remain unchanged, the transmitter transmits a high-power radio frequency signal of a specific frequency, and records the first voltage standing wave ratio; the first load impedance and the first voltage standing wave ratio are used as the first set of reference data; the above process is repeated to obtain The second set of reference data obtains the actual output impedance of the transmitter according to the first set of reference data and the second set of reference data.

Description

technical field [0001] The invention relates to the technical field of communication equipment application, in particular to a method for measuring the actual output impedance of a transmitter, which is suitable for a system in which an antenna tuner is used to realize impedance matching between a transmitter and an antenna. Background technique [0002] The effect of short-wave communication is closely related to factors such as antenna bandwidth, gain, standing wave ratio, and directivity. Therefore, in short-wave communication, it is extremely important to choose a good antenna to improve the communication effect. In the short-wave frequency band, due to the large band coverage and strong changes in antenna parameters, it is difficult to use a conventional broadband matching network to achieve fast impedance matching for various antennas. The short-wave transmitter must use an antenna tuner to complete the impedance of the transmitter and antenna before working. Matching...

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Problems solved by technology

[0004] In practical applications, it is found that the frequency point where the antenna tuner successfully tunes with micropower has a relatively small standing wave (matched to around 50Ω), but when transmitting at high power, the standing wave ratio becomes larger, resulting in a larger reverse power of the transmitter , the radiation efficiency of the antenna feed system is reduced

When the standing wave ratio becomes larger and the antenna system has no resonance, there is a large reactive component in the impedance, which may cause damage to the RF final power device, vacuum device and electron tube inside the transmitter.

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