Method and apparatus for remotely determining antenna input impedance
OwnerMartin F. Jueinventor
Life of this patent
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Abstract
A system for remotely measuring antenna input impedance utilizing an automatic antenna tuner in which, for any tuner, the tuner input impedance may be established by the values of the components in the circuit at the time that the SWR is at a minimum, with these values being automatically available in terms of the components that are switched in to achieve low SWR. Once having established the input impedance to the tuner, the complex conjugate of the tuner input impedance yields the antenna input impedance, with antenna input impedance sensed at full power at a position remote from the antenna input.
Claims17
An apparatus for remotely measuring a feed point impedance of an antenna, the apparatus comprising:
- an automatic antenna tuner including capacitive and inductive components that are switched into a tuner circuit of the automatic antenna tuner to achieve a minimum standing wave ratio (SWR), wherein the automatic antenna tuner is configured to automatically sense a frequency of a transmitter communicatively coupled therewith;
- a processor for calculating the antenna feed point impedance based on the sensed frequency of the transmitter, values of the switched-in components that are utilized to achieve the minimum SWR, and a measured length of a feedline between the automatic antenna tuner and a feed point of the antenna;
- and
- a display coupled to the processor for displaying the calculated antenna feed point impedance.
A method for remotely sensing an antenna input impedance of an antenna coupled to a transmitter utilizing a feedline, the method comprising:
- utilizing an automatic antenna tuner to tune the antenna to the transmitter;
- and
- detecting the antenna input impedance utilizing characteristics of the automatic antenna tuner when the automatic antenna tuner has tuned to a minimum standing wave ratio (SWR), wherein:
- the automatic antenna tuner includes capacitive and inductive elements that are switched in to achieve the minimum SWR;
- and
- the detecting includes:
- utilizing values of the switched-in elements to compute the antenna input impedance;
- and
- measuring a length of the feedline between the automatic antenna tuner and an antenna feed point.
A method for remotely determining an antenna input impedance of an antenna by utilizing an automatic antenna tuner and deriving the antenna input impedance from characteristics of the automatic antenna tuner without utilizing an antenna analyzer, wherein the deriving utilizes:
- values of capacitive and inductive elements switched in to the automatic antenna tuner to achieve a minimum standing wave ratio (SWR);
- and
- a measured length of a feedline between the automatic antenna tuner and an antenna feed point for the antenna.
Dependencies are inferred from the claim text.