| CPC H01Q 9/30 (2013.01) [H03J 5/02 (2013.01)] | 19 Claims |

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1. A method of operation of a compact frequency adjustable (CFA) portable antenna comprising:
measuring a frequency and a forward power value of broadcast transmission of the CFA portable antenna, the forward power measured at an RF input port of the CFA portable antenna;
calculating a valid frequency flag by comparing the frequency to one or more usable range thresholds to determine if the frequency is within a range of calibrated frequencies;
calculating a valid forward power flag by comparing the forward power to a forward power threshold;
retrieving a lower encoded motor step value and an upper encoded motor step value from a calibration table using a lower adjacent frequency and an upper adjacent frequency, the lower adjacent frequency and the upper adjacent frequency both adjacent to the frequency in the calibration table;
calculating an interpolated motor step value between the lower encoded motor step value and the upper encoded motor step value;
driving a motor to change a position of a contactor coupled to a tuning coil based on the interpolated motor step value, the contactor in contact with the tuning coil; and
comparing a voltage standing wave ratio (VSWR) to a VSWR threshold and triggering a second retrieval of the lower encoded motor step value and the upper encoded motor step value if the VSWR is greater than or equal to the VSWR threshold.
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