Compact frequency adjustable portable antenna
AssigneeCompact Antennas, LLC
InventorDonald P. Labriola, II
Life of this patent
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Abstract
A compact mobile high-frequency Antenna that quickly and quietly self-adjusts to minimize Voltage Standing Wave Ratio (VSWR). Includes a compact tuning coil and a rolling contact. A Reentrant cap serves as a capacitive top hat. A spiral cut enhances the efficiency is this very short antenna. A tough insulating tube covers the antenna to serve as a radome protect the user from RF burns. The use of rolling contacts on a smooth inside diameter of the tuning coil greatly reduces the force to move the contactor as well as the acoustical noise generated when tuning. A controller drives a servo motor to position the contactor to the optimal position within the tuning coil and selects the impedance to connect between the unused end of the tuning coil and the feed point of the antenna to optimize VSWR.
Claims19
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.
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;
- 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 the 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 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.
A compact frequency adjustable (CFA) portable antenna comprising:
- a tuning coil wound from flat wire, the tuning coil coupled to a multi-reentrant top cap structure;
- a contactor in contact with the tuning coil;
- a motor coupled to the contactor for moving the contactor;
- and
- a controller capable of measuring a broadcast frequency.
Dependencies are inferred from the claim text.