Impedance matching method of telemetry, track and command (TT&C) antenna

Abstract

The invention relates to an impedance matching method of a telemetry, track and command (TT&C) antenna. The method that a deployment cap is added at the top end of an antenna feeder tube is adopted to change electric field distribution in the feeder tube and to regulate the position of a voltage minimum point, and then a quarter-wave impedance matching tube is utilized to perform standing-wave ratio (SWR) regulation so as to enable the SWR of the quadrifilar helix TT&C antenna to be smaller than 1.2, and the problems that the voltage minimum point of the quadrifilar helix TT&C antenna exceeds the top end of the feeder tube and the quarter-wave impedance matching tube can not be utilized to perform the SWR regulation are solved. In addition, the structure of the deployment cap is designed ingeniously, and reliable connection is enabled to be formed between the deployment cap and the top end of the feeder tube; and optimization design is performed on material of the deployment cap, and therefore the deployment cap is enabled to be small in size and light in weight, and has no effect on other electrical performance of the antenna and the structural reliability.

Description

technical field [0001] The invention relates to an impedance matching method of a measurement and control antenna, which belongs to the field of space-borne measurement and control antennas. Background technique [0002] The four-arm helical measurement and control antenna usually adopts the coaxial feeding method. To match the impedance of the helical antenna with the 50Ω RF input signal and reduce the mismatch loss, a matching tube is usually added at the minimum point of the feeding tube voltage. By adjusting the matching tube The diameter and length are adjusted for impedance, so that the voltage standing wave ratio of the four-arm helical measurement and control antenna is less than 1.5. The limitation of this impedance adjustment method is that the matching tube covers the inner conductor, so the minimum voltage point of the feeding tube must be within the actual size range of the inner conductor. [0003] Due to the short length of the feeder tube of the four-arm hel...

AI Technical Summary

Problems solved by technology

[0003] Due to the short length of the feeder tube of the four-arm helical measurement and control antenna, the minimum voltage point has exceeded the actual size range of the inner conductor and the top of the feeder tube, so it is impossible to adjust the standing wave ratio with a quarter-wavelength impedance matching tube.

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